# 2013

Joseph Millette Sophisticated R/C 9/13/2013 

# Ardu

- Copter Setup and Tuning

ManualPage | 2



## Table of Contents
What is a Multi

- Copter and How Does it Work

................................ ................................ ............................ 7
The Multi

- Copter System

................................ ................................ ................................ .............................. 9
Multi

- Copter Demo illustrating Manual and Automatic Control

................................ ................................ .. 9 Important Elements for Multi

- Copters

................................ ................................ ................................ ....... 10 Significant Design Considerations for Multi

- Copters

................................ ................................ .................. 11 Ready To Fly or Build Your Own

................................ ................................ ................................ .................. 12

DIY

- Drones

................................ ................................ ................................ ................................ .................. 13 APM: Copter Safety

– R ead Before Flying

................................ ................................ ................................ ... 14 First Flight

................................ ................................ ................................ ................................ .................... 20 Setting up Flight Modes

................................ ................................ ................................ .......................... 20 Simple and Super Simple Modes

................................ ................................ ................................ ............ 21

No rmal Mode

................................ ................................ ................................ ................................ .............. 22 Simple Mode

................................ ................................ ................................ ................................ ........... 23 Super Simple Mode

................................ ................................ ................................ ................................ . 26 Use a 3 position switch to select Normal, Simple or Super Simple Mode

................................ .............. 27
Stabilize Mode

................................ ................................ ................................ ................................ ........ 29

Overview

................................ ................................ ................................ ................................ ................. 29 Moving the Pitch and Roll

................................ ................................ ................................ ................... 29 Moving the Yaw

................................ ................................ ................................ ................................ .. 29 Moving the Throttle

................................ ................................ ................................ ............................ 29 Tuning PID

................................ ................................ ................................ ................................ ........... 29 Tuning Yaw

................................ ................................ ................................ ................................ .......... 30
Altitude Hold Mode

................................ ................................ ................................ ................................ 32

Overview

................................ ................................ ................................ ................................ ............. 32 Using Alt Hold Mode

................................ ................................ ................................ ........................... 33 Adequate Pow er and Adjusting your Throttle Center position to Hover

................................ ........... 33 Tuning

................................ ................................ ................................ ................................ ................. 34
Loiter Mode

................................ ................................ ................................ ................................ ............. 36

Overview

................................ ................................ ................................ ................................ ............. 36 Using Loiter Mode

................................ ................................ ................................ ............................... 37 OF_Loiter Mode

................................ ................................ ................................ ................................ .. 37Page | 3

Tuning

................................ ................................ ................................ ................................ ................. 37
RTL Mode

................................ ................................ ................................ ................................ ................ 39

Overview

................................ ................................ ................................ ................................ ............. 39 Options (User Defined Pa rameters

................................ ................................ ................................ ..... 40

Notes

................................ ................................ ................................ ................................ ................... 40
Auto Mode

................................ ................................ ................................ ................................ .............. 42

Overview

................................ ................................ ................................ ................................ ............. 42 Using Auto Mode from Gro und and from the Air

................................ ................................ ............... 43 Ending a Mission

................................ ................................ ................................ ................................ . 43 Tuning

................................ ................................ ................................ ................................ ................. 43
Guided Mode

................................ ................................ ................................ ................................ .......... 44

Overview

................................ ................................ ................................ ................................ ............. 44 What you’ll Need

................................ ................................ ................................ ................................ 45

Instructions

................................ ................................ ................................ ................................ ......... 45
Board LEDs and Sounds

................................ ................................ ................................ ............................... 47 APM 2.5/2.6

................................ ................................ ................................ ................................ ............ 47 3DR GPS+Compass Modu le

................................ ................................ ................................ ................. 47

Pre

- Arm Safety Checks(PASC)

................................ ................................ ................................ ..................... 48
To See what has caused the PASC Failure

................................ ................................ .............................. 48 Fixing Specific PASC Failures

................................ ................................ ................................ ................... 49 Arming and Disarming the System

................................ ................................ ................................ .............. 50 Arming the Motors

................................ ................................ ................................ ................................ .. 50 Disarming the Motors

................................ ................................ ................................ ............................. 50 Rate Roll and Pitch P Tuning

................................ ................................ ................................ ....................... 51 Measuring Vibration

................................ ................................ ................................ ................................ ... 53

Save Trim an d Auto Trim

................................ ................................ ................................ ............................. 56

Save Trim

................................ ................................ ................................ ................................ ................. 56

Auto Trim

................................ ................................ ................................ ................................ ................ 57 Flight Test Process

................................ ................................ ................................ ................................ ....... 59
To Test Loiter and Altitude Hold:

................................ ................................ ................................ ............ 59 What to Expect?

................................ ................................ ................................ ................................ ...... 59 Advanced Configuration and Tuning

................................ ................................ ................................ .......... 61Page | 4

Compass Setup

................................ ................................ ................................ ................................ ............ 62 Live Calibration of compass offsets

................................ ................................ ................................ ........ 62 Compassmot

- compensation for interference from the PDB, ESC, or motors

................................ ........ 63 Tuning Declination in

- flight

................................ ................................ ................................ ..................... 64 Automatic learning of offsets during flight

................................ ................................ ............................. 65 Log based calibration of offsets

................................ ................................ ................................ .............. 65 Manually entering declination

................................ ................................ ................................ ................ 66
Fail

- safes

................................ ................................ ................................ ................................ ..................... 68
Throttle Fail

- safe

................................ ................................ ................................ ................................ ..... 68
Throttle Fail

- Safe Setup

................................ ................................ ................................ .......................... 69

Receiver set

- up:

................................ ................................ ................................ ................................ .. 69 APM Setup

................................ ................................ ................................ ................................ .......... 69 Testing for correct operation of Throttle Fail

- safe

................................ ................................ ................. 70 Battery Fail

- safe

................................ ................................ ................................ ................................ ...... 71
GPS Fail

- safe

................................ ................................ ................................ ................................ ............ 72
Ground Control Station Failsafe

................................ ................................ ................................ .............. 72

Geo

- Fencing

................................ ................................ ................................ ................................ ................ 74

Overview

................................ ................................ ................................ ................................ ................. 74 Enabling the Fence in Mission Planner

................................ ................................ ................................ ... 75 Enabling the fence with Channel 7 or 8

................................ ................................ ................................ .. 75 Setting Channel 6, 7, or 8 options

................................ ................................ ................................ ............... 77 Here are the options:

................................ ................................ ................................ .......................... 78
Check Ch7 & Ch8 PWM values reach 1800

................................ ................................ ............................. 78 Tuning

................................ ................................ ................................ ................................ ......................... 79 Basic performance troubleshooting

................................ ................................ ................................ ....... 80

In

- flight tuning

................................ ................................ ................................ ................................ ........ 82 Here are all the parameters one can tune:

................................ ................................ ............................. 83 Method 2: Flying Attitude Tuning with CH6:

................................ ................................ .......................... 8 4 Attitude PID Tuning

................................ ................................ ................................ ................................ ..... 85

Overview

................................ ................................ ................................ ................................ ................. 85 PID Rate Tuning

................................ ................................ ................................ ................................ ....... 85 PI Control Tuning

................................ ................................ ................................ ................................ .... 86Page | 5

Altitude Hold Tuning

................................ ................................ ................................ ................................ ... 87
PI Control

................................ ................................ ................................ ................................ ................ 87
PID Rate Control

................................ ................................ ................................ ................................ ...... 87 Loiter and Navigation Tuning

................................ ................................ ................................ ...................... 88
PI Control

................................ ................................ ................................ ................................ ................ 88
PID Rate Control

................................ ................................ ................................ ................................ ...... 88 Sensor Testing

................................ ................................ ................................ ................................ ............. 89 Connecting to Mission Planner

................................ ................................ ................................ ............... 89 Mission Planning and Analysis

................................ ................................ ................................ .................... 90
Here are some of the features of Michael Oborne’s Mission Planner:

................................ .................. 90 Planning a Mission with Waypoints and Events

................................ ................................ ..................... 90 Basic Waypoint Commands

................................ ................................ ................................ .................... 91 Tips

................................ ................................ ................................ ................................ ...................... 91 Setting a Home Position

................................ ................................ ................................ .......................... 92

Instructions

................................ ................................ ................................ ................................ ............. 92
Auto Grid

................................ ................................ ................................ ................................ ............. 94 Basic Waypoint Commands

................................ ................................ ................................ ................ 94

Data

- flash Logs

................................ ................................ ................................ ................................ ............ 98 Log Types (Data

- flash vs. tlog)

................................ ................................ ................................ ................ 98 Setting what data you want to record

................................ ................................ ................................ .... 98 Downloading Logs with the Mission Planner

................................ ................................ ........................ 101 Viewing the contents

................................ ................................ ................................ ............................ 102 Message Details (APM: Copter specific)

................................ ................................ ............................... 104 Viewing KMZ FILES

................................ ................................ ................................ ................................ 109
Mission Planne r Telemetry Logs

................................ ................................ ................................ ............... 110 Setting the data rate

................................ ................................ ................................ ............................. 110 Playing back missions

................................ ................................ ................................ ............................ 110 Creating 3d images of the flight path

................................ ................................ ................................ ... 112 Extracting parameters and Waypoints

................................ ................................ ................................ . 112 Graphing data from a flight

................................ ................................ ................................ ................... 113 Using a Ground Station

................................ ................................ ................................ ............................. 114
Guided Mode

................................ ................................ ................................ ................................ ........ 115Page | 6

APM 2.6

................................ ................................ ................................ ................................ ................. 116 Using the APM 2.5/2.6 En closure

................................ ................................ ................................ ......... 117 Powering the APM 2.5/2.6 Board

................................ ................................ ................................ ......... 117 Alternative ways to power your board

................................ ................................ ................................ . 119
3DR Power Module

................................ ................................ ................................ ........................... 119 A Non technical Description of the Power Supply Requirements

................................ ........................ 119 Power Supply Rails Connected Requirements (JP1 Installed)

................................ .............................. 120
No Power Module and No Servos and Power provided by BEC from ESC

................................ ............ 120 No Power Module but using Servos and a high power External BEC

................................ ................... 120 No Power Module but using Servos and multiple BECs from ESC’s (A BEC for each Servo)

................ 121 Power Supply Rails Not Connected Requirements (JP1 Not Installed)

................................ ................. 121

Power Mo dule and No Servos

................................ ................................ ................................ .............. 121 Power Module and using Servos with External BEC power

................................ ................................ .. 122 Power Module and using Servos with BEC power from one ESC

................................ ......................... 122 Power Module and using Servos with BEC power from one ESC

................................ ......................... 122 No Power Module and using Servos with BEC power from two ESCs

................................ .................. 122 APM 2.5/2.6 Connections

................................ ................................ ................................ ......................... 124 Connecting your R/C Inputs and Motors

................................ ................................ ................................ .. 125 Connecting the RC inputs

................................ ................................ ................................ ...................... 125

Connec ting the RC Outputs to the Motors

................................ ................................ ........................... 126 Recognizing the clockwise and counter

- clockwise propellers

................................ ................................ .. 128 Checking the motor direction the simple way

................................ ................................ ...................... 129 Checking the motor direction with the CLI

................................ ................................ ........................... 129 Glossary

................................ ................................ ................................ ................................ ..................... 131 Pitfalls/Lessons Learned

................................ ................................ ................................ ............................ 136
Introduction

................................ ................................ ................................ ................................ .......... 136 Assembly

................................ ................................ ................................ ................................ ........... 136 Configuration

................................ ................................ ................................ ................................ .... 136 Flying

................................ ................................ ................................ ................................ ................. 137Page | 7 

## Revision History

Date ChangesPage | 8



## What is a Multi

- Copter and How Does it Work
A multi

- copter is an aerial vehicle whose motion is controlled by speeding or slowing multiple downward thrusting motor/propeller units.

 A Multi

- Copter is one of the simplest powered aerial vehicles imaginable: A bunch of fans pointing at the ground which pushes you up.

 Multi

- Copters are completely aerodynamically unstable and absolutely require computer control for stable flight.

 As a result, Multi

- Copters are entirely “Fly by Wire” systems and if the computer isn’t working, you aren’t flying.

 The Quad

- Copter shown above is the simplest type of mul ti

- copter, with each opposite pair of motors spinning in opposite directions.

 This allows the copter to turn (Yaw) right or left by speeding up one pair and slowing the other pair of motors.

 Horizontal motion is accomplished by speeding up motors (increasi ng thrust) on one side and reducing it on the other.

 This causes the copter to tilt (Roll or Pitch) in the desired direction of motion and thrust is re

- equalized.

 The angle of the copter is generally representative of its speed in that direction.

 To hover the copter compensates for disturbances (gusts of wind) by tilting automatically against the direction of the disturbance.

 In order to accomplish this, the copter has electronic “gyros” which sense level in 3 dimensions.

 In addition, they may also have ele ctronic “accelerometers” which sense displacement in 3 dimensions.

 Altitude control or change is accomplished by speeding up or slowing down all motors at the same time.Page | 9



## The Multi

- Copter System

In order to be able to fly you need:

 The Multi

- Copter itsel f, including the frame, motors, electronic speed controls, propellers and a battery.

 A Flight Control computer or Autopilot provides stabilization and in more advanced systems (as above), automatic control.

 A radio control transmitter and receiver in order to send the Multi

- Copter your own instructions.

 A personal computer in order to program the computer and optionally for use as a telemetric ground station.



## Multi

- Copter Demo illustrating Manual and Automatic Control

 T he demo begins in “Stabilize Mode” which provides inertial stabilization and permits manual flight control.

 In “Loiter Mode” the Copter automatically maintains position and altitude but permits manual override.

 “Simple Mode” enables the copter to be flown without regard to the copters orien tation (the direction it is facing).

 “Auto Land” causes the copter to descend and disarm its motors when it has landed.Page | 10



## Important Elements for Multi

- Copters

 The primary requirement of a Multi

- copter is that it possess more than sufficient power propel itself straight up.

 Multi

- Copters have been made feasible by the development of extremely powerful Lithium batteries.

 Previous battery technologies have insufficient capacity and are too heavy for a reasonable duration of hovering flight.

 Brushless electri c motors and electronic speed controllers also enhance flight performance, endurance and reliability.

 Carbon fiber, aluminum and fiberglass make strong light frames possible further increasing efficiency and performance.

 The Flight Controller / Autopilot / Computer are the brain that lets the Multi

- Copter accomplish marvelous things.

 Our group relies on the APM, PX4 and Pixhawk Flight Controllers and they each have considerable capability.

 The Flight Controllers contain or attach to the wide variety of sens ors necessary for automatic control.

 Ours systems include: 3 axis gyro, 3 axis accelerometer, compass/magnetometer, barometer/altimeter and GPS.

 The Autopilot interfaces to the copters motors, radio control receiver and optional telemetry and camera contro ls.

 Modern 2.4 GH z radio control systems provide fast and very reliable in flight communication with the multi

- copter.

 An excellent Mission Planner computer program allows us to load the operational “firmware” into the Autopilot.

 The Mission Planner progra m also permits us to load custom parameters and instructions to our Multi

- Copter.

 Additionally we can use the Mission Planner to read and analyze flight logs recorded to the Autopilot while in flight.

 Finally the Mission Planner program can operate as a te lemetric “Ground Station” displaying current flight data.Page | 11



## Significant Design Considerations for Multi

- Copters

 A Multi

- Copter is a highly stressed system so it is important that all components are carefully matched to its capability.

 Projected weight, perf ormance, flight time and payload all require careful balancing to achieve a good result.

 A high performance, light weight Quad

- Copter has different needs than a heavy lift, camera carrying Hex or Octo

- Copter.

 Frame size and weight, motor/prop requirements, power (battery) needs, and payload are important considerations.

 A small Quad

- Copter is ideal to learn to fly on. They are easy to fly, light, tough, relatively safe and survive mishaps well.

 A big Hex or Octo with a camera rig is seriously expensive, muc h more hazardous and is inappropriate to learn on.

 It will also tend to break much more destructively (and expensively) than a relatively light and unencumbered Quad

- Copter.Page | 12



## Ready To Fly or Build Your Own

 There are excellent arguments on both sides of this issue, you can buy excellent ready to fly Copters or easily build your own.

 You can get tiny little toy grade Quad

- Copters for under a hundred dollars with everything that are still remarkably easy to fly.

 Some are so small that they represent very li ttle hazard even indoors and they are so light that they are also very sturdy.

 The tiny Traxxas QR1 Quad

- Copter is an excellent and inexpensive RTF Quad

- copter that is great for a first experien ce.

 Alternatively you might consider an inexpensive ARF “Almost Ready to Fly” semi build it yourself approach.

 The DJI Flame Wheel F450 and F330 ARF kits are an excellent value and we have a Wiki walk through assembly page.

 These Copters will survive many hours of “learning” and the walk through article utilizes our state of the art flight controllers.

 My little F330 with an APM 2.0 Flight Controller below has logged (Many) hours and survived numerous sub

- optimal “landings”.

 Photography is not my thing, but click on it for a bigger picture.

 You can also start with an excellent configurable kit Quad

- Copter such as the Ardu

- Copter shown at the top of this page.

 Or the new state of the art Iris Quad

- Copter that incorporates the very powerful Pixhawk flight controller and advanced construction.Page | 13



## DIY

- Drones

 Our group DIY

- Drones are primarily devoted to automatic control and our emphasis is on the use of highly capable flight controllers.

 We seek to have lots of automatic and robotic capabilities such as precision point to point travel, waypoints and mission following.

 The APM, PX4 and Pixhawk flight controllers manufactur ed by 3DR , our supporting Corporation embody those capabilities.

 You can certainly start with and enjoy a little RTF Traxxas to get your feet wet and see if this appeals to you.

 But when and if you want to go to the next level, DIY

- Drones stand ready to he lp you reach for the sky.

 We are the leading (and bleeding) edge but no

- body offers you more opportunity to do more, more quickly than DIY

- Drones

.Page | 14



## APM: Copter Safety

– Read Before Flying Your first priority must be the safety of people!

1. Crashes can happen, because of pilot error or hardware or software malfunction.

2. It is very important to have excess power available.

A. If you have insufficient power, the automatic controls can require more throttle than is available and destabilization may result.

B. Idea lly your copter should be able to hover at about 50% throttle (mid stick).

3. Especially while you are learning, it is recommended that you avoid expensive, stiff, ultra

sharp carbon fiber props.

A. Get cheaper, more flexible and more breakable plastic propeller s.

B. Some of the super carbon fiber ones can cut well than a Ginsu and while they are almost indestructible

– You are not.

4. If you are flying anywhere near other people, you are putting them at risk!

A. Be sure to maintain safe distances between yourself, and sp ectators and your copter.

B. Circumstances will require that you will need to make your own determination of what is a “safe distance” from people and property.

C. At a minimum, consider: at least 10ft (3m) but not further than 30ft (10m) from you.

D. Keep all othe r people, property and obstacles considerably further away from your copter.

E. Ensure that no one gets between you and your copter.

F. Spectators should always be a safe distance behind the pilot.

G. If people intrude beyond what you have determined to be the “saf e” area, land immediately and do not take off until they are clear.

H. At full power, an average sized multi

- copter can exceed 20 mph (32 km/h), can ascend to hundreds of feet and easily travel more than a mile in distance before running out of battery.Page | 15

5. Alway s ensure the battery cable is NOT connected to the power distribution board or harness until you are ready to fly.

A. Always turn on the transmitter and ensure the throttle stick is all the way down BEFORE connecting the battery.

B. After landing the first thing you should do is disconnect your battery cable.

C. Do not turn off the transmitter until after you have disconnected the battery.

D. Always remove your props while you are testing motors, your hands, arms and face and those of your friends will thank you.

E. When the battery is connected, always assume the motors are armed; you can check with a short throttle pulse.

F. Don’t pick up the model and the radio at the same time, you may bump the throttle.

G. Do not attempt to fly longer than your batteries safe capacity, it is very bad for the battery and can cause a crash.

6. The APM and PX4 flight controllers we use incorporate a motor arming safety feature.

A. Immediately prior to flight after the battery has been connected, the RC transmitters throttle stick needs to be held do wn and to the right for several seconds to arm the
motors.

B. After landing your first response should be to hold the throttle down and to the left for several seconds to “Disarm” the motors. * Disarm condition can be tested by moving the throttle stick up, i f the motors do not move it is disarmed.

C. Even when disarmed, the throttle stick should always be kept in the full down position except when flying.

7. Get used to switching back to Stabilize mode from other modes and reassuming full manual control.

A. This is th e single most important recovery technique (practice it).

B. Stabilize mode can have Simple mode added to it, but if you do you should then practice with it till you are proficient.

C. Do not start using any other modes than Stabilize or Stabilize plus Simple un til you are VERY comfortable flying your copter.Page | 16

8. Important primary response to a crash, inadequate landing or unknown flight controller state.

A. The first thing to do is throw a towel over your copters propellers (Propellers may start spinning unexpectedly).

B. Then immediately disconnect the battery.

C. A large towel is your most important piece of safety equipment followed by a fire extinguisher and a first aid kit.

D. Generally better to use the first one than the last one.

9. When testing or flying any of the (waypoi nt) navigation modes (using GPS):

A. Ensure that your GPS has “Lock” before arming and takeoff.

B. Check that your home position on the Mission Planner is in fact correct.

C. If the GPS does not accurately report your home position, reboot and wait for 8 or more

sa tellites (not just 3D lock) and check again.

10. Always follow the law:

A. Our personal use of Multi

- Copters (models in general) is continually under attack by those who fear ‘drones’ and invasion of privacy. If you break the law, or invade someone’s privacy, or put them in harm’s way, you threaten the future of our personal use of models. Please, understand the law and the rights of others

– and fly accordingly.

B. Most countries have a prominent model aircraft organization. In the USA that is the AMA . Review the AMA safety code . Working with the FAA and other government organizations, the AMA has established (and continues to update) rules for UAV’s and for FPV flight . If you are in the USA (or not), read these documents! The AMA h as a strong lobbying group that will help protect our rights. Get involved and support your country’s model aircraft organizations

– and help protect our right to fly.Page | 17

Most important: Keep a safe distance between your Copter and People!
These tips can also help protect your multi

- copter from damage.

1. Avoid sudden or extreme transmitter control stick deflections.

A. Move the control sticks in small measured increments and don’t “yank” on them.

B. If the copter is properly calibrated and balanced it should require only small stick inputs to control altitude, direction and speed.

2. Your copter should be more or less stable on the horizontal plane without any control inputs.

A. If you are “fighting” the copter, land and fix it

– something is not right

– Hardware adjustment or software calibration may be required.

3. Be especially careful of large throttle inputs, as a copter can gain (or lose) altitude very rapidly.

4. Because Multi

- Copters are symmetrical it is especially easy to lose Visual Orientation.

A. For manual flight modes, maintaining a clear vision of the Copters Orientation (direction it is facing) is the most critical part of successful flight.

B. Especially while learning it is very important to keep your copters appropriately close to you to aid in maintaining visual orie ntation.

C. Generally: more than 10ft (3m) but not further than 30ft (10m) from you.

D. If the copter gets further than about 100ft (30m) it starts getting difficult to be able to maintain orientation and can easily crash.

E. If you lose Yaw orientation while flyin g in Stabilize mode, try only flying forward and using yaw to steer like a car.

F. It is much better to simply descend and land rather than have an orientation

induced crash or worse still

– a fly away

.
G. Fly

- Always often happen when the copter is commanded to tilt back towards the pilot but has rotated in the meantime and is so far away that orientation is lost.

H. Result: the copter flies further away and crashes or is lost.

5. Always have Stabilize mode as the (Go To) one of your mode switch options.Page | 18

6. High or unexpe cted winds or gusts can make flight considerably more difficult.

A. High winds can prevent forward progress or spin the copter around causing you to become disoriented.

B. The higher you are, the more likely high winds will be a problem.

C. Switching to Stabilize m ode and landing before you reach your skill limits can help you save your copter.

D. Avoid flying at high speed or high altitude until you have gained considerable confidence in both manual and automatic modes.

E. When flying around trees or buildings it is very easy to lose visual orientation or even to lose sight of the copter completely.

F. Gusting winds around objects can also worsen the problem.

G. Radio signal loss can also occur.

H. If your copter is approaching a potentially interfering object, immediately switch to stabilize mode and land or retrieve the copter to your location.

7. Ardu

- Pilot specific safety modes: RTL, Fail

- Safe and Geo

- Fence.

A. RTL can provide a safe Return to launch if it starts to get away from you.

B. Set up a Fail

- Safe on Radio Fail with an RTL or Descend response to save your Copter and prevent Injury.

C. Geo

- Fence establishes an automatic flying perimeter that will force your copter to stay in a safe proximity.

D. Do not rely solely on the above safety modes, always be ready to take back control in stab ilize and set the copter down.

E. Especially do not rely on the above safety modes to perform maneuvers or training that you would otherwise consider dangerous.

F. These modes are a supplement to, not a replacement for sound safety practices.Page | 19

8. On your first takeo ff after tuning or hardware setup:

A. In stabilize mode advance the throttle very slowly until the copter is almost hovering.

B. If the copter is trying to flip over turn it off and correct the problem.

C. A motor could be turning the wrong direction.

D. Or a wrong di rection prop could be installed.

E. If it tries to rotate on its axis or fly off in some direction.

F. The transmitter or RC setup in Mission Planner may be incorrect.

G. A motor or ESC may not be performing properly.

H. The wrong props may be on the wrong motors.

I. Whe n all problems are fixed it should be fairly easy to get the copter to hover a foot or 2 above the ground.

J. If a stable and stationary hover a foot or 2 above the ground cannot be achieved, land and fix the problem until it can.

9. When flying FPV “First Perso n View” (with a video camera), Have your modes set to: STABILIZE, SIMPLE, and RTL.

A. Ensure RTL is working properly before using FPV.

B. Use Stabilize mode to fly FPV.

C. If you lose your FPV video, you can switch to Simple or RTL to get back.

10. Make sure your batte ry can’t fall out.

A. Use a Velcro Strap to hold it in place.

B. You can also use adhesive backed Velcro under the battery.Page | 20



## First Flight This section covers the information you will need to know for your first flight and also some basic configuration to get your copter flying reasonably well. Please follow each of the links below. 

### Setting up Flight Modes There are 13 flight modes available in APM: Copter, 9 of which are regularly used. You can set these up by doing the following:

 Turn on your RC transmitter

 Connect the APM/PX4 to the Mission Planner

 Go to the Software > Flight Modes screen

 Note as you move your transmitter’s flight mode switch (channel 5) the green highlight bar will move to a different position.

 Use the drop

- down on each line to select the flight mode for that switch position ensuring that at least one switch position is left assigned to Stabilize

 Optionally check the Simple Mode checkbox for that switch position

 When finished press the “Save Modes” button.

In general when first starting t o use APM: Copter you should progress through the flight modes in the order listed below, being sure that you are comfortable with each before progressing to the
next. Click on any of the flight modes below for more details.

 Stabilize

 Alt Hold

 LoiterPage | 21

 RTL

 Auto

 everything else including ACRO , Guided , Circle , Position , LAND
Most transmitters provide a 3 position switch

. If you do not wish to use the mission planner you can also set the flight modes through the CLI (command line interface)

. With some small code modifications you can set

- up custom flight modes which are combinations of existing flight modes as described in the de veloper section

. 

### Simple and Super Simple Modes

 Simple Mode and Super Simple Mode are used in combination with the other Flight Modes.

 These modes can:

 Greatly simplify learning how to fly.

 Provide useful photo and video capability permitting the yaw to be used to “aim” the

camera.

 Permit regaining control if the pilot loses sight of the visual orientation of the copter. Copter’s orientation is not apparent.

 These modes work by setting the copter’s orientation relative to a fixed direction or location regard less of the actual orientation of the copter.

 Simple Mode allows you to fly your copter relative to the copters orientation at take off.

 And Super Simple Mode allows you to fly (even more simply) relative to your home location.

 After takeoff in either Simp le or Super Simple mode actual copter orientation (Yaw) is irrelevant, and the following controls apply: Pitch out = away, Pitch back = return and Roll left = go left, Roll right = go right.

 One of most important uses of Simple and Super Simple mode is to allow you to recover from loss of visual orientation of your copter.

 This is a very common problem for copters as visual orientation is often hard to determine or maintain even under ideal conditions.

 Although flying with Simple or Super Simple modes is mu ch easier than normal flight it can initially be confusing especially for experienced RC pilots used to flying Normal mode.Page | 22  For this reason it is a very good idea to get used to flying in both Simple Modes before depending on them in an emergency.

 If you d o switch to Simple mode in flight you need to be facing the same direction as you were at takeoff.

 If you do switch to Super Simple mode in flight you need to be standing approximately at your launch location



## Normal Mode

 In Normal Modes flight and transmit ter stick position is relative to the Orientation of the copter.

 This means that with the copter oriented away from you and flying away from you the controls operate as you would expect.

 But flying back towards you and oriented towards you, the controls a re reversed.



### In Normal mode fly from the standpoint of the copters orientation (as though you were a pilot in the copter).Page | 2 3



### Simple Mode Simple mode is similar to the “care free” mode on other multi

- copters

.

 Simple mode allows you to “fly the compass, not the copter”.

 You fly your copter as though it were pointed in the direction it was pointed at take off regardless of its subsequent orientation.

 So, basically you can fly it all around you so long as you face the same direction as at take off.

 If you stand behind your copter and take off with it pointed directly away from you it will fly normally.

 But if you yaw the copter sideways it will still fly as though it were pointing directly away from you.

 Basically pitch forward on stick = copter going away from you, pitch back = copter coming back to you.

 And Roll left on stick = copter goes to the left, Roll right = copter goes to right.

 As long as you face the same direction the copter will go in the stick direction regardless of its orientation (yaw).

 You can spin it in any direction you wish and the copter will still behave exactly as it did at take off.

 Simple mode is a very easy way to fly!

 Simple mode solves the problem of maintaining visual orientation which is easily lost on any copter.

 You don’t need to worry about the orientation of the aircraft; you just fly according to your launch position.

 Basically if you start with the copter facing North, North is always “forward” in your RC stick position.

 Simple mode is actually a flight style modifier for the o ther flight modes of APM: Copter and is used in conjunction with them.

 Simple Mode is specified by checking the Simple Mode box next to the flight mode it is wished to modify in the Flight Modes section of the Configuration tab of the Mission Planner.

 Sinc e simple mode uses the initial compass direction to determine (virtual orientation), it does not require GPS lock.Page | 24

In Simple Mode stay facing the same direction and even if you move around, the copter will always fly as described. This animation shows si mple mode at work with rolling right and pitching forward as examples. The spinning copter shows how, no matter which way the copter faces, the controls remain
constant.Page | 25

 To use Simple mode set the copter on the ground pointing away from you.

 Arm the copter . (Unless one of the primary Flight Modes requires GPS it is NOT necessary to acquire GPS lock).

 Advancing the Pitch control stick forward causes the copter to fly away from you and Pitch back causes it to fly towards you.

 Moving the Roll control stick to the right causes the copter to go to the right and Roll left causes it to go to the left.

 Moving the Yaw control stick causes the copter to rotate, but its heading does NOT affect direction the copter will go when the Pitch or Roll control is used.

 The Thr ottle control stick controls altitude as is normal for whichever mode is selected as being under Simple mode control.

 For Simple mode the desired orientation is set when the copter is armed.

 Re

- arming the copter will reset the “home” orientation.

 Simple mode can be selected as the manual control mode of any other mode, as shown in the Mission Planner setup screen above.

 Simple mode is especially useful for flying at the edge of visual range, but not so useful for FPV.

 If your copter has gotten to be too f ar away you can use a Simple mode specified Stabilize mode to bring it back to a closer range without using RTL mode (RTL does not work if the GPS has no fix).

 Simple mode can even be useful for mechanical failure recovery.

 You could lose a motor on a hex or Octo setup causing your copter to spin.

 If you switch to a simple mode it can allow you sufficient control to recover and land the copter.

 Providing you have sufficient power in your remaining motors to maintain altitude.

 Simple mode can also be changed with Channel 7 and 8 input.

 If you choose this option of enabling Simple mode via Channel 7 or 8, your normal mode switch settings will be overwritten.

 Yo u can also enable Simple mode via the CLI.

 To enable Simple mode individually, per switch position, open the CLI and go to “setup” and “modes”.

 Use the roll control to set the mode per switch position.

 Use the rudder control to set the Simple mode option p er switch position.

W ARNINGS :

 When using Simple Mode, you (the pilot) must stay in the same orientation.

 If you turn 90°, then pitch will become roll!

 If you want to rotate yourself and keep Simple mode

– - simple, you need to land, disarm and reorient the front of the copter to your new away from the pilot direction and then re

- arm and take off.Page | 26



### Super Simple Mode

 Super Simple Mode uses your home position to maintain orientation rather than initial vehicle orientation.

 So basically you can fly it all arou nd you changing your and its orientation so long as you stay on the same spot.

 This mode does require GPS lock because (virtual orientation) is relative to launch spot rather than launch orientation.

 Super Simple mode uses your home position as the reference for forward.

 If you fly > 10m away, the copter will constantly recalculate it’s orientation so that:

 Pitch forward moves the copter away from you

 Pitch back moves the copter towards you

 Roll Left causes the copter to orbit counter clockwise aroun d you towards the left.

 Roll Right causes the copter to orbit clockwise around you towards the right.

 The Yaw control stick will cause the copter to rotate, but its heading does NOT affect direction the copter will go when Pitch or Roll control is used. (R oll and Pitch motion is relative to the GPS home position determined at take off not relative to copter heading).

 The Throttle control stick controls altitude as is normal for whichever mode is selected as being under Super Simple mode control.

 This makes for very intuitive flying and removes the need to worry about the original orientation.

 Inside the 10m circle, the most recent orientation is kept.

 In order to successfully use Super Simple mode:

 You must use the GPS and you must set home by achieving GPS lock (GPS blue LED and APM blue LED on solid not blinking) before arming and takeoff.

 If you fly around and achieve lock in the air, this will be your new home location.

 Flying 10m from this location will suddenly reorient the copter.

 To avoid this issue w ait till you have GPS lock (GPS blue LED and APM blue LED on solid not blinking)before arming and flying when you are going to use Super Simple mode.

 As long as you stay in the same spot, as you fly the copter around you and regardless of the direction you (or it) are facing.

 It will always go directly away from you if you pitch forward and return to you if you pitch back.

 And it will always go to the left if you roll left or go to the right if you roll right.

 Super Simple mode is enabled by setting the par ameter named SUPER_SIMPLE to 1 (0 disabled default) in the Parameter List in the Mission Planner’s Configuration section.

 When SUPER_SIMPLE is enabled all modes selected as simple will be in fact Super Simple.

 Really Super Simple right!Page | 27



### In Super Simple Mo de, stay at the launch location and even if you turn around with the copter in front of you it will fly as described. 

### Use a 3 position switch to select Normal, Simple or Super Simple Mode

 A two position switch will select between Normal and either Simple o r Super Simple operation as illustrated below.

 In Mission Planner select either channel 7 or channel 8 and then select either “Simple Mode” or “Super Simple Mode”.

 Warning! The 3 Position Switch Option will not be available until version 3.1 of the Ardu

- copter firmware.

 A 3 position switch connected to either Ch7 or Ch8 will select between Normal, Simple and Super Simple Modes.

 For 3 position switch operation, in Mission Planner set channel 7 or channel 8 to “Super Simple Mode”.

 For 3 positions switch ope ration insure that your switch low PWM is below 1200 and your high PWM is above 1800.

 For a three position switch, the assignments are as follows.

 Low position : Disable (Normal operation)

 Mid position : Simple mode enabled

 High Position: Super Simple mode enabled.Page | 28

 In addition to safe recovery, the ability to select between modes can be especially useful for filming and photography.

 It can allow the copter to be pointed (yawed) as desired for the camera orientation while permitting normal flight control.Page | 29



### Stabilize Mode Stabilize mode is APM: Copter’s manual flight mode. This page provides tips for flying in stabilize and methods for tuning your copter to fly optimally in stabilize mode.



### Overview Stabilize mode is the primary operating mode for flying APM: Copter and can be considered its manual flight mode. Stabilize automatically levels the multi

- copter and maintains the current heading, while allowing the pilot full control over the throttle. Stabilize is good for general flying and FPV. The autopilot

mu st always initially be set to stabilize mode in order to be able to arm the ESCs before takeoff. It is VERY important to be able to easily and rapidly switch back to stabilize mode from any other mode in order to regain control from any unexpected or undes irable flight behavior.
Moving the Pitch and Roll

 Moving the (right) control stick in any direction will cause the copter to tilt and move in that direction.

 Releasing the Pitch and Roll control stick will cause the multi

- copter to re

- level itself.

 Input on the (Pitch and Roll) control stick is approximately equal to the angle of the copter.

 The default control angles are plus and minus 45 degrees.

 Prevailing wind is not automatically compensated for and the multi

- copter will drift with the wind unless the operator counters with input on the Pitch and Roll control stick.
Moving the Yaw

 Moving the (left) control stick left or right will cause the copter to rotate at a rate based on the amount of stick input.

 Releasing the (Yaw) control stick will cause the c opter to record and maintain the new heading.

 The current heading is maintained automatically when the Yaw control stick is centered right and left.
Moving the Throttle

 Moving the (left) control stick up or down will cause the copter to ascend or descend

a ccordingly.
Tuning PID

 The Stabilize Control PI and Stabilization Angular Rate Control PID interacts to control the copter in Stabilize mode.

 The Stabilization Angular Rate P value is the single most important value to set correctly for your copter.

 The hi gher performance your copter is, the lower this number should be.

 A copter that accelerates very quickly might have a number like 0.08 and one that is more sluggish could have a number like 0.18.

 If you get this right generally your copter will fly accepta bly in all modes, but tweaking the PIDs for your copter will let you optimize performance.Page | 30

 The RATE_RLL PID and RATE_PIT PID are normally locked to the same values as the Angular Rate Control PID in the Mission Planner.

 The STB_PIT PI and the STB_RLL PI ar e normally locked to the same values in the Stabilize Control PI in the Mission Planner.

 For most copters the Roll and Pitch PID values should be the same.

 See AC2_attitude_PID for more detailed tuning information.

 Stable_P is used input the rate of rotation based on control input.

 The higher the P the faster the copter will be asked to turn to get to the desired angle.

 A high P will cause the copter to oscillate back and forth like a seesaw a few times a second.

 A low P will cause the copter to move very slowly. A very low P will cause the copter to feel unresponsive and could cause a crash if the wind disturbs it.

 Stable_I is used to compensate for outside forces that would make your copter not m aintain the desired angle.

 The I term will ramp to hold the desired angle.

 Because the copter rotates to new angles constantly, the I

- term is not that useful in this mode.

 It is used instead to try and hold the copter perfectly level when hovering.

 A limit to the ramp up of the I

- term has been set low to achieve this.

 The output of the Stabilize Control PID is sent to the Angular Rate Control PID whose output directly controls the copters motors.

 Rate_P is used to turn the copter.

 The higher the P the higher the motor response to achieve the desired turn rate.

 This is the single most important value to tune correctly for your copter.

 Default is P = 0.18 for standard Ardu

- copter

.

 A higher performance copter might use a value of 0.08.

 Rate_I is used to co mpensate for outside forces that would make your copter not maintain the desired rate.

 A high I term will ramp quickly to hold the desired rate, and will ramp down quickly to avoid overshoot.

 A low I term will take too long to have an effect and may cause undesirable overshoot. It’s better to have an I

- term of 0 than a poorly chosen I term.

 Rate_D is used to dampen the response of the copter to accelerations toward the desired set point.

 A high D can cause very unusual vibrations and a “memory” effect where the controls feel like they are slow or unresponsive.

 Values of .001 to .008 have all been used, but results will vary according to your multi

copters size and performance characteristics.
Tuning Yaw

 Yaw Angular Rate Control and Yaw Stabilize Control is a lso basic functions for controlling the rate of heading change of the copter.Page | 31

 Yaw Angular Rate Control Determines how much throttle is applied to rotate the copter at the desired speed.

 Yaw Rate P should be set higher to turn faster and lower to turn more slowly.

 Yaw Stabilize Control Determines how fast the copter responds to user or autopilot input.

 Yaw Stabilize P should be set higher get more aggressive control and lower to slow reaction time.

 Too high a Yaw Stabilize Control P value will cause slow wob bles.Page | 32



### Altitude Hold Mode In altitude hold mode, the copter maintains a consistent altitude while allowing roll, pitch, and yaw to be controlled normally. This page contains important information about using and tuning alt hold.

Overview When altitude hold mode (alt hold) is selected, the throttle is automatically controlled to maintain the current altitude. Except for automatic altitude maintenance, alt hold mode operates the same as in stabilize mode. Automatic altitude holding is a feat ure of many APM: Copter flight modes (such as loiter mode) and the information contained here pertain to those modes as well.

In versions 2.9 and later of the APM: Copter firmware, accelerometer

- based “inertial compensation” is also used to maintain altitude. This results in faster compensation and more accurate altitude maintenance, but it also requires vibration damping for your flight controller mounting. Visit the Vibration Dampening page for more information about how to reduce vibrations in your copter.

Warning: The flight controller uses a barometer which measures air pressure as the primary means for determining altitude (“Pressure Altitude”) and if the air pressure is changing in your flight area, the copter will follow the air pressure change rather than actual altitude (unless you are within 20 feet ofPage | 33

the ground and have SONAR installed and enabled ). Below 26 feet, SONAR (if enabled) will automatically provide even more accurate altitude maintenance.
Using Alt Hold Mode When entering alt hold, it is important to be hovering at a stable altitude before engaging alt hold. This is because when engaging alt hold (or any mode that maintains the present altitude automatically), the current throttle stick position is used as a baseline for altitude maintenance, so it is important to have the copter normally hovering near center stick position. The APM will compensate over time for rising or dropping and should end up at the correct altitude, but it is wise to not over depend on this capability. To adjust the position of the throttle stick so it hovers near the center stick position, see the section below on adjusting the throttle center. In all altitude holding modes the throttle stick controls the altitude, not motor speed directly.
While in alt hold mode, altitude can still be manually changed by raising or lowering the throttle control beyond a large centr al dead band. After using manual override to change altitude it is important to re

position the throttle stick back to as near your normal hover position as possible because altitude hold uses the RC transmitter throttle stick center position as the center point for all manual altitude adjustments. When you switch back to stabilize mode from any altitude holding mode, the copter will immediately go in the direction of any throttle stick displacement from the neutral hover position, potentially causing it to drop or rise at an alarming rate.
Altitude hold mode is not approved for takeoff and landing.
! Warning ! You cannot land and turn off the motors in any altitude holding mode. Always switch to stabilize mode to be able to land and disable the motors.
Adequ ate Power and Adjusting your Throttle Center position to Hover

 It is very important to have excess power available.

 If you have insufficient power, the automatic controls can require more throttle than is available and destabilization may result.

 Ideally y our copter should be able to hover at about 50% throttle (mid stick) and anything higher than 70% is dangerous.

 Once you have determined you have sufficient power you can adjust the throttle stick midpoint to be in the center.

 This is important, because wh en you switch to an Altitude Holding mode, actual stick center is used to determine static altitude.

 In an Alt Hold mode if you move the throttle past a + or

– 10% dead band, manual override causes the copter to go up or down.

 The throttle dead band when i n alt

- hold or loiter mode is from 40% ~ 60% of the throttle.

 If you have an over or under powered copter the throttle required in stabilize to maintain a hover may be outside this range.Page | 34  The result being that when you enter an alt

- hold mode your throttle i s outside of the dead band and the copter will climb or descend.

 An operational solution is to simply move your throttle back to center as you engage alt

hold.

 Adjust the THR_MID parameter in Mission Planner’s Adv Parameter List to allow the copter to hove r at throttle stick center.

 If your copter hovers at 40% of throttle stick when in stabilize mode, make THR_MID = 400.

 If it hovers at 60% of throttle make THR_MID = 600, etc.

 THR_MID total range is from 300 to 700 (30% to 70%) and any offset outside of th at range is probably dangerous.

 Warning: If you incorporate expo on your transmitter, that directly increases the size of the Alt Hold throttle dead band.
Tuning NOTE! This information does not yet take into account the effect of inertial compensation, Use Caution!

 The THR_ALT PI and THR_RATE PID interacts to control and adjust the copters altitude in any automatic altitude maintaining mode.

 See Altitude Hold Tuning for more detailed tuning information.

 Altitude Hold PI calculates altitude error in centimeters and feeds it to the controller.

 The first stage of the controller takes the altitude error and decides how fast the copter should go to reach the correct altitude.

 THR_ALT_P is by default .4 or 40 cm/s for a 1m error.

 The desired rate maxes out at 1m/s.

 THR_ALT_I is used to close the gap between the actual hover throttle and current assumed hover throttle.

 For example, if your copter hovers at 52% throttle , and your set point is 4% your copter will fall until it reaches equilibrium with THR_ALT_P times the error.

 This is called a steady state error, and leaves your copter too high or too low.

 THR_ALT_I will increase to effectively raise the throttle to 52%.

 The higher the number the faster it happens.

 If your number is too high it will cause oscillations.

 Throttle Rate PID adjusts the motor thrust to provide the speed that is required from the THR_ALT PI.

 THR_RATE_P is the proportional response and the defau lt is .35.

 Your copter will vary quite a bit depending on the weight and thrust of your motors.

 If your copter oscillates up and down in alt hold, lower this value.

 THR_RATE_I is set to 0 by default.

 It can, in theory, fix issues with a bad THR_RATE_P valu e, but it’s best to just get that tuned well in the first place.Page | 35

 THR_RATE_D is 0.02 by default, but the noise of the Baro sensor can cause issues.

 If the value is too high you will see bad oscillations or pulsing of the motors.

 Once the THR_RATE_P value is dialed in, start at 0, and increment the D value slowly.

 You should see oscillations die down.Page | 36



### Loiter Mode In loiter mode, the copter maintains a consistent location, heading, and altitude. This pages describes what to except when using loiter mode an d provides tips for flying and tuning.

Overview When switched on, loiter mode automatically attempts to maintain the current location, heading and altitude. Wind, PIDs and sensors will affect the effectiveness of maintaining position. The stronger the wind the greater the location deviation will be.

In loiter; the copter’s location can be manually adjusted with the control sticks.

 Horizontal locat ion can be adjusted with the Roll and Pitch control stick.

 The Heading can be reset with the Yaw control sti ck.

 Altitude can also be adjusted with the Throttle control stick.
Since Loiter mode attempts to maintain position, it relies on the GPS which must be on and indicating that it is locked before takeoff. Ensure that both the GPS blue LED and the APM board C blue LED are on steady and not blinking before arming and taking off when Loiter mode is going to be used. For the 3DR uBlox GPS+Compass module, the blue LED is off while acquiring satellites and on blinking when satellitesPage | 37

have been acquired. It is very important to acquire GPS lock before arming in order for RTL, Loiter, Auto or any GPS dependent mode to work properly.

Warning: In loiter mode, the flight controller uses a barometer which measures air pressure as the primary means for determining altitude (“Pressure Altitude”) and if the air pressure is changing in your flight area, the copter will follow the air pressure change rather than actual altitude (unless you are within 20 feet of the ground and have SONAR installed and enabled). Below 26 feet, SO NAR if enabled will automatically provide even more accurate altitude maintenance.

Warning: Loiter mode is not approved for takeoff and landing. You cannot land and turn off the motors manually in Loiter mode. You must switch to Stabilize Mode to land and disarm the motors.
Using Loiter Mode Loiter mode incorporates automatic altitude maintenance; therefore the same usage guidelines apply to altitude hold mode and loiter mode. When entering a mode that maintains the present altitude automatically, the curre nt throttle stick position is used as a baseline for altitude maintenance so it is important to be hovering at a stable altitude before engaging loiter mode. The APM will compensate over time for rising or dropping and should end up at the correct altitude , but it is wise to not over depend on this capability. For more information on setting the throttle’s center, visit the Al titude Hold Mode page.
While in loiter mode altitude can still be manually changed by raising or lowering the throttle control beyond a large central dead band. After using manual override to change altitude it is important to re

position the throttle stic k back to as near your normal hover position as possible. When you switch back to stabilize mode from any altitude holding mode, the copter will immediately go in the direction of any throttle stick displacement from the neutral hover position, potentially causing it to drop or rise at an alarming rate. Remember that, in loiter, the throttle stick now adjusts the altitude, not the motors directly.

OF_Loiter Mode OF_LOITER is a special version of Loiter mode that will use the Optical Flow device to maintain position. It is not yet implemented but work is ongoing. Do Not select OF_LOITER mode until an update of APM: Copter specifies that it is installed and working.
Tuning Tuning PIDs can improve all aspects, but over increasing responsiveness can result in su dden and unexpected loss of control.

 See Loiter and Navigation Tuning for more detailed tuning information.

 Loiter Speed PI and Loiter Rate PI values are used to control the copter.

 Loiter Speed P is used to push the copter to the desired location.

 Loiter Speed I is used to overcome wind.

 Loiter Speed I is overwritten by the copter on the fly and is not user editable.

 Loiter Rate P is used to til t the copter.Page | 38  The higher the P the higher the motor response to achieve the desired turn rate.

 Loiter Rate I is used to compensate for outside forces that would make your copter not maintain the desired rate.

 A high I term will ramp quickly to hold the desired rate, and will ramp down quickly to avoid overshoot.

 A low I term will take too long to have an effect and may cause undesirable overshoot.

 It’s better to have an I

- term of 0 than a poorly chosen I term.Page | 39



### RTL Mode In return to launch (RTL) mode, t he copter navigates from its current position to hover above the home position. The behavior of RTL mode can be controlled by several adjustable parameters. This page describes how to use and customize RTL mode.

Overview When RTL mode is selected, the copt er will return to the home location. By default the copter will first rise to at least 15m before returning home, or it will maintain the current altitude if it is higher.

RTL is a GPS

- dependent move, so it is essential that GPS lock is acquired before at tempting to use this mode. Before arming, ensure that the APM’s blue LED is solid and not blinking. For a GPS without compass, the LED will be solid blue when GPS lock is acquired. For the GPS+Compass module, the LED will be blinking blue when GPS is locke d.
RTL will command the copter to return to the home position, meaning that it will return to the location where it was armed. Therefore, the home position is always supposed to be your copter’s actual GPS takeoff location, unobstructed and away from peopl e. For APM: Copter if you get GPS lock and then ARM your copter, the home position is the location the copter was in when it was armed. This means if you execute an RTL in APM: Copter , it will return to the location where it was armed.Page | 40

Warning: RTL travel speed is determined by WPNAV_SPEED. If you are using CH6 for WPNAV_SPEED setting from your RC radio, check that your CH6 receiver failsafe is set to a correct value or you could get a very slow RTL during a radio failsafe event.

Warning: In RTL mode the fl ight controller uses a barometer which measures air pressure as the primary means for determining altitude (“Pressure Altitude”) and if the air pressure is changing in your flight area, the copter will follow the air pressure change rather than actual alti tude (unless you are within 20 feet of the ground and have SONAR installed and enabled).
Options (User Defined Parameters

 RTL_ALT: The minimum altitude the copter will move to before returning to launch.

 Set to zero to return at the current altitude.

 The r eturn altitude can be set from 1 to 8000 centimeters.

 The default return altitude Default is 15 meters (1500)

 RTL_ALT_FINAL: The altitude the copter will move to at the final stage of “Returning to Launch” or after completing a Mission.

 Set to zero to auto matically land the copter.

 The final return altitude may be adjusted from 0 to 1000 centimeters.

 RTL_LOIT_TIME: Time in milliseconds to loiter above the “Home” position before beginning final descent.

 The “Loiter” time may be adjusted from 0 to 60,000 mill iseconds.

 WP_YAW_BEHAVIOR: Sets how the autopilot controls the “Yaw” during Missions and RTL.

 0 = Never change Yaw.

 1 = Face Next Waypoint or for RTL face nose in (towards Home).

 2 = Face Next Waypoint or for RTL face nose out (away from Home).

 LAND_SPEED: The descent speed for the final stage of landing in centimeters per second.

 The landing speed is adjustable from 20 to 200 centimeters per second.

Notes

 Other navigation settings also have an influence over RTL mode:

 WPNAV_ACCEL

 WPNAV_LOITER_SPEED

 WPNAV_S PEED_DN

 WPNAV_SPEED_UP

 To use RTL, GPS lock needs to be achieved (Blue GPS LED and Blue APM LED on solid not blinking) before arming and takeoff to establish the home or launch position.

 Note on the UBLOX GPS module the LED is off while acquiring satellite s and on blinking when satellites have been acquired.

 Landing and re

- arming the copter will reset home, which is a great feature for flying at airfields.

 If you get lock for the first time while flying, your home will be set at the location of lock.

 If you set the ALT_HOLD_RTL to a number at other than 0 it will go to and maintain that altitude while returning.

 RTL uses the waypoint_speed to determine how fast it travels.Page | 41

 Once the copter arrives at the home location the copter will enter Loiter mode, timeou t (AUTO_LAND), and then land.

 To prevent auto

- landing, simply change modes with the control switch to clear the landing timer and resume normal flight.

 The throttle stick controls the altitude while returning or loitering above home and not the motors dire ctly.Page | 42



### Auto Mode In autonomous (auto) mode, the copter will follow a pre

- programmed mission script stored by the autopilot, including autonomously navigated waypoints, commands, and events. This pages provides information for using auto mode. For informat ion on creating a mission script, visit the Planning a mission with waypoints and events page for detailed information on setting up a flight plan.

Overview Auto mode allows the copter to follow internal mission scripting to control its actions. Mission scripts can be a set of waypoints or very complex actions such as, takeoff, spin X times, take a picture, etc.

Since mission scripts depend on the GPS for location information, auto mode is GPS dependent and it is necessary to allow the GPS to achieve lock before arming and taking off. Always ensure that the LEDs on the autopilot and GPS module indicate that G PS lock has been acquired:

 Blue LED on APM is solid.

 Blue LED on GPS module is solid.

 Blue LED on GPS+Compass module is blinking.Page | 43

Warning: In Auto Mode the flight controller uses a barometer which measures air pressure as the primary means for determining altitude (“Pressure Altitude”) and if the air pressure is changing in your flight area, the copter will follow the air pressure change rather than actual altitude (unless you are within 20 feet of the ground and have SONAR installed and enabled).
Using Aut o Mode from Ground and from the Air There are two ways to enter auto mode: in the air or on the ground. If you are going to use auto mode to take off from the ground, a special safety prevents the execution of the mission script until you both arm and then raise the throttle for the first time. This is to prevent your copter from taking off on its own by accidentally flipping the mode switch. When using auto mode to takeoff from the ground, your most recent Alt_hold throttle value is used as a baseline for throttle control. Once the copter has taken off it will proceed to the first target altitude and to begin following the mission script.
Switching to auto mode when you are already in the air will cause your copter to go to your first target altitude and to begin following the current mission script.
Ending a Mission Once the mission script is complete, the copter will not fly home, it will simply loiter at the last script location until you regain control through the mode switch. If you want your copter to fly home you can add an RTL command to the end of your mission script. If you want to land manually and disarm the motors (rather than auto land with a pre

- programmed command), you must switch into stabilize mode to do so.
Remember that when using RTL, the copter will return to the home position (the location of the copter at the time of arming after the GPS is locked), so it is very important to arm your copter in the location you want it to return (unobstructed and away from people) when using auto mode

. Warning: It is important to understand the home position always refers to the physical location where your copter was armed !
RTL or auto land at the last location in the mission script will force landing and disabling of the motors. Unless one of these two options is configured, you cannot land manually in auto mode, since the throttle stick controls altitude, not the motors directly.
Tuning

 The Waypoint_Speed value sets the rate of travel between waypoints.

 The default speed between waypoints is 6 meters p er second by default.

 The NAV_PI is used to maintain the desired rate of travel for your copter between waypoints.

 NAV_P is used to tilt the copter to achieve the desired rate of speed, be it fast or no speed at all.

 The higher the P the more the copter wi ll tilt.

 Nav_I is used to compensate for outside forces that would make your copter not maintain the desired rate.

 A high I term will ramp quickly to hold the desired rate, and will ramp down quickly to avoid overshoot.Page | 44



### Guided Mode Guided mode is a capability of APM: Copter to dynamically guide the copter to a target location wirelessly using a telemetry radio module and ground station application. This page provides instructions for using guided mode.

Overview Guided mode is not a traditional flight mode that would be assigned to a mode switch like other flight modes. The guided mode capability is enabled using a ground station application (such as Mission Planner) and telemetry radio (such as the 3DR Telemetry Radio). This capabili ty allows you to interactively command the copter to travel to a target location by clicking on a point on the Mission Planner Flight Data map. Once the location is reached, the copter will hover at that location, waiting for the next target. Follow Me mod e also uses Guided Mode to make the copter follow the pilot around the field.Page | 45

What you’ll Need To use guided mode, you’ll need a telemetry device like the 3DR Telemetry Kit 915mhz (US) or 433mhz (Europe) allowing your computer and autopilot to communicate during flight, a ground station computer or tablet, and a ground station application such as Mission Planner

.
Instructions

 Set up your copter at the field and establish a MAVLink connection over wireless telemetry between your copter and y our laptop.

 On your laptop, using the software that came with the telemetry module, make sure that it’s working and that you have a GPS lock.

 Take off in Stabilize mode and once at a reasonable altitude, switch to Loiter.

 In the Mission Planner Flight Data screen map, try right

- clicking on a nearby spot and select “Fly to Here”.

 You will be asked for a guided mode altitude. Enter an above home altitude in meters.

 A “Guided” target should appear on the map and the orange line (which indicates the target hea ding) should point to this guided target.Page | 46

 The vehicle should fly to the target location and wait there until you enter another location or switch to another mode.
Note: There’s no need to set up one of your flight modes as “Guided”Page | 47



## Board LEDs and Soun ds
APM 2.5/2.6

LED Behavior: Power On When Powered A ( Red )  Solid = armed, motors will spin when throttle is raised

.

 Single Blink = disarmed, motors will not spin

.

 Double Blink = disarmed, motors will not spin, cannot arm because of failure in pre

- arm checks B (Yellow) Only flashes along with A and B during calibration or as part of the in

- flight auto trim

feature C (Blue)  Solid = GPS working, 3D lock

 Blinking = GPS working, no

 Lock

- OFF = GPS not attached or not working PPM/Serial Flashing when data detected
3DR GPS+Compass Module The 3DR GPS+Compass module has two LED indicators: one for power (solid red) and one for GPS lock (flashing blue).

LEDs: Behavior: Power Solid Red when powered GPS lock Flashing Blue when 3D lock acquiredPage | 48



## Pre

- Arm Safety Checks(PASC) APM: Copter 3.0.1 (and higher) includes a Pre

- arm Safety Check which will prevent your Copter from arming if any of the following issues are present.

1. Verifies that Radio Calibration has been performed. 2. Verifies that Accelerometer Calibr ation has been performed. 3. Verifies that the Compass is Healthy and communicating properly. 4. Verifies that Compass Offsets are not too large : (greater than

- 150 and less than 150). 5. Verifies that the Compass Live or Log based calibration has been performed or that “COMPASS_LEARN” is on. 6. Verifies Adequate Compass Magnetic Field Strength: (APM 2 = about 330, APM1 = about 530, PX4 = about ?) 7. Verifies that the Barometer is Healthy and communicating properly. 8. If Geo

- fencing is enabled the safety check verifies tha t you have GPS Lock before it will allow you
to arm. 9. Verifies that the flight controller board Voltage is between 4.5 and 5.5 volts for APM 1 or APM 2 (Disabled on PX4) 10. Verifies that Channel 7 and Channel 8 are Not set to control the same thing.
If everyth ing else seems OK except that when you try to Arm with the throttle down and to the right, it will not actually arm and the motors will not spin, it has probably failed the Pre

- Arm Safety Check. You should also notice that the red arming light will doubl e flash.



### To See what has caused the PASC Failure
1. Connect your Flight Controller to Your Computer via the USB port. 2. Start Mission Planner and select the “Connect” button on the upper right of the page. 3. Turn on your radio transmitter and hold your throttle d own and to the right (normal arming procedure). 4. The first cause of the Pre

- Arm Safety Check failure will be displayed in red on the HUD window. 5. Address and correct each problem that is reported when you attempt to arm as above. 6. When all problems have been corrected, you will see verification of “Arming” in the HUD window. 7. You can then disconnect from your computer and have good assurance that arming will proceed normally.Page | 49



### Fixing Specific PASC Failures
1. If Radio Calibration check fails: Go to Mission Planner

– Configuration

– Radio Calibration.

a. And execute the Radio Calibration Procedure. 2. If Accelerometer Calibration check fails: Go to Mission Planner

– Configuration

– Ardu

- Copter Level.

a. Select your frame type and select the “Calibrate Accel” button and perfor m the leveling procedure. 3. If there is a Compass failure, you can go to Mission Planner

– Configuration

– Hardware Options

– Compass.

a. And select the Live Calibration button. 4. Alternatively for a compass problem, Go to Mission Planner

– Configuration

– Advanced Params

– Adv Param List.

a. Scroll down to the “COMPASS_LEARN” parameter, type in a 1 to enable it and select “Save Parameters”. 5. If the Barometer check fails: You have a har dware problem with the barometer or the flight controller board.

a. If the Geo

- fencing without GPS Lock check fails, wait for your GPS to acquire lock before attempting to arm. 6. Or you can go to Mission Planner

– Configuration

– Geo

- fencing and clear the Enabl e Geo

- fence box (turn it off).

a. If the battery voltage check fails, you are either supplying too high or too low a voltage to the APM board. 7. Or your peripherals that are being powered by the APM have too high a current draw.

a. It is very important to correct this problem and ensure you have between 4.5 and 5.5 volts at your APM board. 8. If Channel 7 was set to the same thing as Channel 8, one of them must be set to another option.Page | 50



## Arming and Disarming the System
Arming the Motors Before arming the motors, make sure all people and objects are clear of the propellers. Then do the following:

1. Turn on your transmitter 2. Plug in your LiPo battery. The red and blue lights should flash for a few seconds as the gyros are calibrated (do not move the copter) 3. If the red arm ing light is double blinking then the copter has failed the pre

- arm checks. Please refer to this page

. 4. Check that your flight mode switch is set to Stabilize or ACRO 5. If using a PX4, press the safety button until the light goes solid. 6. If you are planning on using the autopilot you should wait for 30 seconds after the blue GPS light has gone solid. This additional 30 seconds will give your GP S position time to settle. 7. Arm the motors by holding the throttle down, and rudder right for 5 seconds. It takes approximately 5 seconds the first time the copter is armed as it initializes the barometer. Do not hold the rudder right for too long (>15 se conds) or you will begin the AutoTrim feature. 8. Once armed, the red arming light should go solid. 9. Raise the throttle to take

- off.
Note: you can only arm or disarm in Stabilize o r ACRO mode
Note: if you leave the throttle at minimum for 30 seconds while in Stabilize or ACRO mode the motors will automatically disarm. 

### Disarming the Motors To disarm the motors do the following:

1. Check that your flight mode switch is set to Stabilize or ACRO 2. Hold throttle at minimum and rudder to the left for 2 seconds 3. The red arming light should start flashing 4. If using a PX4, press the safety button until the led begins flashing 5. Disconnect the LiPo battery 6. Turn off your transmitterPage | 51



## Rate Roll and Pit ch P Tuning Although there are many gains that can be tuned in APM: Copter to get optimal performance but the most critical is the Rate Roll and Pitch P values. This page covers how to tune this gain during your maiden flight. This alone will likely get it flying reasonably well at least in Stabilize mode.
Rate Roll P and Rate Pitch P can be tuned in flight using your transmitter’s channel 6 tuning knob by following these instructions:

1. Connect your APM/PX4 to the Mission Planner 2. On the mission planner, s elect Software > A r du

- Copter Pids 3. Set the CH6 Opt to “Rate Roll/Pitch kP”
4. Set Min to 0.08, Max to 0.20 (most copters ideal gain is within this range although from a small number of copter the Max can be as high as 0.25) 5. Push the “Write Params” button 6. Turn your transmitter’s CH6 tuning knob to the minimum position, press the “Refresh Params” button and ensure that the Rate Roll P and Rate Pitch P values become 0.08 (or something very close)
7. Turn the CH6 knob to its maximum position, press “Refresh Params” an d ensure the Rate Roll P moves to 0.20 8. Move the CH6 knob back to the middle 9. Arm and fly your copter in Stabilize mode adjusting the ch6 knob until you get a copter that is responsive but not wobbly 10. After the flight, disconnect your LiPo battery and reconne ct the APM to the mission planner 11. With the CH6 knob in the position that gave the best performance, return to the Ardu

Copter Pids screen and push the “Refresh Params” button 12. In the Rate Roll P and Rate Pitch P fields re

- type the value that you see but jus t slightly modified so that the mission planner recognizes that it’s changed and resends to the APM/PX4 (Note: if you re

- type exactly the same number as what appears in Rate Roll P it won’t be updated). So for example if the Rate Roll P appears as “0.1213 ′′ make it “0.1200′′ 13. Set Ch6 Opt back to “None” and push “Write Params” 14. Push the Disconnect button on the top right, and the Connect 15. Ensure that the Rate Roll P value is the value that you retyped in step #12Page | 52

Note: while you are moving the tuning knob the values update at 3 times per second. The need to press the Refresh button in the mission planner in steps #6 and #7 above is just because the APM: Copter is not sending the updates to the mission planner in r eal

- time.Page | 53



## Measuring Vibration For good altitude hold and loiter performance it is important that your vibration levels are low. The instructions below will shows you how to measure the vibration levels. If you find they are out

- of

tolerance you should follow the advice found on the First Time Set

- up sections Vibration

. Please follow these steps to ensure your vibration levels are within tolerance:

 Connect your APM/PX4 to the mission planner

 Go to the CONFIG/TUNING > Advanced Params screen and set the Lo g bitmask to Default+IMU. This will enable the capture of the accelerometer data to the dataflash logs.

 Press the “Write Params” button

 Fly your copter in Stabilize mode and try to maintain a level hover (it doesn’t need to be perfectly stable or level)

 Disconnect the LiPo , reconnect your APM/PX4 to the mission planner

 Download the latest dataflash log using the TerminalPage | 54

 When the Log Browser appears, scroll down until you find any IMU message. Click on the row’s AccX and push “Graph this data Left” b utton. Repeat for the AccY and AccZ columns to produce a graph like below.

 Check the scale on the left and ensure that your vibration levels for the AccX and AccY are between

- 3 and +3. For AccZ the acceptable range is

- 15 to

- 5. If it is very close or over these limits you should refer back to the 

### Vibration Dampening page for possible solutions.Page | 55

 After all the above is complete, go back to the Mission Planner’s advanced parameters page (you may need to press the “Connect” button again) and set the Log Bitmask back to “Default”. This is important because especially on the APM logging requires significant CPU resources and it’s a waste to log these if they’re not really needed.Page | 56



## Save Trim and Auto Trim Wind of course has a strong effect on your copter and will push it around. However you may also find that while flying in stabilize mode, even in a windless environment your copter tends to always drift away in the same direction. This can largely be corrected using the “Save Trim” or “Automatic Trim” functions.



### Save Trim Save trim is the simpler method and involves essentially transferring your radio transmitter’s trims to the APM ( video demo here ).

1. Check that your CH7 switch goes above 1800 on the Mission Planner’s Hardware > Mandatory Hardware > Radio Calibration screen.

2. Set the CH7 Option to Save Trim on the Software > Ardu

- Copter Pids screen and press the “Write Params” button.Page | 57

3. With your CH7 switch in the off position, fly your copter in Stabilize mode and use your transmitters’ roll and pitch trim to get it flying level. 4. Land and put your throttle to zero 5. Release the roll and pitch sticks and switch the CH7 switch high for at least 1 second. 6. Reset your transmitters roll and pitch trims back to the center and fly again and it should fly level now. If it does not repeat steps 3, 4 & 5.



### Auto Trim With auto trim the roll and pitch trim are captured as you fly in a stable hover.

1. Find a wind free environment with sufficient space to fly your copter without crashing into something. 2. Hold throttle down and rudder right for 15seconds or until you see the small red, blue and yellow LEDs flash in a cyclic pattern. 3. Fly your copter for about 25 seconds in a stable hover 4. Land and put your throttle to zero and wait for a few seconds (the trims are being saved to eeprom) 5. Take off again in stabilize mode and check if your copter is flying level now. If not repeat steps 2, 3 and 4.
Note: you can also test these procedures above are operational on the ground with your battery disconnected. Connect your APM to the mission planner and observing the Flight Data screen as you simulate completing the s teps above.Page | 58



### Note2: you can manual set the trim through the mission planner’s Adv Parameters List page. Roll trim is AHRS_TRIM_X, Pitch trim is AHRS_TRIM_Y. Both values are in radians with left roll and forward pitch being negative numbers.

Note3: it’s n early impossible to get rid of all drift so that your copter remains completely motionless without any input.Page | 59



## Flight Test Process

To Test Loiter and Altitude Hold:
1. Set up your APM so that Stabilize mode is at one extreme of your three

- position mode selec t switch on your RC transmitter, Alt Hold mode is in the middle and Loiter mode is in the third position. 2. First, it ́s important that Stabilize Mode is working OK. Set the Mode switch to Stabilize, turn on the transmitter and connect your battery. Wait unti l the GPS gets a lock. (Both the Blue GPS LED and the Blue C LED on the APM should be on and solid before arming and taking off). (It is even better to wait a bit longer to allow the GPS acquire additional satellites.) Note! The UBLOX GPS works differently On the UBLOX GPS the LED on the GPS module is off during satellite acquisition and on with the blue LED blinking when the satellite is acquired. 3. Hold the throttle down and to the right for several seconds to “Arm” The motors on your copter. 4. Start flying in Stabilize mode. Make sure you can take off, fly comfortably, and land. If you find it tilting, land and run the “Level” command in the Mission Planner. Fly through a whole battery like this, getting a feel for the controls (this will also calibrate your compass). 5. Now change batteries and try the auto modes. First, try Alt Hold at an altitude of about 20 meters. Your actual current throttle position is recorded as the “hovering point” when you switch to an altitude holding mode so it is important that you are not ascending or descending when you switch to Alt Hold. You should be able to fly around with the copter maintaining the same altitude, plus or minus a meter or so. 6. If that’s working well, try Loiter. Just fly to a safe spot with lots of room around it and an altitude of about 20 meters and switch into Loiter. It should try to stay in that position, plus or minus about five meters. 7. When you have finished flying in Loiter or Alt Hold modes (or if anything unexpected or undesirable happens) switch back to Stabilize mode and land. (You cannot land and turn the motors off in Loiter or Alt Hold mode.) 8. Disarm your copter and record a log by holding the throttle down and to the left for 5 seconds. 

### What to Expect? In Alt Hold, the copter should stay at the alt itude you initiated the mode in, give or take about a meter. Adding sonar will improve that to +

- 20cm accuracy up to 12 feet of altitude

. ( Above which sonar doesn’t work).

Warning: The flight controller uses a barometer which measures air pressure as the primary means for determining altitude (“Pressure Altitude”) and if the air pressure is changing in your flight area, the copter will follow the air pressure change rather than actual altitude.Page | 60

In Loiter, the quad should stay in a 4

- 5 meter diameter “circl e” around the target position. If there is wind, it may take a few seconds to compensate. If the wind is strong, you may see the control can’t compensate and you will have more error (ex 10

- 15 meters).
You can use the stick to move the quad manually in Loi ter. Or you can use the throttle to raise or lower the quad.

 Warning: “Home” position is always supposed to be your Copters actual GPS takeoff location:

 It is very important to acquire GPS lock before arming in order for RTL, Loiter, Auto or any GPS depend ent mode to work properly.

 For APM: Copter if you get GPS lock and then ARM your copter the home position is the location the copter was in when it was armed.

 This means if you execute an RTL in APM: Copter , it will return to the location where it was

arme d.

 For APM: Copter : Arm it where you want it to return to: (Not the Pits).Page | 61



## Advanced Configuration and Tuning This section will take you through the more advanced configuration and tuning options for APM: Copter

Compass Set

- up (Advanced)

– all the compass set

- up procedures explained

Fail

- safe

– protection for loss of radio contact, low battery, loss of GPS lock, loss of contact with the ground station

Fence

– protection against fly

- always

PPM Encoder information

 General information on the PPM Encoder

 Updating your APM’s PPM Encoder firmware

– important if you purchase your APM before Mar 2013

 Updating your APM’s PPM Encoder firmware (2)

– same information as above

 Using the stand

- alone PPM Encoder
Ch7 & Ch8 Auxiliary Functions

– features that can be inv oked from the Ch7 and Ch8 switches

Tuning

– main tuning guide for APM: Copter

 Attitude Tuning (i.e. mo re details on Roll and Pitch Tuning)

 Altitude Hold Tuning

 Loiter and Nav igation Tuning

APM: Copter parameters:

 Full parameter list

 Standard paramete r list
Command Line Interface (CLI)

– for those who don’t like graphical user interfaces

 CLI for radio and flight mode setup, test overview

 CLI for testing radio input

 CLI for dumping contents of eeprom
Testing your APM’s accelerometer and gyro sensors

Don e all the above? Then you’re ready for Mission Planning and Analysis !Page | 62



## Compass Setup This page covers all the possible compass set

- up procedures in detail inc luding some rarely used options.
Users must perform the first item ( Live Calibration ) and it’s strongly recommended that they perform the 2nd ( Compassmot ) as well to achieve good compass performance which is required for Loiter, RTL and AUTO flight modes.
If you after performing the above steps (and after trying to move your APM/PX4 further from source of compass interference) you still experience circling (also known as “ toilet bowling ”) in Loiter then you may wish to attempt the 3rd option ( Tuning Declination In

- Flight ).
It is not recommended that users try the 4th ( Automatic Learning of offsets during flight ) and 5th ( Log based calibration of offsets ) options. The 6th item ( Manually entering Declination ) is also rarely significantly better than the automatically calculated declination.



### Live Calibration of compass offsets This is the default method for calculating offsets:

 Connect the APM to the mission planner

 Go to the hardware > Mandatory Hardware > Compass screen

 Push the “Live calibration” button

 When the screen below appears, select OK and you will have 60 sec. to complete the process.

 During the 60 sec. you should hold the copter in the air and rotate it slowly so that each side (front, back, left, right, top, and bottom) points down toward the earth for a few sec. in turn

.Page | 63

 A countdown will be displayed while it’s collecting data and, upon completion, the new offsets will be displayed. As long as all three values are between

- 150 and 150 the offsets are good. 

### Compassmot

- compensation for interference from the PDB, ESC, or mot ors This “ Compassmot ” set

- up helps compensate for interference on the compass from the power

distribution

- board (and wires), ESC, motors and batteries. Please follow these instructions:

 Enable the 3DR power module or Non

- 3dr current monitor if present. If present this will allow more accurate compensation because the interference is linear with current drawn but not perfectly linear with throttle.

 Disconnect your props, flip them over and rotate them one position around the frame. In this configuration the y should push the copter down into the ground when the throttle is raised

 Secure the copter (perhaps with tape) so that it does not move

 Turn on your transmitter

 Connect your vehicle’s LiPo battery

 Connect your APM/PX4 to your computer with the usb cable

 O pen the mission planner’s terminal screen, press the “Connect APM” or “Connect PX4′′ button

 At the prompt type setup and then Compassmot

.

 If you have a Power Module/Current monitor enabled you should see “measuring compass vs. CURRENT” otherwise you will s ee “measuring compass vs. THROTTLE”Page | 64

 You should hear your ESCs arming beep

 Raise the throttle slowly to between 50% ~ 75% (the props will spin!) for 5 ~ 10 seconds

 Quickly bring the throttle back down to zero

 Press enter to complete the calibration

 Check th e % of interference displayed. If it is less than 30% then your compass interference is acceptable and you should see good Loiter, RTL and AUTO performance. If it is 31% ~ 60% then the interference is in the “grey zone” where it may be ok (some users are fine, some are not). If it is higher than 60% you should try moving your APM/PX further up and away from the sources of interference or consider purchasing an external c ompass or GPS+compass module. 

### Tuning Declination in

- flight Instead of using the automatic declination you can tune your declination value in flight using the Channel 6 tuning knob on your transmitter by following these steps:

1. Connect your APM/PX4 to the Mission Planner 2. Go to the Software > Ardu

- Copter Pids screen 3. Set the Ch6 Opt to “Declination”, Min to “0.0′′ and Max to “3.0′′. This will give a tunable range of

- 30 to +30 degrees. Set Max to “2.0′′ to tune from

- 20 to +20 degrees, etc.

 Check that the declination is being tune correctly by turning the channel 6 tuning knob to its maximum position, go to the Software > Adv Parameters List screen, press the “Refresh Params” bu tton and ensuring that COMPASS_DEC is 0.523 (this is 30 degrees expressed in radians)Page | 65

 Fly your copter in Loiter mode in at least two directions and ensure that after a fast forward flight you do not see any circling (also known as “toilet bowling”).

 If you find it’s impossible to tune away the circling then it’s likely your compass interference is will require an external
compass or GPS+compass module. 

### Automatic learning of offsets during flight APM: Copter (and Plane and Rover) include the ability to learn the offsets slowly during flight instead of performing the Live Calibration mentioned abo ve. While this method works well on APM:

- Plane it generally cannot deal with the high interference levels on many copters and has been known to slowly calculate extremely large offsets (less than

- 150 or greater than 150) which leads to incorrect heading and the copter flying off in the wrong direction in RTL, Loiter, AUTO.
It can be enabled by doing the following:

 Connect the APM/PX to the mission planner

 Go to Software > Advanced Params, scroll down to “Learn compass offsets automatically (COMPASS_LEARN )” and set it to “Enabled”

 Press the Write Params button



### Log based calibration of offsets This option is very close to the “Automatic learning” method (see above) except that a flight log is used instead of performing the calibration during an actual fligh t. This method suffers the same issue in which , due to high interference from the PDB, motors, etc the calculated offsets can be out of tolerance (i.e. less than

- 150 or greater than +150).Page | 66

For this process you will need to fly the vehicle (any flight mo de is acceptable) for at least a few minutes and most importantly the copter should be faced in all four directions (internally the algorithm divides the data up into 8 quadrants and it will fail if it doesn’t have any data from some quadrants)

The method can be done as follows:

 Connect the APM/PX4 to the mission planner

 Go to Hardware > Mandatory Hardware > Compass and click the “Log Calibration” button

 When the “Min Throttle” box pops up leave the number as the default 30

 If a message pops up saying “Log does not contain enough data” you will need to find another log in which you’ve flown longer and have flown the copter in more directions

 If the process completes successfully a “New Mag Offsets” box will pop

- up with the new calculated offsets. As long a s these are greater than

- 150 and less than +150 it has likely done a good job. 

### Manually entering declination By default APM: Copter will look up the declination in a compressed table when it first achieves GPS lock. In generally this method is accurate to within 1 degree but if you wish to use the uncompressed declination value you can do this:

 Open the Declination Website

.

 It should automatically figure out your location based on you IP address or you can enter your location

 Uncheck the Auto Dec checkbox and manually enter the declination (highlighted in red i n the image above) into the mission planner’s declination field. In this example, we would enter “14.13′′ into the magnetometer line

 As soon as your cursor exits the field (i.e by pressing Tab) the value will be converted to decimal and saved to the eepromPage | 67Page | 68



## Fail

- safes As of version 3.0, APM: Copter has four fail

- safe : Throttle, Battery, GPS and Ground Station Control.
Only the GPS failsafe is enabled by default.



### Throttle Fail

- safe If enabled and set

- up correctly the throttle failsafe will trigger if:

 Yo ur copter goes out of radio range.

 You turn off your transmitter.

 Your receiver loses power for some reason.

 The channel 3 signal wire from your receiver to your APM’s input becomes disconnected.
Note: This behavior depends upon the version of your ppm en coder. Instructions for updating your ppm encoder firmware are here for APM2.X

.

 The APM’s PPM encoder fails to send updates for 2 seconds (very unlikely). The PPM encoder is a small chip on the APM boards whose sole function is to read the radio signals from the receiver and send them to the APM’s main CPU.

When a throttle failsafe is triggered one of the following will happen:

 Disarm motors

– if you are in stabilize or acro m ode and your throttle is zero

 RTL

– if you have a GPS lock and are at least 2 meters from your home position

 LAND

– if you have no GPS lock or are within 2 meters of home when the failsafe triggersPage | 69

 Continue with the mission

– if you are in AUTO mode and ha ve set the Failsafe Options to “Enabled_continue_in_auto_mode”.

 If the failsafe clears (throttle climbs back above 975) the copter will remain in its current flight mode. It will not automatically return to the flight mode that was active before the failsa fe was triggered. This means that if, for example, you are flying in stabilize mode when the failsafe is triggered, and this causes the flight mode to change to RTL or LAND, if you wish to re

- take control of the copter you will need to change your flight m ode switch to another position and then back again to Stabilize.



### Throttle Fail

- Safe Setup

Receiver set

- up:

 Each brand of Transmitter/Receiver has a slightly different method of setting up its failsafe but all but the very cheapest brands allow you to set the levels that you want some or all of the channels to move to when the transmitter and receiver (tx/rx) lose contact. Please refer to your transmitter’s user manual for details on how to en able the failsafe. Below are links for specific transmitters/ receivers :

 Futaba T7C TX with R617FS or TFR4

- B receiver

 You must set

- up the throttle channel (channel 3) to move below its no rmal range (ideally below 975) when the transmitter is turned off and ideally all other channels should remain at their last position or move to the middle

 To see what level your throttle channel becomes when the tx/rx lose connect your APM to the Mission Planner and check the levels on the Software > Failsafe page.
APM Setup With the LiPo battery disconnected, connect your APM to the mission planner and select Software > Failsafe.
Set the Failsafe Options to “Enabled_always_RTL” or “Enabled_continue_in_aut o_mode” if you expect to do auto missions that will take your copter beyond tx/rx range (which is generally not recommended).
Adjust the FS Pwm field to be:

 at least 10 pwm higher than your Channel 3′s pwm value when your transmitter is off

 at least 10 lower than your channel 3′s pwm value when your transmitter is on

 above 910Page | 70



### Testing for correct operation of Throttle Fail

- safe You can check your failsafe by performing the following tests with the APM connected to your mission planner either via a USB cable or telemetry link. You can complete these tests without plugging in your LiPo battery but if you do connect a battery you should first remove the propellers.
Test #1 : ensuring that your throttle channel drops with loss of radio contact

1. Ens ure your RC transmitter is on and connected with the throttle all the way down and flight mode set to Stabilize 2. The throttle (channel 3) pwm value should be approximately as in first illustration below. It’s value may be higher or lower but it should defi nitely be at least 10 higher than the value held in the FS Pwm field 3. Turn the transmitter off and the throttle pwm value should drop to be at least 10 below the FS Pwm field value (as in the second illustration below) belo wPage | 71

Test #2 : ensuring motors disar m if in stabilize or acro with throttle at zero

 Switch to stabilize mode, arm your motors but keep your throttle at zero. Turn off your transmitter. The motors should disarm immediately (red led will start flashing, DISARMED will be displayed in the Missio n Planner’s Flight Data screen).
Test #3 : ensuring flight mode changes to RTL or LAND when throttle is above zero

 Switch to stabilize mode, arm your motors and raise your throttle to the midpoint . Turn off your transmitter. The Flight Mode should switch to RTL if you have a GPS lock or LAND if you do not have a GPS lock (the flight mode and GPS lock status are visible in the Mission Planner’s flight data screen).
Test #4 : retaking control after a throttle failsafe event

 continuing on from test #3, turn y our transmitter back on

 While the flight mode is still in RTL or LAND and armed, change the flight mode switch to another position and then back to stabilize mode. Ensure that the flight mode displayed on the Failsafe page is updating appropriately.

Test #5 (optional) : removing power from the receiver

 Switch to stabilize mode, arm your motors and keep your throttle above zero.

 carefully disconnect the power wires connecting the receiver to the APM

 the Flight Mode should switch to RTL or LAND as described in Test #3

 Warning: unplug the APM so that it is powered down before reattaching the receiver’s power
Warning to FRSky receiver users and users of other receivers that modify channel 5 during a failsafe
event
Some FRSky tx/rx systems receivers can only be set

- up to modify all channels including the flight mode channel (channel 5) when a failsafe event occurs. For these receivers it is important to setup the receiver’s channel 5 failsafe value so that the APM is switched into RTL, Loiter or LAND. This is c ritical because there is a very short period of time (3/50ths of a second) between when the receiver pulls the throttle low and when the APM initiates the RTL or LAND. During this time, if the receiver also switches the flight mode channel to stabilize or acro the APM may switch to stabilize momentarily and then because the copter is in stabilize with throttle at zero it will disarm the copter (i.e. Test #2). 

### Battery Fail

- safe

 If enabled and set

- up correctly the battery failsafe will trigger if:

 your battery voltage becomes low for more than 10 seconds

 your estimated current consumed passes your battery capacity (set on the power module set

- up page )

 When a battery failsafe is triggered one of the following will happen:

 Disarm motors

– if you are in stabilize or acro mode and your throttle is zeroPage | 72  RTL

– if you are in AUTO mode, have a GPS lock and are at least 2 meters from your home position

 LAND

– in all other cases

 Setting up the battery failsafe

 first set

- up the power module as described here including setting the Battery Capacity if using a current monitor

 On the INITIAL SETUP > Mandatory Hardware > Failsafe page click the Battery Failsafe checkbox and enter the Low Battery level that you wish to have trigger an RTL or LAND.



### GPS Fail

- safe

 The GPS Failsafe is enabled by default but you can enable or disable it on the Mission Planner’s Advanced Parameter List, by set the FS_GPS_ENABLE parameter to 0 (disable) or 1 (enable).

 If you lose GPS contact for 5 seconds while you are in AUTO, GUIDED, LOITER, RTL, CIRCLE or POSITION mode it will initiate a LAND.



### Ground Control Station Failsafe

 In Mission Planner’s Advanced Parameter List, set the FS_GCS_ENABLE parameter to:

 0 to disable the GCS failsafe

 1 to enable and always RTL in event of loss of contact

 2 to RTL unless in AUTO mode in which case we should continue with the mission

 If you have been using the ground station to control the copter (i.e. using a joystick) and then lose Ground Control Station contact for at least 5 seconds the following will happen:

 Disarm mo tors

– if you are in stabilize or acro mode and your throttle is zero

 RTL

– if you have a GPS lock and are more than 2 meters from your home positionPage | 73  LAND

– if you have no GPS lock or are within 2 meters of home

 Continue with the mission

– if you are in AU TO mode and have set the GCS Failsafe Options to 2 (Enabled_continue_in_auto_mode).

 If the failsafe clears (contact with the ground station is restored) the copter will remain in its current flight mode. It will not automatically return to the flight mode that was active before the failsafe was triggered. This means that if, for example, you are flying in stabilize mode when the failsafe is triggered, and this causes the flight mode to change to RTL or LAND, if you wish to re

take control of the copter you will need to set your flight mode again back to stabilize.Page | 74



## Geo

- Fencing

Overview AC 3.0.1 (and higher) include a simple “tin can” shaped fence centered on home that will attempt to stop your copter from flying too far away by initiating an RTL. The max imum circular distance and altitude and the vehicle behavior when the fence is reached can be configured using Mission Planner.

If the vehicle strays outside these borders it will switch into RTL or LAND. At the moment the fence is breached a backup fence is erected 20m further out (or up). If the copter breaches this backup fence (for example if the the vehicle is not set up correctly or the operator takes control but is unable to bring the copter back towards home) the copter will be switched into RTL a gain (and another backup fence an additional 20m further out will be created).
If the copter eventually flies 100m outside the configured fence distance, the vehicle will switch into LAND mode. The idea being that it’s clearly impossible to get the copter home so best to just bring it down. The pilot can still retake control of course with the flight mode switches. Like with the earlier fences, another fence is erected 20m out which will again switch the copter to LAND if it continues away from home.Page | 75



### Enabling the Fence in Mission Planner

The Fence can be set

- up by doing the following:

 Connect your APM/PX4 to the Mission Planner

 Go to the Software

- > GeoFence screen

 Click the “Enable” button

 Leave the “Type” as “Altitude and Circle” (unless you want only an Altitude limit or only a Circular fence in which case you can select “Altitude” or “Circle”)

 Leave the Action as “RTL or Land”

 Set “Max Alt” to the altitude limit you want (in meters)

 Set “Max Radius” to the maximum distance from home you want (in meters). This should normally be at least 50m 

### Enabling the fence with Channel 7 or 8 It is not necessary to set

- up a switch to enable or disable the fence but if you wish to control the fence with a switch please follow these steps:

 Go to the Mission Plan ner’s Software > Ardu

- Copter Pids screen and set either “Ch7 Opt” OR “Ch8 Opt” to Fence.

 Holding the switch high (i.e. PWM > 1800) will enable the fence; low (less than 1800) will disable the fence.Page | 76

Warnings:

 The minimum recommended fence radius is 30m

 For the best results, ensure RTL is working on your vehicle.

 With the Fence enabled, the pre

- arm checks will require you have GPS lock before arming the vehicle.

 If GPS failsafe is not enabled and the Fence is enabled and you lose GPS lock while flying the fence will be disabled.

 If GPS failsafe is enabled and the Fence is enabled and you lose GPS lock while flying the vehicle will switch to LAND because we no longer know the vehicle position and we want to ensure the copter never travels far outside the fe nce. This behavior will occur regardless of the flight mode. If a LAND sequence is not desired, the pilot can retake control by moving the flight mode switch.

 The backup fences are created 20m out from the previous breached fence not 20m out from the veh icle’s position. This means if you choose to override the fence you may have less than 20m to regain vehicle control before the fence switches the copter to RTL (or LAND) again. If you really want to override the fence, you should be ready to switch the flight mode twice or alternatively set

- up the enable/disable fence switch.Page | 77



## Setting Channel 6, 7, or 8 options By default, Channel 7 is configured to save the current location as a waypoint (see “Save WP” below) but you can change the default behavior fr om the Mission Planner’s Software > Ardu Copter Pids screen.Page | 78

Here are the options: Option Description Flip Vehicle will flip is on roll axis. Vehicle will rise for 1 second and then rapidly

roll. The vehicle will not flip again until the switch is brought low and back to high. Give yourself at least 10m of altitude before trying flip for the first time! Simple Mode The copter moves left, right, forward and back as if it were facing in the same

direction as when it took off regardless of the copter’ s heading. RTL Return

- to

- Launch. The vehicle will first climb to a safe altitude (defined by

RTL_ALT parameter), then return home, pause over home for 5 seconds (configurable by RTL_LOIT_TIME parameter) then descend to 2m or land (configurable by RTL_ALT_ FINAL parameter). Save Trim Adjust the vehicle level position using the current roll and pitch stick inputs. See

details

. Save WP Save the current location (including altitude) as a waypoint in the mission. If in

AUTO mode no waypoint will be saved, instead the vehicle will RTL Multi Mode Ch6 tuning knob position controls which of the following 3 functions is invoked

when ch7 or ch8 switch put in the on position.

 Ch6 <1200 : Flip

 Ch6 1201 ~ 1799 : RTL

 Ch6 > 1800 : Save Waypoint Camera Trigger Camera shutter will be activated. See more details Sonar Sonar is disabled when switch is in low position, enabled when it high position. Fence Fence is disabled when switch is in low position, enabled when it high position. Reset to Armed Yaw Vehicle will turn to face the same direction that it was facing when it was first

armed (e.g. at take

- off). An alternative to simple mode when you’ve lost orientation and need to bring the craft home. Super Simple Mode Similar to simple mode except controls are relat ive home position. Move the

pitch stick forward and the copter will fly away from home, pull pitch back and it will return. Move roll stick left or right and the copter to orbit home regardless of the copter’s actual heading.


### Check Ch7 & Ch8 PWM values re ach 1800 Your channel 7 and/or channel 8 pwm values must reach at least 1800 PWM or the auxiliary function will not be activated. You can check that it surpasses this threshold using the Mission Planner’s radio config uration
page.Page | 79



## Tuning If you’re usin g an airframe other than the 3DR Copter kit, you may need to change some PID settings (PID stands for Proportional

- Integral

- Derivative and is a standard control method)
You can adjust PIDs interactively in the Mission Planner’s Configuration tab. Start wi th the APM: Copter PIDs page, which breaks out the most important settings and gives instructions on how to use them. More configuration settings can be found in the Standard Params and Advanced Params if you need them (you probably won’t).Page | 80



### Basic performance troubleshooting Remember two things:

 Start by using Stabilize Mode for tuning, if it doesn’t fly correctly in Stabilize it will NOT fly correctly in any of the other modes.

 First use the defaults. You shouldn’t have to deviate very far from the defaults that are loaded with the firmware, if you have to change them then use small increments and one at a time. If you have to use a value that is very different then either something else is wrong or your ‘copter is very different from everyone else’ s.
For normal flight, there is really only one term you should care about and that is the Rate Roll P setting (Rate Pitch is normally slaved to that, as the checkbox on the screen above shows). Use the in

- flight tuning method with CH6 to nail this term in a few seconds. Make it as aggressive as you can before it begins to oscillate. You will have great performance descending straight down if this term is higher. You may want to tune it down a hair more if you like a softer response.
Here’s an example: the default setting for Rate Roll P is 0.14. This is optimized for the standard Jdrones/3DR quad copter with 850 motors and a 10′′ prop. If, however, you’re using the bigger 880 motors and a 12′′ prop, which are much more powerful, that Ra te Roll P will be too aggressive and your quad will seem quite unstable. So in that case, lower your Rate Roll P to 0.1 or 0.09, and you should see much more stable flight.
The same is true for Altitude hold. Throttle Rate P needs to be adjusted to get opt imum altitude performance.
These two terms go a long way to making your copter perform well, and are highly dependent on the thrust to weight ratio of your copter. More thrust = lower gains.

 My copter oscillates quickly (smaller movements) when stabilized : Lower your gain in Rate Control P.

 My copter oscillates slowly (larger movements) when stabilized : Lower your gain in Stabilize Control P.

 My copter gets wobbly when descending quickly : Raise your gain in Rate Control P. You can tune most of this out, but it’s impossible to descend into your prop wash without some wobbles.

 My copter is too sluggish : Raise your Stabilize Control P gain. These gains make ask the copter to respond faster to angle errors.

 My copter yaws right or left 15° when I take off : Your Motors are not straight or your ESCs are not calibrated. Twist the motors until they are straight. Run the ESC calibration routine.

 My copter angles back in the opposite direction I’m flying after forward flight : Raise your gain in Stabilize Control P.Page | 81

 Af ter aggressive flying my copter leans to one side 10

– 30° : Do whatever you can to remove vibrations and isolate APM. You can even try and add a small weight to APM to keep it from vibrating. Also, just land for a few seconds, then continue flying, it will give APM a chance to correct without the vibration.

 My copter won’t stay perfectly still in the air : Run the level command on a flat surface. (hold disarm for 15 seconds to invoke.) You can also fly in auto

- trim mode in a windless (important!) environment . Any wind will cause the changes you make to work against you when the quad rotates 180°. You can use your radio pitch and roll trims, but remember to

re

- center them when you set up your radio with the config tools. Using the radio trims can have a negati ve effect in SIMPLE mode when yawing. Never Trim Yaw, Your copter may start spinning on its own. (Quads are also susceptible to drafts. They will need constant corrections unless you install an optical flow sensor. One day...)

 My copter flies well, but then dips a motor arm in a fidgety manner while hovering : Your motor may be going bad or the bullets connectors between the motor and ESC may be at fault. Vibration from a bent shaft or unbalanced props can make bullet connections fail momentarily stopping the motor. A motor with bad bearings takes more power to spin. The ESC could be cutting out to protect itself. Or it may be flying slow enough to stall the motor. Attach a current sensor between your battery and the motor and test the difference between a good motor and the bad one. If you are seeing higher draw in the bad one, replace or fix it.

 My copter suddenly crashed for no good reason : The I2C port, used to talk to the compass, has a rare but very serious flaw which will block code execution To avoid any issues be sure to solder the compass securely.

 In Loiter, my copter constantly overshoots : Try and increase your Nav_P term. You can also tune down your I terms because in some cases, the Nav_I or Loiter_I can causes overshoot. Making the I terms 0 when i n still wind is the best way to tune Nav_P.

 My alt hold above 10 feet is only about 1

- 2m accurate : That’s actually the best you can achieve. The baro sensor is sensitive to light and wind. Use a felt cover to protect it from wind and make sure you don’t gl ue the hole and seal it up.

 My copter increasingly swings up and down in alt hold . It eventually gets down to the ground: Your THROTTLE_P is too high or low. You don’t need a lot of P to do alt hold. Think of how much you move the throttle to hold alt perf ectly. Not much! That’s what you need P to do. I will ramp up as your battery goes lower to make up the difference.

 I have a sonar installed but I can’t get it to work . Your sonar may be picking up electrical noise from the ESCs. Be sure to move it a few i nches from any ESCs and try a shielded cable, if possible. If it’s cold outside, your sonar may stop working.

 My quad loiters by rotating in a CW or CCW circle : Adjust your compass declination until it stops circling.Page | 82



### In

- flight tuning You can tweak param eters in flight from Mission planner (needs a telemetry link or USB cable) or with the Transmitter (Tx) channel 6 knob or lever (You need an extra free channel that is controlled by a knob or slider on your transmitter(Tx) to use the CH6 fine

- tuning functi on, you can use any free channel on your Tx but it must be plugged in to the CH6 option on APM. So CHx on Tx > CH6 position on APM.)

Method 1: (See also Method 2: Flying Attitude Tuning below)

Select the “ APM: Copter Configuration” tab in the Mission Plann er, choose the CH6 option you’d like to tune. e.g. CH6_RATE_KP.
From MP v1.1.44 onwards these high and low values can be adjusted in boxes just below the CH6 options. Alternatively you can also adjust TUNE_HIGH and TUNE_LOW in the left hand pane of the Con figuration > Adv Parameter List.
Input the high and low limit of the parameter you’d like to tune, choose a value of + and

– around 30

- 40% of default, (so for CH6_RATE_KP set ‘low’ to 0.100 and ‘high’ to 0.180 from the default of 0.140)

Then click ‘Write P arams’. To check the values click ‘Refresh Params’, your high and low values should be correct in both the Parameter List tab (under TUNE_HIGH & TUNE_LOW) and in the adjustment boxes. If not enter them again.
To test that the values are changing: move the lever or knob then click ‘Refresh Params’, the value should be displayed in the center pane in the respective box, move it again and click ‘Refresh Params’ again, the value should’ve changed. Alternatively select the Terminal tab, type ‘test’ and then ‘tun e’ and your value will scroll down in the window, adjust the knob or lever to see the values change.
Now set your CH6 knob or lever to between 0 and 25% on your transmitter, then carefully test fly, land and tune the parameter with the knob or lever, test fly again.
To read your final parameter, leave the knob or lever on your Tx in your chosen position, connect to the MP then click ‘Refresh Params’, the value should be displayed in the in the respective box in the Parameter List tab (under TUNE_HIGH & TUNE _LOW). Alternatively select the Terminal tab again, type ‘test’ and then ‘tune’ and your value will scroll down in the window. Enter this value into the correct position in the Configuration tab.
Now tune another parameter or, if you’re finished, set the p arameter to CH6_NONE (important!)Page | 83

The main value to tune is your Rate_KP value. This value adjusts whether your copter is:

 no response to control inputs (too low)

 sluggish (a little too low)

 stable (just right)

 over

- active (a little too high)

 or oscillatin g (too high) 

### Here are all the parameters one can tune: CH6_NONE 0

— Attitude CH6_STABILIZE_KP 1 CH6_STABILIZE_KI 2 CH6_STABILIZE_KD 29 // duplicate with CH6_DAMP CH6_YAW_KP 3 CH6_YAW_KI 24

— Rate CH6_ACRO_KP 25 CH6_RATE_KP 4 CH6_RATE_KI 5 CH6_RATE_KD 21 CH6_ YAW_RATE_KP 6 CH6_YAW_RATE_KD 26

— Altitude rate controller CH6_THROTTLE_KP 7

— Extras CH6_TOP_BOTTOM_RATIO 8 CH6_RELAY 9

— Navigation CH6_TRAVERSE_SPEED 10 // maximum speed to next way point CH6_NAV_KP 11 CH6_LOITER_KP 12 CH6_LOITER_KI 27

— Trad Heli specific CH6_HELI_EXTERNAL_GYRO 13

— altitude controller CH6_THR_HOLD_KP 14 CH6_Z_GAIN 15 CH6_DAMP 16 // duplicate with CH6_YAW_RATE_KD

— optical flow controller CH6_OPTFLOW_KP 17Page | 84

CH6_OPTFLOW_KI 18 CH6_OPTFLOW_KD 19

CH6_NAV_I 20 CH6_LOITER_RATE_KP 22 CH6_LOITER_RATE _KI 28 CH6_LOITER_RATE_KD 23

CH6_AHRS_YAW_KP 30 

### Method 2: Flying Attitude Tuning with CH6: In this case you will tune your ‘copter while it is actually flying.
This assumes that the ‘copter is fairly flyable/controllable and that the pilot is experienced e nough to easily keep the ‘copter at eye level and in the same place for at least 60 secs. You will also preferably need an open space of perhaps 10mx10m (30ftx30ft).
Follow the setup in Method 1 above.
Do Rate_P first, choose a value of + and

– around 30%

- 40% of default, (so for Rate_P set ‘low’ to 0.100 and ‘high’ to 0.180 from the default of 0.140. Be careful not to set these values incorrectly

– don’t set 0.100 as 1.000 or 0.010!
Hover at about 1.5m (5ft) and bank the quad briefly left and right, then ei ther land and turn the knob/lever that controls the channel, or if you can fly and turn the knob/lever then do so, turn it up and down, note the difference and choose the flying style which “feels” best to you. Higher values might cause oscillations so bac k off a little until it flies without oscillations but isn’t too sluggish.
To read your final parameter, leave the knob or lever on your Tx in your chosen position, connect to the MP then click ‘Refresh Params’, the value should be displayed in the in the respective box in the Parameter List tab (under TUNE_HIGH & TUNE_LOW). Alternatively select the Terminal tab again, type ‘test’ and then ‘tune’ and your value will scroll down in the window. Enter this value into the correct position in the Configuration t ab.
Now tune another parameter or, if you’re finished, set the parameter to CH6_NONE (important!)
Note: (Set I values generally low, eg 0.000

- 0.100.) Interactive PID demos You can play with these Flash demos to get a feel for how PIDs work. Just click on t he arrows to change the values, or type in new ones. Click in the background of the left demo to have it read your space bar. In the Demo Stabilize P is out of date. We call it Rate_P now.Page | 85



## Attitude PID Tuning The attitude of the copter is controlled by a nested PI

- >PID loop. Tuning the inner PID loop is essential to good stable flight. The outer PI loop is less sensitive and effects mostly the style of flying desired (fast or slow).



### Overview The inner PID loop looks at the desired rate of angular rotation and compares that to the raw gyro output. The difference is feed back into the PID controller and sent to the motors to correct the rotation. This is the heart of both Rate(Acro) mode, Stabilize mode, and all other modes. It is also the most criti cal gain to adjust for your copter.
The outer PI loop generates the desired rate of angular rotation. The input for this loop can either be user with stick movement, or the stabilizer, which tries to achieve a specific angle.
To get a better idea of the fl ow of command to motor output, here is a diagram of the Roll control. 

### PID Rate Tuning Parameter: RATE_RLL_P and RATE_PIT_P are the proportional response and the default is 0.14. Your copter will vary quite a bit depending on the weight and thrust of
your e ngines. If your copter oscillates rapidly, lower this value. If it is sluggish, raise the value. This is the #1 parameter that needs tuning. If it is not right, every other parameter is a waste of time.
Parameter: RATE_RLL_I and RATE_PIT_I are set to 0 by default. Use this value to maintain tight control of the speed of rotation the copter. If the copter is not achieving the rotation rate needed to hold a tight attitude, this term will make up the difference.
Parameter: RATE_RLL_D and RATE_PIT_D is .0025 by default. This value will dampen the acceleration towards the target angle. It If the value is too high you will see small, fast oscillations in pitch or roll. You may even temporarily lose control of pitch or roll as the D term saturates the control outpu t.Page | 86

Parameter: STAB_D is .06 by default. This dampens the acceleration of rotation of the copter and can eliminate those small wobbles after a set point change (a quick angle change). This is similar to RATE_RLL_D but only dampens acceleration. STAB_D is si milar to RATE_RLL_D, but it’s unfiltered (faster) and has inherently less noise than RATE_RLL_D. Just as the RATE_RLL_D, a large value may cause oscillations or temporarily loss of control of pitch or roll as the D term saturates the control output.

Note: When tuning your copter, set RATE_I and RATE_D to zero, and only tune RATE_P. Once you have that dialed in, then tune RATE_I and RATE_D. 

### PI Control Tuning Parameter: STB_RLL_P and STB_RLL_P is by default 4.5 or 4.5° per second rotation for every 1° of erro r. If you want more or less speed of rotation based on user input, adjust this value. A larger Octo may want to have a smaller number, 3.5 perhaps, or you will get a large seesaw style oscillation.
Parameter: STB_RLL_I and STB_PIT_I are used to overcome im balance in the copter. If the copter is not symmetrical this I term will bring the copter to level. The higher the number the faster the copter will compensate. Low numbers can have adverse effects by causing a very slow oscillation measured in seconds. If you use this term, consider potential conflicts in timing with Rate_I. It may be best to keep one or the other zero.Page | 87



## Altitude Hold Tuning Altitude Hold uses a throttle value as the center point for all throttle adjustments. A simple averaging filter loo ks at the climb_rate and determines this value during stabilization. This value will change during the course of the flight because of voltage drop off.



### PI Control The altitude error is calculated in centimeters and fed to the controller. The first stage o f the controller takes the altitude error and decides how fast the copter should go to reach the correct altitude.
Parameter: THR_ALT_P is by default .4 or 40 cm/s for a 1m error. The desired rate maxes out at 1m/s.
Parameter: THR_ALT_I is used to close th e gap between the actual hover throttle and current assumed hover throttle. For example, if your copter hovers at 52% throttle, and your set point is 4% your copter will fall until it reaches equilibrium with THR_ALT_P times the error. This is called a ste ady state error, and leaves your copter too high or too low. THR_ALT_I will increase to effectively raise the throttle to 52%. The higher the number the faster it happens. If your number is too high it will cause oscillations.



### PID Rate Control Now that we have a desired rate, we need to change the thrust to give us that rate.
Parameter: THR_RATE_P is the proportional response and the default is .35. Your copter will vary quite a bit depending on the weight and thrust of your motors. If your copter oscillate s up and down in alt hold, lower this value.
Parameter: THR_RATE_I is set to 0 by default. It should, in theory, fix issues with a bad THR_RATE_P value, but it’s best to just get that tuned well in the first place.
Parameter: THR_RATE_D is 0.02 by default, but the noise of the Baro sensor can cause issues. If the value is too high you will see bad oscillations or pulsing of the motors. Once the THR_RATE_P value is dialed in, start at 0, and increment slowly. You should see oscillations die down.Page | 88



## Loiter an d Navigation Tuning Loiter and navigation use the same PID rate controllers.
The location error is calculated in centimeters for X (Longitude) and Y(Latitude) which is fed to the controller. The first stage of the controller takes the XY position error and decides how fast the copter should go to reach the correct location.



### PI Control Parameter: HLD_LAT_P and HLD_LON_P is by default .4 or 40 cm/s for a 1m error. The desired rate maxes out at 150cm/s. This doesn’t limit the pitch of the copter, The rate cont roller will do what it takes to maintain this speed as it approaches the location.
Parameter: HLD_LAT_I and HLD_LON_I are used to overcome wind that may be pushing us away from our target. The higher the number the faster the copter will compensate. If you r number is too high it will cause oscillations and overshoot.



### PID Rate Control Now that we have a desired rate, we need to change the copter pitch and roll to give us that rate of travel.
Parameter: LOITER_LAT_P and LOITER_LON_P are the proportional respo nse and the default is 2.2. Your copter will vary quite a bit depending on the weight and thrust of your engines. If your copter overshoots the target, lower this value.
Parameter: LOITER_LAT_I is set to 0 by default. Use this value to maintain tight contr ol of the speed of the copter. If the copter is not achieving the speed it needs, this term will make up the difference by tilting the copter more or less.
Parameter: LOITER_LAT_D is 0.015 by default, but the effect is not well tested. If the value is too high you will see small oscillations in pitch or roll. Once the LOITER_LAT_P value is dialed in, start at 0, and increment slowly. You should see oscillations die down.Page | 89



## Sensor Testing
Connecting to Mission Planner

 Start Mission Planner and hook up your A PM or PX4 board via the USB port.

 Ensure that the correct COM port for your APM or PX4 is selected and click on the “Connect” button on the right.

 With MAVlink connected, move the APM board and you should see the “Artificial Horizon” in the HUD move accord ingly.

 In an artificial horizon, when the aircraft tilts to the right, the horizon tilts to the left. (Just tilt your head and you can visualize this). This is normal! Please don’t tell us it’s reversed ;

- )

 In the below example, the quad is tilted a bit to the right.

 Unless you have the GPS module connected, are outside and have GPS lock, the map will not show your current position.
You can see the output from all the various sensors by clicking on the “Tuning” checkbox on the bottom right of the display 1 t his will bring up the graphical sensor display. If you click on the legend at the top of it 2 , it will bring up a window “Graph This” that allows you to choose which sensors and data outputs to display.Page | 90



## Mission Planning and Analysis

Here are some of the features of Michael Oborne’s Mission Planner:

 Point

- and

- click waypoint entry, using Google Maps.

 Full ground station for monitoring missions and sending in

- flight commands.

 Select mission commands from drop

- down menus

 See sensor output and test autopilot performance

 Download mission log files and analyze them

 Configure APM settings for your airframe

 See the output from APM’s serial terminal 

### Planning a Mission with Waypoints and Events In Mission Planner you can create missions use the e asy point

- and

- click Waypoint Editor created by Michael Oborne.
Note: Although this uses APM: Copter as the main example the primary methods apply for APM: Plane and APM: Rover although altitude control is severely limited in APM: Rover

. It is very importan t to acquire GPS lock before arming in order for RTL, Loiter, Auto or any GPS dependent mode to work properly.Page | 91



### Basic Waypoint Commands A mission file is a little intimidating to the human eye, but is a powerful scripting language for the autopilot. (Agai n, remember that the GCS will soon take care of all of this for you. You shouldn’t have to see it yourself for long!).
You can have as many commands as you want, ranging from pre

- programmed ones to ones that you can create. Here are some common ones:

 {NAV_ WAYPOINT n/a, alt, lat, lon}

 {NAV_TAKEOFF pitch, target altitude}

 {NAV_LAND n/a, alt, lat, lon}

 {DO_JUMP waypoint, n/a, repeat count, n/a} Goes to that waypoint and resumes mission there. Set repeat count to any number greater than 1 to do it that many tim es. or to

- 1 to do it forever. Good for looping missions.
( Note: DO_xxx commands currently need a dummy waypoint placed after the command
eg:

 WAYPOINT_1

 DO_SET_HOME

 WAYPOINT_2
Home will be set at WAYPOINT_1 but will not work if WAYPOINT_2 is not there.)
Tips

 Prefetch: You can cache map data so you don’t need Internet access at the field. Click the

Prefetch button, and hold down Alt to draw a box to download the selected imagery of a location.

 Grid: This allows you to draw a polygon (right click) and autom atically create waypoints over the selected area. Note that it does not do “island detection”, which means if you have a big polygon and a little one inside of that, the little one will not be excluded from the big one (see this for more). Also, in the case of any polygon that partially doubles backs on itself (like the letter U), the open area in the center will be included as part of the flyover.

 Setting your home location to the curre nt location is easy, just click “Home Location” above where you enter your home location, and it will set your home location to the current coordinates.

 You can measure the distance between waypoints by right

- clicking at one end and selecting Measure Dista nce. Then right

- click on the other end and select Measure Distance again. A dialog box will open with the distance between the two points.Page | 92



### Setting a Home Position
For APM: Copter the home position is set as the location where the copter was armed. This mea ns if you execute an RTL in APM: Copter , it will return to the location where it was armed, so arm your copter in the location you want it to return to.

For APM: Plane the home position is the location of the plane where the GPS was locked. This means if
y ou execute an RTL in APM: Plane , it will return to the location where it first acquired the GPS lock, so only power up your plane in the location you intend it to return to when performing an RTL.



### Instructions Note: When APM: Copter executes the Land command it will land from its current location. It will not fly to a location, then land like the planes do. If you want to land at a particular waypoint, you must fly to a normal WP, then the next command will be Land. The Absolute Alti tude checkbox in the Mission Planner is ignored. Ardu Copter only uses the default relative altitude.

In the screenshot above, a mission for Ardu copter starts with an auto takeoff to 20 meters attitude; then goes to WP 2 rising to 100 meters altitude on t he way, then waits 10 seconds; then the craft will proceed to WP 3 (descending to 50 meters altitude on the way), then returns to launch. Since the default altitude is 100 meters, the return to launch will be at 100 meters. After reaching the launch posi tion, the craft will land. The mission assumes that the launch position is set at the home position.Page | 93

You can enter waypoints and other commands (see below for the full list). In the dropdown menus on each row, select the command you want. The column headin g will change to show you what data that command requires. Lat and Lon can be entered by clicking on the map. Altitude is relative to your launch altitude, so if you set 100m, for example, it will fly 100m above you.

Default Alt is the default altitude whe n entering new waypoints. It’s also the altitude RTL (return to launch) mode will fly at if you have “Hold Default ALT” checked; if you don’t have that checked, your aircraft will try to maintain the altitude it was at when you switched on RTL.
Verify heig ht means that the Mission Planner will use Google Earth topology data to adjust your desired altitude at each waypoint to reflect the height of the ground beneath. So if your waypoint is on a hill, if this option is selected the Mission Planner will increa se your ALT setting by the height of the hill. This is a good way to make sure you don’t crash into mountains!
Once you are done with your mission, select “Write” and it will be sent to APM and saved in EEPROM. You can confirm that it’s as you wanted by se lecting “Read”
You can save multiple mission files to your local hard drive by selecting “Save WP File” or read in files with “Load WP File” in the right

- click menu:Page | 94

Auto Grid You can also have the Mission Planner create a mission for you, which is useful for function like mapping missions, where the aircraft should just go back and forth in a “lawnmower” pattern over an area to collect photographs.
To do this, in the right

- click menu select Polygon and draw a box around the area you want to map. Then sele ct Auto WP, Grid. Follow the dialog box process to select altitude and spacing. The Mission Planner will then generate a mission that looks something like this:

Basic Waypoint Commands Waypoint

Option Alt Lat. Lon. Delay (sec onds ) Altitude (meters) Latitude Longitude

 Mavlink command is NAV_WAYPOINT

 Delay option is triggered after the craft reaches the waypoint radius. The Next command is loaded after the delay.

 Delay time is in seconds, the default is 0Page | 95

Waypoint Option Bitmask

– no yet available in the Mission Planner

bit 0 Altitude is stored 0: Absolute 1: Relative bit 1 Change Alt Between WP 0: Gradually 1: ASAP bit 2 bit 3 Req. to hit WP. Alt to continue 0: No 1: Yes bit 4 Relative to Home 0: no 1: Yes bit 5 bit 6 bit 7 Move to next Command 0: Yes 1: No

LOITER_UNLIM

Option Alt. Lat Lon. N/A N/A N/A N/A

 Will cause the craft to begin to Loiter at the current location when the command is invoked.

LOITER_TIME

Option Alt. Lat. Lon. Time (Seconds) Altitude (Meters) Latitude Longitude

 Will cause the craft to begin to Loiter at the current location when the command is invoked.

 Optionally give a location to loiter at that wp

– The clock starts ticking after the WP is reached.

LPITER_TURNS

Option Alt. Lat. Lon. Number of turns (N x 360°) Altitude (Meters) N/A N/A

 Will cause the craft to begin to orbit the current location when the command is invoked.

RETURN_TO_LAUNCH

Option Alt. Lat. Lon. N/A Altitude (Meters) N/A N/A

 Will cause the craft to return to the home position set when the craft is armed (requires GPS Lock!)

 If Altitude is 0, craft will return to home at the altitude specified by the Mission Planner

LAND

Option Alt. Lat. Lon. N/A N/A N/A N/A

 Will cause the craft to land at the current location when the command is invoked.

 If you have Sonar, the craft will stop holding position at 3 meters and drop straight down.

 The motors will not stop on their own, you must exit the AP mode to cut the enginesPage | 96

TAKEOFF

Option Alt. Lat. Lon. N/A Altitude (Meters) N/A N/A

 Will caus e the craft to take off and hold position until the altitude is reached.

CONDITION_DELAY

Option Dis. Lat. Lon. N/A Distance (Meters) N/A N/A

 Will override the next waypoint altitude.

 Useful when used after a delay or distance conditional command

CONDITION_CHANGE_ALT

Option Alt. Lat. Lon. N/A Altitude (Meters) N/A N/A

 Will override the next waypoint altitude.

 Useful when used after a delay or distance conditional command

CONDITION_YAW

Option Alt. Lat. Lon. Direction (1=Clockwise, 0=Counter Clockwise) Relative: amount (degrees), Absolute: ending angle (degrees) Speed (Meters) Relative angle change = 1, Absolute = 0

 Fine grain controls of the Yaw

DO_SET_MODE

Option Alt. Lat. Lon. N/A N/A N/A N/A

 Not Implemented

DO_JUMP

Option Alt. Lat. Lon. The desired command index N/A # of Jumps N/A

DO_CHANGE_SPEED

Option Alt. Lat. Lon. Speed (Meters/sec.) N/A N/A N/A * Speed change will stick until rebootPage | 97

DO_SET_RELAY

Option Alt. Lat. Lon. 1 = on, 0 = off,

- 1 = toggle N/A N/A N/A * Toggling the Relay will turn an off relay on and vice versa

DO_ REPEAT _RELAY

Option Alt. Lat. Lon. N/A # of repetitions Cycle time (seconds) N/A * Toggling the Relay will turn an off relay on and vice versa

DO_SET_SERVO

Option Alt. Lat. Lon. Servo channel (5

- 8) PWM (1000

- 2000) # of repetitions Cycle time (seconds)

DO_CONTROL_VIDEO

Option Alt. Lat. Lon. N/A N/A N/A N/A

DO_SET_ROI

Option Alt. Lat. Lon. Yaw tracking option Altitude (Meters) Latitude Longitude

 Setting will persist until reboot

 The location is optional

 The option is a number from 0 to 4

 MAV_ROI_NONE = 0: Yaw will hold its current angle

 MAV_ROI_WPNEXT = 1: Yaw will point at next WP

 MAV_ROI_WPINDEX = 2: Yaw will point at the desired WP at the index #

 MAV_ROI_LOCATION = 3: Yaw will point at the indicated location (The location in the command)

 MAV_ROI_TARGET = 4: Not implemented

Note: When you’re using the Jump command, remember that waypoint logic can be a bit confusing. A waypoint command means “start heading to this WP”, not “wait until you get to this WP.” So, for example, if you put a “Jump to WP1′′ command in

- between WP4 and WP5, the aircraft will never get to WP5. That’s because once it starts heading in the direction of WP5, it then executes the next command, which is the jump, and that take s priority. So in that instance, if you want the aircraft to hit WP5, you’d create a fake WP6 and issue the Jump command after that.Page | 98



## Data

- flash Logs
Log Types (Data

- flash vs. tlog ) There are two ways to record your flight data with Ardu Copter . With some exceptions, the two methods record very similar data but in different ways:

 dataflash logs (the subject of this page) use the APM or PX4′s onboard dataflash memory, which you can download after the flight. On Ardu Plane and Ardu Rover dataflash logs are c reated soon after start

- up. On Ardu Copter they are created after you first arm the copter.

 telemetry logs (also known as “ tlog ”) are recorded by the mission planner (or other ground station) when you connect your APM to your computer via your 3DR or Xbee wireless telemetry link. 

### Setting what data you want to record The LOG_BITMASK parameter controls what message types are recorded in the dataflash. If you only wish to enable one particular message type in addition to the defaults you can use the Log Bitm ask drop down in the Mission Planner’s Advanced Parameters list.Page | 99

For better control of exactly which messages are recorded you can use the CLI (command line interface) as follows:

 Go to the Mission Planner’s Terminal screen

 Press “Connect APM” or “Connect PX”

 type logs

 enable or disable one of the possible messages types by typing enable or disable followed by the message type. I.e enable IMU

The full list of possible dataflash messages for Ardu copter is:
ATT : roll, pitch and yaw (recorded at 50hz if enabled with ATTITUDE_FAST , 10hz if enabled with ATTITUDE_MED )

CAMERA : GPS time, vehicle roll, pitch, yaw, lat, lon and altitude at the moment the camera shutter is triggered
CMD : commands received from the ground station or executed as part of a mission
COMPASS : raw compass values and compassmot compensation values
CURRENT : battery voltage, current and board voltage information recorded at 10hz
CTUN : throttle and altitude information including pilot throttle input, sonar alt, and baro alt. recorded at 10hz
D32: id = 9, Simple Mode’s initial heading in centi

- degrees (i.e. 18000 = south)Page | 100

DU32: id = 7, bit mask of internal state. The meaning of individual bits can be found in Ardu Copter.pde’s definition of the ap structure

. ERR: error subsystem and error number. A list of these can be found on the “Diagnosing problems using LogFiles” wiki page

. EV: an event number. The full list of p ossible events can be found in defines.h but the most common

are:

10 = Armed

11 = Disarmed
15 = Auto Armed (pilot has raised throttle above zero and autopilot is free to take control of throttle)

16 = Takeoff
18 = Land Complete
25 = Set Home (home location coordinates have been capture)
GPS : gps position, altitude, number of satellites, hdop recorded at the update rate of the GPS (usually 5hz)

IMU : raw accelerometer and gyro information recorded at 50hz
INAV : inertial navigation altitude and position

MOTORS : individual motor levels recorded at 50hz
NTUN : navigation data including desired and actual velocity, desired acceleration, desired roll and pitch angles. recorded at 10hz while the autopilot is controlling the horizontal position (Loiter, RTL, Auto modes)
OPTFLOW : optical flow sensor velocities and desired roll and pitch angles if OF_LOITER is engaged
PID : resulting P, I and D outputs of the PID controller if it is being tuned with the CH6 tuning knob. recorded at 50hz
PM : performance information including number of loops running slow, longest loop time in ms (recorded once every 10seconds)

 Please note that there is a significant performance impact if you enable too many logs so in general you should stick with the defaults and only enable expensive logging like INAV, MOTORS and IMU when you need them to do some specific analysis.

 If you want to see which items you can log for other platforms, do the next steps:

 Note which items are enabled before you do the next steps

– write down the list.Page | 101  Type Enable All at the cli prompt. That will enable logging of all parameters for your platform

– some of which you may not want. You will see th e new list of all items now being logged.

 To remove the items in the list you do not want

– I.E. to return to the values initially set for logging type “disable” followed by the item name. Or you can go back to the Software

– Advanced Parameters and use th e Log bitmask(LOG_BITMASK) parameter and select one of the configurations for your vehicle. 

### Downloading Logs with the Mission Planner

 Go to the Mission Planner’s Terminal Screen

 Click “Connect APM” or “Connect PX4′′

 When the prompt appears click “Log Downlo ad”

 When the “Log” window appears click the checkbox of the log you wish to download (normally the highest number)

 Select your vehicle type ( APM: Copter , APM_Plane, and APM: Rover ). This ensures you get the correct scaling for a few parameters as the data is downloaded.

 Push “Download These Log”
For very large logs it can take several minutes to download but you should see the amount of data transferred so far in light grey just below the “Clear Logs” button. When the file is completely downloaded “Done” s hould appear in the area below the Clear Logs button..Page | 102

The Log will appear in your Mission Planner’s directory (the directory where the mission planner was installed) in a folder called “logs” or in the location you select in the Planner options [Config/Tu ning] [Planner]. The file will be of the format: YYYY

- MM

- DD HH

- MM ##.log where the date portion is the current date and the ## is the log number.
Along with the log file will be a .kmz file which show you a 3D view of the flight path if opened in Google Ea rth. A .gpx file is also produced but is rarely used.
Clearing logs:

 The Clear Logs button on the same screen will clear all logs when pushed.

 It is a good idea to save those log files you want to keep and clear all logs before a day of flying.

 Once the data

- flash memory card is full it will wrap around and start overwriting the oldest logs. 

### Viewing the contents Dataflash files can be opened for analysis by doing the following:

 Open the Mission Planner’s Terminal Screen

 push Log Browse button and open the .log dataflash file

The Log Browser screen will appear with a graphing area at the top. This graphing area’s size can be changed by clicking and holding on the area just below the graph but abo ve the green graphing buttons.

The basic format of the dataflash is:

 Line numbers appear on the very left side of the viewer

 Software version and board type appear at the top

 FMT messages are next which tell the mission planner the column headers for each message type

 PARM rows which show each parameter (in the order in which they appear in the eeprom) along with their value at the beginning of the flight

 Flight data messages including GPS, IMU, etc.Page | 103

Graph any flight data by first clicking on the appropria te row, you should see the column headers update appropriately. Next find the column you wish to graph, click on it and then push the “Graph this data” button. In the example above the ATT’s Roll

- In and Roll data have been graphed.

The mouse’s scroll wheel can be used to zoom in or out. You may also select an area of the graph to zoom in on it. Zoom out by right

- mouse

- button clicking and selecting “Set Scale to Default”.
You may also filter on just the first column (the flight data message type) by clicking on the first column and selecting the message type from the drop

- down. This is very useful especially for viewing the different flight modes (called “MODE” messages) used during the mission. Click the first column again but press “Cancel” to clear the filter.Page | 104



### Message Details ( APM: Copter specific) ATT (attitude information):
RollIn: the pilot’s desired roll angle in centi

- degrees

Roll: the vehicle’s actual roll in centi

- degrees
PitchIn: the pilot’s desired pitch angle in centi

- degrees

Pitch: the ve hicle’s actual pitch angle in centi

- degrees
YawIn: the pilot’s desired yaw rate as a number from

- 4500 ~ 4500 (not necessarily in deg/sec or any other understandable unit)
Yaw: the vehicles actual heading in centi

- degrees with 0 = north

NavYaw: the desired heading in centi

- degrees
CAM (time and position when camera shutter was activated):
GPSTime : the GPS reported time since epoch in milliseconds

Lat : the accelerometer + GPS latitude estimate
Lat : the accelerometer + GPS longitude estimate

Alt: the accel erometer + barometer estimated altitude in cm above ground
Roll: the vehicle roll angle in centi

- degrees
Pitch: the vehicle pitch angle in centi

- degrees
Yaw: the vehicle’s heading in centi

- degrees
CMD (commands received from the ground station or executed as part of a mission):

CTot: the total number of commands in the mission
CNum: this command’s number in the mission (0 is always home, 1 is the first command, etc)

CId: the mavlink message id
Copt: the option parameter (used for many different purposes)
Prm1: the command’s parameter (used for many different purposes)

Alt: the command’s altitude in meters
Lat: the command’s latitude positionPage | 105

Lng: the command’s longitude position
COMPASS (raw compass, offset and compassmot compensation values):
MagX, MagY. MagZ: raw magnetic field values for x, y and z axis
OfsX, OfsY, OfsZ: raw magnetic offsets (will only change if COMPASS_LEARN parameter is 1)
MOfsX, MOfsY, MOfsZ: compassmot compensation for throttle or current
CURRENT (battery voltage, current and board voltage information):
Thr: pilot input throttle from 0 ~ 1000
ThrInt: integrated throttle (i.e. sum of total throttle output for this flight)
Volt: battery voltage in volts * 100

Curr: current drawn from the batt ery in amps * 100
Vcc: board voltage
CurrTot: total current drawn from battery
CTUN (throttle and altitude information):
ThrIn: the pilot’s throttle in as a number from 0 to 1000
SonAlt: the altitude above ground according to the sonar

BarAlt: the altitude above ground according to the barometer
WPAlt: the desired altitude while in AltHold, Loiter, RTL or Auto flight modes

NavThr: not used
AngBst: throttle increase (from 0 ~ 1000) as a result of the copter leaning over (automatically added to all pilot and autopilot throttle to reduce altitude loss while leaning)
CRate: accelerometer + baro climb rate estimate in cm/s
ThrOut: final throttle output sent to the motors (from 0 ~ 1000). Normally equal to ThrIn while in stabilize mode.

DCRate

– pilot desired climb rate in cm/s
D32, DU32 (single data values which are either signed 32bit integers or unsigned 32bit integers):

id: identification number for the variable. There are only two possible valuesPage | 106

7 = bit mask of internal state. The meani ng of individual bits can be found in ArduCopter.pde’s definition of the ap structure

. 9 = simple mode’s initial heading in centi

- degrees
ERR ( an error message):
SubSystem and Error codes listed below

1. 1: Main (never used) 2. 2: Radio
ECode 1: “Late Frame” which means the APM’s onboard ppm encoder did not provide an update for at least 2 seconds
ECode 0: error resolved which means the ppm encoder sta rted providing data again

3. Compass
ECode 1: the compass failed to initialize (likely a hardware issue)
ECode 2: failure while trying to read a single value from the compass (probably a hardware issue)

ECode 0: above errors resolved

4. Optical flow

Ecode 1: fa iled to initialize (likely a hardware issue)

5. Throttle failsafe
ECode 1: throttle dropped below FS_THR_VALUE meaning likely loss of contact between RX/TX
ECode 0: above error resolve meaning RX/TX contact likely restored

6. 6: Battery failsafe
ECode 1: battery voltage dropped below LOW_VOLT or total battery capacity used exceeded BATT_CAPACITY

7. G PS failsafe

ECode 1: GPS lock lost for at least 5 seconds

ECode 0: GPS lock restoredPage | 107

8. GCS (Ground station) failsafe

ECode 1: updates from ground station joystick lost for at least 5 seconds
ECode 0: updates from ground station restored

9. Fence

ECode 1: altitude fence breached

ECode 2: circular fence breached

ECode 3: both altitude and circular fences breached

ECode 0: vehicle is back within the fences

10. Flight Mode
ECode 0 ~ 10: the vehicle was unable to enter the desired flight mode
(0=Stabilize, 1=Acro, 2=AltHold, 3=Auto, 4=Guided, 5=Loiter, 6=RTL, 7=Circle, 8=Position, 9=Land, 10=OF_Loiter)

GPS:

Status

– 0 = no GPS, 1 = GPS bu t no fix, 2 = GPS with 2D fix, 3 = GPS with 3D fix
Time: the GPS reported time since epoch in milliseconds
NSats: the number of satellites current being used

HDop : a measure of gps precision (1.5 is good, >2.0 is not so good)

Lat: Latitude according to the GPS
Lng: Longitude according to the GPS

RelAlt: Accelerometer + Baro altitude in meters
Alt: GPS reported altitude (not used by the flight controller)
SPD: horizontal ground speed in m/s
GCrs: ground course in degrees (0 = north)
IMU (accelerometer and gyro information):
GyrX, GyrY, GyrZ: the raw gyro rotation rates in degrees/second
AccX, AccY, AccZ: the raw accelerometer values in m/s/sPage | 108

INAV (inertial navigation position and veloc ity estimates):

BAlt: barometer altitude in cm

IAlt: inertial nav altitude estimate in cm
IClb: inertial nav estimated climb rate in cm/s

ACorrX. ACorrY, ACorrZ: x, y and z

- axis accelerometer correction in cm/s/s
GLat, GLon: GPS latitude and longitude from home
ILat, ILng: inertial nav latitude and longitude from home
Mode (flight mode):
Mode: the flight mode displayed as a string (i.e. STABILIZE, LOITER, etc)
ThrCrs: throttle cruise (from 0 ~ 1000) which is the autopilot’s best guess as to what throttle is required to maintain a stable hover
Motors (pwm output to individual motors):
Mot1, Mot2, etc : pwm command sent from flight controller to the esc/motor
NTUN (navigation information):
WPDst: distance to the next waypoint (or loiter target) in cm. Only upd ated while in Loiter, RTL, Auto flight modes.
WPBrg:bearing to the next waypoint in degrees
PErX: distance to intermediate target between copter and the next waypoint in the latitude direction
PErY:distance to intermediate target between copter and the nex t waypoint in the longitude direction
DVelX: desired velocity in cm/s in the latitude direction
DVelY: desired velocity in cm/s in the longitude direction
VelX: actual accelerometer + gps velocity estimate in the latitude direction

VelY: actual acceleromet er + gps velocity estimate in the longitude direction
DAcX: desired acceleration in cm/s/s in the latitude direction
DAcY: desired acceleration in cm/s/s in the longitude directionPage | 109

DRol: desired roll angle in centi

- degrees
DPit: desired pitch angle in centi

- degrees
PM (performance monitoring):

RenCnt: DCM renormalization count

– a high number may indicate problems in DCM (extremely rare)

RenBlw:DCM renormalization blow

- up count

– how many times DCM had to completely rebuild the DCM matrix since the last PM. Normally innocuous but a number that constantly grows may be an indication that DCM is having troubles calculating the attitude (extremely rare)
FixCnt: the number of GPS fixes received since the last PM message was received (it’s hard to imagine how this would be useful)
NLon: number of long running main loops (i.e. loops that take more than 5% longer than the 10ms they should)
NLoop: the total number of loops since the last PM message was displayed. Normally 1000 and allows you to calculate the perce ntage of slow running loops which should never be higher than 15%.
MaxT: the maximum time that any loop took since the last PM message. This should be close to 10,000 but will be up to 6,000,000 during the interval where the motors are armed

PMT: a number that increments each time a heart beat is received from the ground station
I2CErr: the number of I2C errors since the last PM message. Any I2C errors may indicate a problem on the I2C bus which may in turn slow down the main loop and cause performance prob lems. 

### Viewing KMZ FILES When you download the dataflash log files from the APM/PX4 it will automatically create a KMZ file (file with extension .kmz). This file can be opened with Google Earth (just double click the file) to view your flight in Google Eart h. Please see the instructions on the Telemetry Logs Page for additional details.Page | 110



## Mission Planner Telemetry Logs Tlogs are recordings of the MAVLink telemetry messages sent between the APM/PX and the ground station and are automatically created the moment you press the connect button on the mission planner. Files of the format YYYY

- MM

- DD hh

- mm

- ss.tlog appear in the “logs ” subfolder in your Mission Planner installation folder or to the location you select in the Planner options [Config/Tuning] [Planner].
Besides the “.tlog” files, “.rlog” files are also created. These contain all the .tlog data plus additional debug outpu t from the mission planner. but cannot be parsed or played back so they should be ignored. 

### Setting the data rate The desired rate at which data is sent from the APM/PX to the ground station can be controlled through the mission planner’s Software > Planne r screen’s Telemetry drop

- downs. Because all data sent over the telemetry link is also recorded in the tlog, this also controls the rate of data saved to the tlogs.
Note that especially on Ardu Copter , due to CPU resource limitations, the actual rate of t he data sent and saved may be lower than the rate requested.



### Playing back missions If you are using wireless telemetry and have connected to APM via the Mission Planner, your flight data will automatically recorded. You can play back these logs by doing the following:

 Open the mission planner’s Flight Data screen

 click on the Telemetry Logs tab

 Press “Load Log” and find the flight’s tlog file

 Press “Play”Page | 111

You can also jump to the point of interest in the log using the slider and control the speed of the playback with the predefined Speed buttons.
While the log is replaying, the HUD will move and the vehicles location on the map will update as it did during the flight. Individual data values can be seen through the Status tab and you can even display them in a graph by clicking on the “Tuning” checkbox under the map and then double clicking on the data legend to bring up a box from which you can choose exactly which data fields are graphed as shown below. This will show the recorded data changing as the f light progresses.Page | 112



### Creating 3d images of the flight path You can create KMZ files by doing this:

 Open the mission planner’s Flight Data screen

 Click on the Telemetry Logs tab

 Press the “Tlog > Kml or Graph” button

 Press the “Create KML + GPX” button

 selec t the flight tlog

A .kmz and .kml file will be created alongside the original .tlog and this can be opened in Google earth to interactively view the 3d flight path. You can open the kmz file in Google Earth to view the flight or path. Just double click th e file or drag it and drop into Google Earth.

The different flight modes used during the flight will appear as different colored tracks. You can change some details about how the flight paths are displayed including their color and whether the paths
exte nd to the ground by doing this:

 Find the log file’s name in the “Places” pane on the left. It should appear in a “Temporary Places” folder.

 Right click on an individual path and select “Properties” to open the Edit Path window.

 The color can be changed on the “Style, Color” tab

 The area below the path can be removed (added) on the “Altitude” tab by un

checking (checking) “Extend path to ground” 

### Extracting parameters and Waypoints You can extract the parameters and waypoints from the tlog by following the same steps as for creating the KML file except that at the last step select “Extract Params” or “Extract WPs”.Page | 113

Extract Params will cause a .param file to be created alongside the t log. This file is tab separated and contains a full list of parameters (in the same order as they appear in the eeprom) along with their values during the flight. This can be opened in excel or a text editor.

Extract WPs will create one or more .txt file s containing any missions uploaded to the APM/PX4. These files can be opened in the Mission Planner by switching to the Flight Plan screen, right

- mouse

- button clicking on the map and selecting “File Load/Save”, “Load WP File”.



### Graphing data from a flight Data from the flight can be graphed by doing the following:

 Open the mission planner’s Flight Data screen

 Click on the Telemetry Logs tab

 Press the “Tlog > Kml or Graph” button

 Press the “Graph Log” button

 select the flight tlog

 When the “Graph This” scre en appears, use the left or right mouse button to click on the checkboxes beside the items you wish to graph. Note that the items are grouped into categories like “RC_CHANNELS” and “RAW_IMU” although it’s still often difficult to find exactly the item you wish to graph

 If you use the left mouse button the scale for the item will appear on the left of the graph. If you use the right mouse button it will appear on the right

 Click the checkbox multiple times to cycle through all the possible colors

 Change t he zoom of the graph with your mouse’s middle wheel, by select an area of the graph with the left mouse button held down or by right

- mouse

- button clicking on the graph and selecting “Set Scale To Default”Page | 114



## Using a Ground Station
1. Air speed ( Ground speed if no airspeed sensor is fitted ) 2. Crosstrack error and turn rate (T) 3. Heading direction 4. Bank angle 5. Wireless telemetry connection (% bad packets) 6. GPS time 7. Altitude ( blue bar is rate of climb ) 8. Air speed 9. Ground speed 10. Battery status 11. Artificial Horizon

The above is the main Ground Station view of the Mission Planner, showing the Heads

- up Display (HUD). If your APM slider switch is in flight mode (away from the RC pins) and you have connected via MAVLink (usually through the Xbee modules at 57600k, but it will work via USB on the ground, too) the dials and position on this screen will display the telemetry sent by APM.
A few tips:

 The map will only show current position when you have GPS lock or are using a flight simulatorPage | 115

 Remember how artificial horizons work: when the aircraft tilts to the right, the horizon tilts to the left. (Just tilt your head and you’ll see what I mean). This is normal! Please don’t tell us it’s reversed ;

- )

 For APM: Copter status, the output meaning is as follows:

 “WPDist” : Distan ce to next waypoint in meters

 “Bearing ERR”: How far your UAV is from the perfect line to the next waypoint

 “Alt ERR”: How far your UAV is from the target altitude

 “WP”: Next waypoint to hit

 “Mode”: Current autopilot mode.

 You can issues mode changes and o ther action commands in the air with the Mission Planner and other GCSs, but note that you must be under autopilot control for them to take effect.

 If you double

- click the HUD it will pop out , allowing you to run the HUD full screen on a second

screen.

 If you double

- click on the Speed Gauge you can modify the max scale you want to display.

 You can change the voice used in the speech synthesis in the Ease of Access center in Windows Control Panel. Go to the “Text to Speech” options.

 If you enable the Tuning checkbox and double

- click tuning you can graph any data that is available in the status tab. This means you can have alt, attitude, or many other options in real time.

 You can use custom imagery instead of Google Maps. Press control

- F. This allows you to u pload
your own ortho

- photos . Use will require Global mapper , as this is currently one of the key steps in exporting in the required format for use in the planner.



### Guided Mode One of the most commonly

- used features in pro UAVs is point

- and

- click mission co ntrol in real time. Rather than just pre

- planned missions or manually flying the UAV, operators can just click on a map and say “go here now”.
That’s now implemented in the Mission Planner. On the GCS map, you can right

- click on the map and just select “Fl y To Here”. The UAV will fly there and loiter until you give it another command. We call this “Guided Mode”. There are more commands coming in this mode soon, but the functionality is now built

- in.
Note: Guided is a separate flight mode. If you enter it yo u will remain in it until you do something to change modes. So if you tell it to “go here now”, once it arrives there it will loiter at the Guided waypoint till you tell it to do something else. Something else could either be going to another Guided waypoi nt (staying in Guided mode) or changing to some other flight mode. If you change to Auto your mission will resume where it left off.Page | 116



### APM 2.6

 APM 2.6 is a revision of the APM that makes use of an external magnetometer (compass).

 The APM 2.6 has no on board compass, and is optimized for vehicles where the compass should be placed as far from power and motor sources as possible to avoid magnetic interference.

 APM 2.6 is designed to be used with the 3DR GPS uBlox LEA

- 6 with Compass module.

 The GPS/Compass modu le may be mounted further from noise sources than the APM itself.

 APM 2.6 requires a GPS unit with an on board compass for full autonomy.

 For information on installing a 3DR GPS uBlox LEA

- 6 with Compass, visit (Here!)

.

 Details APM 2.0Page | 117



### Using the APM 2.5/2.6 Enclosure The APM 2.5/2.6 board is shipped in an enclosure with foam protecting the barometric pressure sensor, as shown here.



### Powering the APM 2.5/2.6 Board Like any computer, the APM needs a power supply with a steady clean voltage and sufficient current.
3DR provides an APM power module that supplies 2.25A at 5.37V. The module is designed to convert power from the main flight battery (18 volt maximum). That module will supply sufficient power for your APM, and low power radios including your RC receiver (without servos). Your RC receiver can be powered from any APM Input (+5V and ground). This is normally done by connecting a 2 or 3 wire cable between an APM Input and one of the output channels on the RC rad io.
If you are using any servos such as are required with a traditional helicopter or a camera gimbal, you will needPage | 118

to provide an additional dedicated power supply for the servos. The APM is intended to control servos, not power them.
In order to design a power supply for your APM, or provide additional power, you’ll need a basic understanding of the power circuit in the APM.
There are two “sides” to the positive circuit in the board. Each side has positive

- rails available for inputting power or distributi ng it to peripheral devices. The center row of pins in the three groups of pins (Outputs, Inputs, Analog) labeled “+” are referred to as a “positive

- rail”. This means that the base of all the + pins are connected so they represent a single electrical path. The positive

- rails of the Input and Analog group are connected together. So we have two separate positive circuits, one in the Outputs and the other made up of the Input/Analog.
All of the components on the board take power from various points on these ra ils, so it is necessary for both “sides” to be receiving +5V (within the specs below) for the board to function.
These positive

- rails can be joined together by placing JP1 in its position on the board. This connects all the positive

- rails and provides powe r to both sides of the board, so that low

- level power can be distributed to peripheral sensors and devices: 3DR Radios, sonar, RC Rx, etc. via the power

- rails.
When using the power module, the circuit path is as follows:
From the power module connection th e negative wire is connected to a negative

- rail shared by the entire board regardless of JP1.
Positive voltage comes in to a T

- junction. to the left is a path through the JP1 to the positive

- rail of the Outputs. To the right it flows through an over

- voltag e, over

- current, reverse

- polarity protection(500mA fuse and 6V Zener diode). A side effect of passing through the Zener diode is a .37V loss, therefore input voltage should be bumped up by .37V to account for this. From here the positive voltage runs to th e positive

- rails of the Inputs and Analog. Inputs should not be used to power anything except your RC receiver.
Higher current loads such as servos should be powered from the power

- rails (positive

- negative) of the Output side. You must use an adequate volt age

- regulator to provide power directly to the Output
power

- rails, all servo power leads will attach to these same rails (the signal wires can connect on the Analog “S” pins in the case of a camera gimbal). Since JP1 is removed in this scenario, the other “side” of the board will need power provided to its power

- rails directly.Page | 119



### Alternative ways to power your board

3DR Power Module If you are using the 3DR Power :

 Warning! Under no circumstances should you ever attempt to draw servo power from the analog input connector.

 Warning: You may “control” servos from A9, A10 and A11 from the A0

– A11 I/O connector, but you must run servo power separately.

 The A0

– A11 I/O connector cannot supply sufficient power for servos.

 A9, A10 and A11 of the I/O connector com e pre

- wired to correct digital out for use as servo control lines.

 For servo use, it is imperative that they have not been reassigned to analog use with the pads on the back of the APM board. 

### A Non technical Description of the Power Supply Requirements The description below simply supplements and provides an alternate view of the information above.

1. The APM 2.5/2.6 board has two separate power circuits which make it very easy to power by a variety of methods. A. A fused power circuit provides primary board and general I/O power: (It cannot provide power for servos). B. The Other power circuit is for the OUTPUT connector power rail: (it can provide power for servos). 2. The jumper JP 1 determines whether the two power circuits are connected or separate. A. If JP1 is remov ed, the power rail on the OUTPUT connector “Floats” and may be used to distribute power. B. Although if JP1 is removed the OUTPUT connector cannot be used to supply power to the APM board. 3. It is possible to power the APM board from the Power Module connector or the OUTPUT or INPUT connectors. 4. Normally the APM 2.5/2.6 “Power Module” is used to provide primary APM 2.5 board and general I/O power.
5. Alternatively primary board power can be supplied by a BEC either from one of the ESCs or from an external BEC. 6. If se rvos are used, supplementary power is required. A. Generally one power supply is provided for the board and one or more additional power supplies for the servos. B. But if a sufficiently large external BEC is used it can supply power for both via the OUTPUT conn ector. 7. Only the OUTPUT connector can provide power for servos as the other circuit is fused. A. The address connector is sometimes used provide servo signals, but the servos power must come from elsewhere.Page | 120

8. How you are powering your APM board and or servos det ermines whether JP1 is installed or
not. A. (Whether the two power circuits are separated or connected).
B. All possible configurations are detailed Below. 9. The type of use will determine which options are available. A. APM: Copter can power the APM from a power module or a UBEC or a BEC from one of the ESCs and can power servos from a UBEC or from the other ESC’s BECs.
B. APM: Plane can power the APM from the power module, the BEC from the flight motors ESC or a separate UBEC and ca n power servos from a separate UBEC or the flight motors BEC if it is large enough. C. APM: Rover can power the APM from the power module, the BEC from the drive motor’s ESC or a separate UBEC and can power the steering servo from a separate UBEC or the dr ive motors BEC if it is large enough. 

### Power Supply Rails Connected Requirements (JP1 Installed) Warning: Do not exceed Abs MAX input voltages when connecting the power supply or you will damage your board. Warning: Connecting USB when you have input voltag es at the high end of the range (near Abs Max) can damage the board. Disconnect battery before connecting USB or test input voltages so they are within the specified range.

Power Options Nominal Abs MAX JP1 Status Power on Output PWM connector 5.37V +/

- 0 .5 6V JP1 Connected Power on Input PWM connector 5.00V +/

- 0.25 5.5V JP1 Connected 

### No Power Module and No Servos and Power provided by BEC from ESC

 If you do not have a power module and you are not using servos.

 Ensure JP1 is installed and provide the necessary power via the BEC from one of your ESC’s.

 Connect one ESC’s BEC power and ground wires to one pair of the APM OUTPUT connector’s power and ground pins.

 Clip the BEC power leads on the remaining 3 wire connectors.

 Ensure that the ESC’s signal wires are connected to the appropriate APM OUTPUT connector signal pins.

 You must ensure that your ESC’s BEC has a sufficient power capability (at least 2 amps).

 Most 20 amp or higher ESCs have 2 amp BECs. 

### No Power Module but using Servos and a high power External BEC

 If you do not have a power module and are using servos you can use a high power external BEC.

 Ensure JP1 is installed and provide the necessary power via a high power external BEC (5 to 10 amps or more).

 The BEC power must be provided to one pair of the APM OUTPUT connector pins.

 Warning! Clip all power leads on the ESC’s BECs (they would conflict with the external BEC).

 Your servos will determine the size of the BEC required.Page | 121

 You should allow at least 2 or 3 amps extra to power the APM, recei ver and to prevent (brown outs).

 All of the positive power for driving each servo must come from the OUTPUT connector.

 This is true even if the servo(s) signal wires are connected to the ADDRESS connector.

 This option requires you to take responsibility fo r providing sufficient power to prevent brownout. 

### No Power Module but using Servos and multiple BECs from ESC’s (A BEC for each Servo)

 If you do not have a power module and are using servos you can use multiple BECs from your ESC’s.

 Ensure JP1 is installed and plug one of your ESC’s signal cables with power leads into the OUTPUT connector.

 Remove the power and ground leads from the remaining ESCs signal cable connectors.

 Plug the signal wire connector from each ESC onto the appropriate pin on the OUTPUT con nector.

 You can heat shrink these or plug them into a multi

- wire connector appropriate for your copter.

 Connect one pair of each of the remaining BEC power and ground lines to the power and ground of each individual servo.

 Clip or heat shrink any remaining excess BEC power and ground leads.

 The BEC power from one ESC must be provided to one pair of the APM output connector pins.

 Plug only the signal input wire from your servos into the appropriate OUTPUT or ADDRESS connector pin.

 Your ESC’s BECs should be a t least 2 amps.

 The ESC’s BEC grounds are in common with battery and internal signal ground so grounding the servos this way is OK. 

### Power Supply Rails Not Connected Requirements (JP1 Not Installed) Warning: Do not exceed Abs MAX input voltages when connect ing the power supply or you will damage your board. Warning: Connecting USB when you have input voltages at the high end of the range (near Abs Max) can damage the board. Disconnect battery before connecting USB or test input voltages so they are within th e specified range.

Power Options Nominal Abs MAX JP1 Status Power on Output PWM connector 5.00V +/

- 0.5 6V JP1 open Power on Input PWM connector 5.00V +/

- 0.25 5.5V JP1 open


### Power Module and No Servos

 If you have a power module and you are not using servos.

 Ensure JP1 is not installed.Page | 122

 Provide the necessary power via the power module connected to the APM’s power module
connector.

 When connecting your ESCs to the OUTPUT connector clip the BEC power leads on each ESC’s 3 wire connector.

 Or connect only the ESC’s signal wires to the OUTPUT connector. 

### Power Module and using Servos with External BEC power

 If you have a power module and an external BEC and you are using servos.

 Ensure JP1 is Not installed

 Provide APM board and receiver power via the power mo dule connected to the power module
connector.

 Connect an external BEC with sufficient power for your servos to one pair of the OUTPUT connector power pins.

 When connecting your ESCs to the OUTPUT connector clip the BEC power leads on each ESC’s 3 wire conn ector.

 Or connect only the ESC signal wires to the OUTPUT connector. 

### Power Module and using Servos with BEC power from one ESC

 If you have a power module and you are using servos Remove JP1.

 Provide APM and receiver power via the power module connected to the APM’s power module
connector.

 The BEC of a single ESC must provide sufficient power for all your servos.

 When connecting your ESCs to the OUTPUT connector clip the BEC power leads on all but one of the ESC’s connectors.

 Or connect only the ESC signal w ires to the OUTPUT connector for all except one ESC.

 And on that ESC connect all 3 wires to the OUTPUT connector. 

### Power Module and using Servos with BEC power from one ESC

 If you have a power module and you are using servos Remove JP1.

 Provide APM and rece iver power via the power module connected to the APM’s power module
connector.

 The BEC of a single ESC must provide sufficient power for all your servos.

 When connecting your ESCs to the OUTPUT connector clip the BEC power leads on all but one of the ESC’s connectors.

 Or connect only the ESC signal wires to the OUTPUT connector for all except one ESC.

 And on that ESC connect all 3 wires to the OUTPUT connector. 

### No Power Module and using Servos with BEC power from two ESCs

 If you do not have a power module and you are using servos remove JP1.

 Provide APM and receiver power via 1 pair of ESC

- BEC power wires connected to the APM INPUT connector power pins.

 Also connect another of the ESCs power wire pair to the OUTPUT connector.Page | 123

 The BEC of a single ESC must pr ovide sufficient power for all your servos.

 Clip the signal power leads on your remaining ESC’s.

 Connect all ESC signal wires to the appropriate OUTPUT connector pins.Page | 124



## APM 2.5/2.6 Connections
1. Outputs and Inputs 2. Common negative

- rail (pins closest to edge “

- ”) provides a negative path to complete power and signal circuits 3. Separate positive

- rails (central pins “+”) for low

- level power distribution 4. Individual sensor/signal pins (inner pins “S”) output control signals to
motor

- ESCs and take

- in RC input signal s from the Rx 5. Micro USB 6. Direct connection to a computer 7. Power Module 8. Provides power input and battery monitoring capability 9. 3DR Radio 10. Two

- way wireless telemetry and control 11. 5.GPS 12. Input from GPS receiver (Rx) 13. Analog I/O
14. Common negative

- rail (outer “

- ”) shar ed with Inputs and Outputs 15. Positive

- rail (center “+”) is connected with the positive rail on the Inputs 16. Individual signal pins (inner “S”) connect with servos and sensors 17. I2C connection. 18. Inter

- Integrated Circuit, a type of serial bus. This allows multiple peripheral devices to be connected with a single port 19. Jumper

- JP1 20. Connects the positive

- rail of the Outputs to the positive

- rails of the Inputs

- Analog (details) 21. Optional I/O portsPage | 125



## Connecting your R/C Inputs and Motors
Connecting the RC inputs
Connect your RC receiver “S” (signal) pins to the “S” pins on Inputs of APM, using the jumper cable that came with your APM: Copter kit. You must c onnect at least channels 1 ~ 5. Channels 6 ~ 8 are optional

. Your RC receiver will require power. Normally this is done by using one 2 or 3 wire connector between the APM Inputs and one channel output on the receiver

If you are using a PPM Receiver , put a jumper on the “S” inputs of channel 2 and 3, and connect the PPM input to channel 1.Page | 126



### Connecting the RC Outpu ts to the Motors Connect the four

- wire/six

- wire cable from your power distribution board (PDB) to the corresponding “S” pins on the APM Outputs. It is not necessary to connect +5v or ground pins

– those connections are made on the PDB.Page | 127Page | 128



## Recognizing the clockwise and counter

- clockwise propellersPage | 129



### Checking the motor direction the simple way If you have completed the Radio and ESC calibration , you can check that your motors are spinning in the correction direction:

 Holding down your copter with the props clear of your body for safety, arm the ESCs (For a PX4 system, press and release the Arming button) hold you r throttle stick all the way to the right for four seconds.

 Now gently raise the throttle just a bit, until the props start turning. Note the direction each one turns. They should match directions shown in the images above for the frame you’ve chosen.



### Chec king the motor direction with the CLI An alternative way to check that the motors have been hooked up correctly is to use the “Motors” command in the CLI.

 Connect the APM or PX4 to your computer using the mini USB cable

 Connect the LiPo battery

 Open the Mi ssion Planner’s Terminal window and press “Connect to APM” or “Connect to PX4′′ button

 On a PX4 press the safety switch

 When the prompt appears type Test

 Type motors
The motors will now spin in sequence, each motor will spin for about 1 second at very low t hrottle and then stop. The next motor will start after a 2 or 3 second delay. Please observe the direction of rotation for each motor and also that the motors spin one after another.
The first motor to spin will be the one located directly forward in the case of + configuration, or the first motor to the right of straight forward in the case of X configuration. The motor test will then proceed in a clockwise rotation.
In the case of X8, it will spin the top front

- right motor first, then the bottom front

- r ight, and proceed around with the same pattern.

Octo V will spin the front

- right motor first, and then again, proceed clock

- wise until reaching the front left motor.
After the test pattern is complete, there will be a 4 or 5 second pause before beginning a gain.
When you are satisfied that the motor pattern is correct:

 press any key (the process will not stop until it finishes the current sequence)

 disconnect the main motor battery

 disconnect the usb cablePage | 130Page | 131



## Glossary
NOTE : The glossary is not yet indexed. It is in alphabetical order so just scroll down to find the topic of interest.

2.4 GHz : The frequency used by digital (spread spectrum) radio communications in our applications, including 2.4Ghz RC, Bluetooth and some video transmission equipment. This is a different band than the older 72 MHz band that is used for analog RC communications. To avoid radio frequency conflict is it often a good idea to use 72 MHz radio equipment when you are using 2.4 GHz onboard video transmitters, or use 900 MHz video when using 2.4 GHz RC equipment.

AGL : Altitude above ground level

AHRS : Altitude Heading Reference System. An IMU (see below) plus the code to interpret the output from its sensors to establish a plane’s XYZ and heading orientation.

APM : ArduPilotMega

.

AMA : Academy of Model Aeronautics. The main US model aircraft association. The AMA works closely with the Federal Aviation Administration (FAA) to establish reasonable rules for the use of amateur UAVs. Each AMA chapter and field may have slightly different policies, but it’s possible to fly and test air frame s and some technology on AMA fields without violating the association’s (or FAA/NAS) rules.

Arduino : An open source embedded processor project. Includes a hardware standard currently based on the Atmel Atmega168 microprocessor and necessary supporting hard ware, and a software programming environment based on the C

- like Processing language. Official site is here

. APM ( Autopilot Mega) : Flight Controller providing capabilities for stabilized flight, position maintenance and automated mission (waypoint) path following.

APM: Copter : Rotary

- wing autopilot software for the APM electronics

APM: Plane : Fixed

- wing autopilot software for the APM electronics.

APM: Rover : Ground and water autopilot software for the APM electronics

BEC : Battery Elimination Circuit. A voltage regulator found in ESCs (see below) and as a stand

- alone product. Designed to provide constant 5v voltage for RC equipment, autopilots and other onboard electronics.

Bootloader : Special software code stored in no n

- volatile memory in a microprocessor that can interface with a PC to download a user’s program. Also see Firmware.

COA : Certificate of Authorization. A FAA approval for a UAV flight. See the faa.gov web site for more details and the DIY Drones Regulatory FAQ

.Page | 132

DCM : Direction Cosine Matrix. A algorithm that is a les s processing intensive equivalent of the Kalman Filter. See this for more.
Eagle file : The schematic and PCB design files (and related files that tell PCB fabs how to create the boards ) generated by the free Cadsoft Eagle program. This is the most common standard used in the open source hardware world, although, ironically, it’s not open source software itself. Needless to say, this is not optima l, and the Eagle software is clumsy and hard to learn. One hopes that an open source alternative will someday emerge.

ESC : Electronic Speed Control. Device to control the motor in an electric aircraft. Serves as the connection between the main battery and the RC receiver. Usually includes a BEC, or Battery Elimination Circuit, which provides power for the RC system and other onboard electronics, such as an autopilot.

Firmware : The software or sketch that is loaded into the non

- volatile memory of microproces sor based products. It is called ‘firmware’ because it stays in the non

- volatile memory even if power is removed

– thus ‘non’

– volatile. In the case of the autopilots, it is the ‘program’ or application (App to smart phone users) that determines what the auto pilot does, and how.

FPV : First

- person view. A technique that uses an onboard video camera and wireless connection to the ground allow a pilot on the ground with video goggles to fly with a cockpit view.

FTDI : A standard to convert USB to serial commu nications. Available as a chip for boards that have a USB connector, or in a cable to connected to breakout pins. FTDI stands for Future Technology Devices International, which is the name of the company that makes the chips.

GCS : Ground Control Station. Software running on a computer on the ground that receives telemetry information from an airborne UAV and displays its progress and status, often including video and other sensor d ata. Can also be used to transmit in

- flight commands to the UAV.
Hard Iron magnetic distortion : distortions that arise from magnets or magnetized metals on the airframe that affect the compass. These distortions remain in the same location relative to the compass for all heading orientations. These distortions can be mostly compensated for by adding constant offsets to the values returned from the 3d magnetometer.
HIL (Hardware

- in

- the

- loop simulation) : Doing a simulation where software running on another computer generates data that simulates the data that would be coming from an autopilot’s sensors. The autopilot is running and doesn’t “know” that the data is simulated, so it responds just as it would to real sensor data. Hardware

- in

- the

- loop uses the physical autopilot hardware connected to a simulator, as opposed to simulating the autopilot in software, too. In an “open loop” simulation, the software simulator feeds data to the hardware autopilot; in a “closed loop” simulation, the hardware feeds data back to the software simulator, too.

I2C : A serial bus that allows multiple low speed peripherals, such as sensors, to be connected to a microprocessor. See this for more.Page | 133

IDE : An integrated development environment, such as the Arduino editor/downloader/serial monitor software. Often includes a debugger.

IMU : An inertial measurement unit such as the Ardu P ilot Oil Pan

. Usually has at least three accelerometers (measuring the gravity vector in the x,y and z dimensions) and two gyros (measuring rotation around the tilt and pitch axis). Neither are sufficient by themselves, since accelerometers are thrown off by movement ( i.e. , they are “noisy” over short periods of time), while gyros drift over time. The data from both types of sensors must be combined in software to determine true aircraft attitude and movement to create an AHRS (see above). One technique for doing this is the Kalman filter (see below). Now superseded by Flight controllers which include CPU and sensors in one unit.
Inner loop/Outer loop : Usually used to refer to the stabilization and navigation functions of an autopilot. The stabilization func tion must run in real

- time and as often as 100 times a second (“inner loop”), while the navigation function can run as infrequently as once per second and can tolerate delays and interruptions (“outer loop”).

INS : Inertial Navigation System. A way to calcu late position based on an initial GPS reading followed by readings from motion and speed sensors using dead reckoning. Useful when GPS is not available or has temporarily lost its signal.
ICSP: In Circuit Serial Programmer . A way to load code to a micropro cessor. Usually seen as a six

- pin (two rows of three) connector on a PCB. To use this, you need a programmer, such as this one, that uses the SPI (Serial Peripheral Interface) standard.

Kalman Filter : A relatively complicated algorithm that, in our applications, is primarily used to combine accelerometer and gyro data to provide an accurate description of aircraft attitude and movement in real time. See this for more.

LOS : Line of Sight. See VLOS below.

LiPo : Lithium Polymer battery, aka LiPo

. Variants include Lithium Ion (Li

- Ion) battery. This battery chemistry offers more power and lighter weight than NiMh and NiCad batteries.

MAVLink . The Micro Air Vehicle communications protocol used by the Ardu Copter and Ardu Plane line of autopilots. See here for more info on MAVLink.

MAV : Micro Air Vehicle. A small UAV. More here

.

NMEA : National Marine Electronics Association standard for GPS information. When we refer to “NMEA sentences”, we’re talking about ASCII strings from a GPS module that look like this: $GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,, 47
Oil p an : An Arduino style shield meant to be paired with the ArduPilotMega. Contained the majority of the sensors ( gyros , accelerometers, barometer, etc) that allow the ArduPilotMega to function as anPage | 1 34

autopilot, now superseded by subsequent Flight controllers t hat incorporate CPU and sensors in one board.

OSD : On

- screen display. A way to integrate data (often telemetry information) into the real

- time video stream the aircraft is sending to the ground.

PCB : Printed circuit board. In our use, a specialized board designed and “fabbed” for a dedicated purpose, as opposed to a breadboard or prototype board, which can be used and reused for many projects.

PCM : Pulse Code Modulation: The technique some modern RC transmitters/receivers communicate the RC channels infor mation. It is transmitted digitally using a digital code to represent the channel number, position of the transmitter stick or switch, and sometimes other information. Some modern RC systems also provide digital signals to control digital servos

– typica lly specific to each manufacturer.

PDB : Power Distribution Board. A board used in multi

- copters to distribute power to multiple ESCs.

PIC : Pilot in Command. Refers to a FAA requirement that UAVs stay under a pilot’s direct control if they are flying under the recreational exemption to COA approval. See Line of Sight above. (Not to be confused with the PIC processor series by Microchip)

PID : Proportional/Integral/ Derivative control method. A machine control algorithm that allows for more
accurate sensor

- moti on control loops and less over control . See this for more.

POI : Point of Interest. Designates a spot that a UAV should keep a camera pointed towards.

PPM : Pulse Position Modulation

. The square

- wave pulse train used to transmit multiple channels of information between some RC transmitters and receivers. Some RC receivers provide a PPM output (sometimes referred to as the PPM Sum) which can be used on the APM and PX4. Other receivers convert the PPM signal and only provide PWM signals for each channel.

PWM : Pulse Width Modulation. The square

- wave signals used in RC control to drive servos and speed controllers. There is on e PWM signal for each channel. The width varies from 1000 to 2000 microseconds, depending on the RC manufacturer.
PX4 (PX4FMU and PX4IO) : Flight Controller system providing capabilities for stabilized flight, position maintenance and automated mission (way point) path following.

RTL : Return to Launch. Fly back to the “home” location where the aircraft took off.

SiRF III : The standard used by most modern GPS modules. Includes !SiRF III binary mode, which is an alternative to the ASCII

- based NMEA standard desc ribed above.

Sketch : The program files, drivers and other code generated by the Arduino IDE for a single project.

SVN : Short for the Subversion version

- control repository used by the DIY Drones and other teams for source code.Page | 135

Telemetry System : A two way r adio system to allow flight data to be sent from your aircraft and also to allow control or adjustment information to be sent back to it from a “ground station”, commonly a lap top computer. The 3DR telemetric radio (Here!) is one such system.
Thermopile : An infrared detector. Often used in pairs in UAVs to measure tilt and pitch by looking at differences in the infrared signature of the horizon fore and aft and on both sides . This is based on the fact that there is always an infrared gradient between earth and sky, and that you can keep a plane flying level by ensuring that the readings are the same from both sensors in each pair, each looking in opposite directions. These ha ve been largely displaced by electronic gyros and are no longer in common

use.

UAV : Unmanned Aerial Vehicle. In the military, these are increasingly called Unmanned Aerial Systems (UAS), to reflect that the aircraft is just part of a complex system in the air and on the ground. Ground

based autonomous robots are called Unmanned Ground Vehicles (UGVs) and robot submersibles are called Autonomous Underwater Vehicles (AUVs). Robot boats are called Unmanned Surface Vehicles (USVs).

VLOS : Visual Line of Sight. T he pilot’s ability to see an aircraft from the ground well enough to control it, without the use of artificial visual aids (aside from glasses). Required by FAA regs.

WAAS : Wide Area Augmentation System. A system of satellites and ground stations that prov ide GPS signal corrections, giving up to five times better position accuracy than uncorrected GPS. See this for

more.

Xbee : The commercial name of the recommend ZigBee

- compatible radi o modems commonly used by amateur UAVs. They can be found at sparkfun although remember you also need a board to mount it on like this one from sparkfun or the diy drones store

. ZigBee : A wireless communications standard, which has longer range than bluetooth but lower power consumption than WiFi.Page | 136



## Pitfalls/Lessons Learned

Introduction This page is intended to be a checklist of things to be sure you do at each stage of getting your copter into the air. These things will not prevent you from flying but could cause crashes, so it is important to list them all in one place for easy reading and maintenance.
Please describe the issue in as succinct a manner as possible below, and add a link for further information if necessary.
Assembly

 Twist all your power wires to help minimize electromagnetic interference with your
compass: More Information!

 Check your APM is mounted in the middle of your copter, with the FORWARD arrow pointing straight toward the front in the intended direction of forward flight

 NEVER power camera gimbal servos from the analog output pins, you risk a brownout condition and your APM board rebooting More Information!

 Check each prop is secure before flying: hold the prop in one hand, the arm in the other and try to twist the prop loose. Don’t fly unless the props are secure.
Configuration

 Spin up the propelle rs on the ground and check they are all moving in the correct orientation More Information!

 Check that your motors are connected in the right order by using the CLI mode ‘motors’ command More Information!

 Hold the copter firmly, safely above your head, then spin up the propellers to 1/3rd throttle and test that the copter is trying to keep itself level. It should push back when you tip it over in any direction. Give it some left/right/up/down stick inputs and feel whether the copter is reacting in the correct sense to these inputs

 Check that your copter knows what level is . With the copter on a flat surface connect to Mission Planner and ensure the artificial horizon display shows level

 You should configure Failsafe, otherwise the default behavior is for your copter to shut down and fall to the ground if it loses connection with your radio transmitter. Test this by connecting to Mission Planner, arming your copter (with no battery connected) and turning off your transmitter. You should see it switch to RTL mode when the transmitter is turned off (link required)Page | 137

Flying

 Make s ure you have a GPS lock before flying if you intend to use any auto modes. Even if you’re only flying in Stabilized mode this is a good idea so you can invoke Return To Launch if you get into trouble

 Test RTL before sending your copter off on an auto waypo int flight. This is to check that the compass and GPS are working, and that it knows where home is before heading off on a more complex flight

 Ensure that flight in Stabilize works well before you attempt any more complex flight modes. Ensure loiter works before trying RTL. Ensure RTL works before trying auto.

 Once armed stand 3m

- 6m away from the arming point as when in RTL the copter will be returning to this point.

 When testing more complex flight modes, be ready to switch back to Stabilize mode at any

mo ment if it does anything strange. Stabilize or Acro are the only modes which can save you from a problem with the software or sensors. RTL is a good mode to save you from human error, but relies on the copter being able to locate and fly itself, so this sh ould not be used as an emergency mode if other auto flight modes go wrong

 Be sure you have a way of knowing when your battery is getting low, and land before you have used more than 80% of your battery capacity.