### FY650 Operation and Maintenance Manual

Operation Multicopter Safety Page 2 Pre
‐ Arm Safety Check Page 4 Arming the Motors Page 10 3DR Radio Telemetry Manual Page 12 PixHawk Flight Controller Manual Page 16 GPS and GCS Failsafes Page 30 Battery Failsafe Page 34 Radio Failsafe Page 37 Geofence Failsafe Page 46

Maintenance Installing Mission Planner Page 51 Frame Type Configuration Page 54 RC Transmitter Flight Mode Configuration Page 56 Connect ESC and Motors Page 62 ESC Calibration Page 74 Basic Tuning Page 81 Setting Throttle Page 84 GPS and Compass Module Page 88 Accelerometer Calibration Page 96 Measuring Vibrations Page 100 Radio Calibration Page 105 Co mpass Calibration Page 111

# ! Safety - Read Before Flying ! Your fir s t priority must absolutely be the safety of people ! Multicopters are essentially Flying Lawnmowers!

• ArduCopter is an experimental aircraft running community-created code - Novel and unexpected results are NO T uncommon!
• Crashes can happen, because of pilot error or hardware or software malfunction.
• Especially while you are learning, it is recommended that you avoid, stiff, ultra-sharp carbon fiber props. o Get cheaper more flexible and more breakable plastic ones. o Some carbon fiber props cut better than a Ginsu and while they are almost indestructible, you are not.
• If you are flying anywhere near other people, you are putting them at risk!
• Be sure to maintain safe distances between yourself, and spectators and your copter. o Circumstances will require that you will need to make your own determination of what is a "safe distance" from people and property. o At a minimum, consider: at least 10ft (3m) but not further than 30ft (10m) from you. o Keep all other people, property and obstacles considerably further away from your copter. o Ensure that no one gets between you and your copter. o Spectators should always be a safe distance behind the pilot. o If people intrude beyond what you have determined to be the "safe" area, land immediately and do not take off until they are clear. o 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.
• Always ensure that the battery cable is (NOT) connected to the power distribution board or harness until you are ready to fly. o After landing the first thing you should do is disconnect your battery cable. o Always remove your props while you are testing motors. o Your hands, arms and face and those of your friends will thank you. o When the battery is connected, always assume the motors are armed. o Check with a short throttle pulse. o Don't pick up the model and the radio at the same time, you may bump the throttle. o Do not attempt to fly longer than your batteries safe capacity.

 At a minimum it is very hard on the battery and at worst you will crash destructively.
• The APM and PX4 flight controllers we use incorporate a motor arming safety feature. o Immediately prior to flight after the battery has been connected, the RC transmitters throttle stick needs to be held down and to the right for several seconds to arm the motors. o After landing your first response should be to hold the throttle down and to the left for several seconds to "Disarm" the motors. o Disarm condition can be tested by moving the throttle stick up, if the motors do not move it is dis armed. o Even when disarmed, the throttle stick should always be kept in the full down position except when flying.
• Get used to switching back to Stabilize mode from other modes and reassuming full manual control. o This is the single most important recovery technique (practice it). o Stabilize mode can have Simple mode added to it, but if you do, practice with it till you are proficient. o Do not use any modes other than Stabilize or Stabilize plus Simple until you are VERY comfortable flying.
• Important primary response to a crash, inadequate landing or unknown flight controller state. o The first thing to do is throw a towel over your copters propellers (Propellers may start spinning unexpectedly). o Then immediately disconnect the battery. o A large towel is your most important piece of safety equipment followed by a fire extinguisher and a first aid kit. - - Generally better to use the first one than the last one.
• When testing or flying any of the navigation modes (using GPS): o Ensure that your GPS has "Lock" before arming and takeoff. o Check that your home position on the Mission Planner is in fact correct. o Sometimes GPS's do not report the home position accurately, reboot if not accurate and wait for 8 or more satellites (not just 3D lock) and check again.

## Keep a safe distance between your Copter and People! These t ips can also help protect your multicopter from dama ge.
• Avoid sudden or extreme transmitter control stick deflections o Move th e control sticks in small measured increments and don't "yank" on them. o If the copter is properly calibrated and balanced it should require only small stick inputs to control altitude, direction and speed. o Your copter should be more or less stable on the horizontal plane without any control inputs. o If you are "fighting" the copter, land and fix it - something is not right - Hardware adjustment or software calibration may be required. o Be especially careful of large throttle inputs, as a copter can gain (or lose) altitude very rapidly.
• Because MultiCopters are symmetrical it is especially easy to lose Visual Orientation. o For manual flight modes, maintaining a clear vision of the Copters Orientation (direction it is facing) is the most critical part of successful flight. o Especially while learning it is very important to keep your copter appropriately close to you to aid in maintaining visual orientation. o Generally: more than 10ft (3m) but not further than 30ft (10m) from you. o If the copter gets further than about 100ft (30m) it starts getting difficult to be able to maintain orientation and can easily crash. o If you lose Yaw orientation while flying in Stabilize mode, try only flying forward and using yaw to steer like a car. o It is much better to simply descend and land rather than have an orientation-induced crash or fly away

.  Fly-Aways 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.

 Result: the copter flies further away and crashes or is lost.
• Always have Stabilize mode as the (Go To) one of your 3 options.
• High or unexpected winds or gusts can make flight considerably more difficult. o High winds can prevent forward progress or spin the copter around causing you to become disoriented. o The higher you are, the more likely high winds will be a problem. o Switching to Stabilize mode and landing before you reach your skill limits can help you save your copter.
• Avoid flying at high speed or high altitude until you have gained considerable confidence in both manual and automatic modes.
• When flying around trees or buildings it is very easy to lose visual orientation or even to lose sight of the copter completely. o Gusting winds around objects can also worsen the problem and radio signal loss can also occur. o If your copter is approaching a potentially interfering object, immediately switch to stabilize mode and land or retrieve the copter to your location.
• ArduPilot specific safety modes: RTL, FailSafe and GeoFence. o RTL can provide a safe Return to Launch if it starts to get away from you. o FailSafe and GeoFence can assist you with keeping the copter in a safe proximity. o Do not rely on the above safety modes, always be ready to take control in stabilize and land the copter. o Especially do not rely on the above safety modes to perform maneuvers or training that you would otherwise consider dangerous. o These modes are a supplement to, not a replacement for sound safety practices.
• On your first takeoff after tuning or hardware setup o In stabilize mode advance the throttle very slowly until the copter is almost hovering. o If the copter is trying to flip over turn it off and correct the problem, a motor could be turning the wrong direction, or a wrong direction prop could be installed. o If the copter tries to rotate on it's axis or fly off in some direction the transmitter or RC setup may be incorrect, a motor or ESC may not be performing properly or the props may be installed incorrectly. o When all problems are fixed it should be fairly easy to get the copter to hover a foot or 2 above the ground. o If a stable and stationary hover a foot or 2 above the ground cannot be achieved, land and fix the problem
• When flying FPV "First Person View" (with a video camera), Set modes to: STABILIZE, SIMPLE, and RTL. o Ensure RTL is working properly before using FPV, o Use Stabilize mode to fly FPV and If you lose FPV video switch to Simple or RTL to get back.
• Make sure your battery can't fall out, use a Velcro Strap to hold it in place.Copter includes a suite of Pre-arm Safety Checks which will pre vent the vehicle from arming if any of a fairly large number of issues are discovered before ta ke-off including missed calibration, configuration or bad sensor data. These checks hel p prevent crashes and fly-aways but they can also be disabled if necessary. 

### ArduCopter 3.0 Pre-Arm Checks

Contents [ hide ] ArduPilot > Copter > Pre-Arm Safety Check 

# Pre-Arm Safety Check Copter

English1 Recognising which Pre-Arm Check has failed using the GCS 2 Failure messages 3 Disabling the Pre-arm Safety Check 

# Recognising which Pre-Arm Check has failed using the GCS The pilot will notice a pre-arm check failure because he/she wi ll be unable to arm the copter and the LED will be flashing yellow.  To determine exactly whic h check has failed: 1. Connect the Flight Controller to the ground station using a USB cable or Telemetry

. 2. Ensure the GCS is connected to the vehicle (i.e. on Mission Plannerand push the “Connect” button on the upper right). 3. Turn on your radio transmitter and attempt to arm the vehicle (regular procedure using throttle down, yaw right) 4. The first cause of the Pre-Arm Check failure will be displayed in red on the HUD window 

# Failure messages RC failures (i.e. transmitter/receiver failures): RC not calibrated : the radio calibration has not been performed.  RC3_MIN and RC3_MAX must have been changed from their default values (1100 and 1900) and for channels 1 to 4, the MIN must be less than 1300 and the MAX gre ater than 1700. Barometer failures: Baro not healthy : the barometer sensor is reporting that it is unhealthy which is normally a sign of a hardware failure. Alt disparity : the barometer altitude disagrees with the inertial navigation (i.e. Baro + Accelerometer) altitude estimate by more than 2 meters.  This m essage is normally shortlived and can occur when the flight controller is first plugged in or if it receives a hard jolt (i.e. dropped suddenly).  If it does not clear the accelerometers may need to be calibrated or there may be a barometer hardware issue.Compass failures: Compass not healthy : the compass sensor is reporting that it is unhealthy which i s a sign of a hardware failure. Compass not calibrated : the compass(es) has not been calibrated .  the COMPASS_OFS_X, Y, Z parameters are zero or the number or type o f compasses connected has been changed since the last compass calibration w as performed. Compass offsets too high : the primary compass’s offsets length (i.e. sqrt(x^2+y^2+z^2) ) are larger than 500.  This can be caused by metal objects being placed too close to the compass.  If only an internal compass is being used (not recomm ended), it may simply be the metal in the board that is causing the large offsets and th is may not actually be a problem in which case you may wish to disable the compass check

. Check mag field : the sensed magnetic field in the area is 35% higher or  lowe r than the expected value.  The expected length is 530 so it’s > 874 or < 185.  Magnetic field strength varies around the world but these wide limits mean it’s more li kely the compass calibration has not calculated good offsets and should be repeated. Compasses inconsistent : the internal and external compasses are pointing in differen t directions (off by >45 degrees).  This is normally caused by th e external compasses orientation (i.e. COMPASS_ORIENT parameter) being set incorrect ly. GPS related failures: GPS Glitch : the GPS is glitching and the vehicle is in a flight mode that requires GPS (i.e. Loiter, PosHold, etc) and/or the circular fence is enabled. Need 3D Fix : the GPS does not have a 3D fix and the vehicle is in a fligh t mode that requires the GPS and/or the circular fence is enabled. Bad Velocity : the vehicle’s velocity (according to inertial navigation sys tem) is above 50cm/s.  Issues that could lead to this include the vehicle act ually moving or being dropped, bad accelerometer calibration, GPS updating at below t he expected 5hz. High GPS HDOP : the GPS’s HDOP value (a measure of the position accuracy) is above 2.0 and the vehicle is in a flight mode that requires GPS and/o r the circular fence isenabled.  This may be resolved by simply waiting a few minutes, moving to a location with a better view of the sky or checking sources of GPS interferenc e (i.e. FPV equipment) are moved further from the GPS.  Alternatively the check can be rel axed by increasing the GPS_HDOP_GOOD parameter to 2.2 or 2.5.  Worst case the pilot ma y disable the fence and take-off in a mode that does not require the GPS (i.e. Stab ilize, AltHold) and switch into Loiter after arming but this is not recommended. Note: the GPS HDOP can be readily viewed through the Mission Pl anner’s Quick tab as shown below.

INS checks (i.e. Acclerometer and Gyro checks): INS not calibrated : some or all of the accelerometer’s offsets are zero.  The accelerometers need to be calibrated

. Accels not healthy : one of the accelerometers is reporting it is not healthy whi ch could be a hardware issue.  This can also occur immediately after a firm ware update before the board has been restarted. Accels inconsistent : the accelerometers are reporting accelerations which are dif ferent by at least 1m/s/s.  The accelerometers need to be re-calibrated or there is a hardware issue. Gyros not healthy : one of the gyroscopes is reporting it is unhealthy which is likely a hardware issue.  This can also occur immediately after a firmwa re update before the board has been restarted. Gyro cal failed : the gyro calibration failed to capture offsets.  This is mos t often caused by the vehicle being moved during the gyro calibration (when red a nd blue lights are flashing)in which case unplugging the battery and plugging it in again w hile being careful not to jostle the vehicle will likely resolve the issue.  Sensors hard ware failures (i.e. spikes) can also cause this failure. Gyros inconsistent : two gyroscopes are reporting vehicle rotation rates that dif fer by more than 20deg/sec.  This is likely a hardware failure or caus ed by a bad gyro calibration. Board Voltage checks: Check Board Voltage : the board’s internal voltage is below 4.3 Volts or above 5.8 Volts. If powered through a USB cable (i.e. while on the bench) this c an be caused by the desktop computer being unable to provide sufficient current to the flight controller – try replacing the USB cable. If powered from a battery this is a serious problem and the pow er system (i.e. Power Module, battery, etc) should be carefully checked before flying

. Parameter checks: Ch7&Ch8 Opt cannot be same : Ch7 and Ch8 auxiliary switches are set to the same option which is not permitted because it could lead to confusio n. Check FS_THR_VALUE : the radio failsafe pwm value has been set too close to the throttle channels (i.e. ch3) minimum. Check ANGLE_MAX : the ANGLE_MAX parameter which controls the vehicle’s maximum lean angle has been set below 10 degrees (i.e. 1000) or above 8 0 degrees (i.e. 8000). ACRO_BAL_ROLL/PITCH : the ACRO_BAL_ROLL parameter is higher than the Stabilize Roll P and/or ACRO_BAL_PITCH parameter is higher than the Stabi lize Pitch P value. This could lead to the pilot being unable to control the lean a ngle in ACRO mode because the Acro Trainer stabilization would overpower the pilot’s input. 

# Disabling the Pre-arm Safety CheckIf you are confident that the pre-arm check failure is not a re al problem you can disable the checks by: Connecting your Flight Controller to the Mission Planner Go to Mission Planner’s Config/Tuning >> Standard Params screen set the Arming Check drop-down to “Disabled” or one of the “Ski p” options which more effectively skips the item causing the failure. Push the “Write Params” button Ideally however you should determine the cause of the pre-arm f ailure and if it can be resolved, return the Arming Check parameter back to “Enabled”
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Contents [ hide ] 1 Arming the motors 2 Disarming the motors 

# 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. The pre-arm checks will run automatically and if any problems are found an APM2.x will double blink the red arming light, on a Pixhawk the RGB led wil l blink yellow.  Please refer to this page

. 4. Check that your flight mode switch is set to Stabilize, ACRO, AltHold or Loiter. 5. If using a PX4, press the safety button until the light goes solid. 6. If you are planning on using the autopilot (i.e. Loiter, RTL, Drift, Auto or Guided modes) you should wait for 30 seconds after the GPS has gotten 3d lock.  T his will give the GPS position time to settle.  On APM2 the GPS lock is indicated by the blue LED going solid.  On an Pixhawk the RGB LED will blink green. 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 i t re-initialises the gyros and barometer.  Do not hold the rudder right for too long (>15 seco nds) or you will begin the AutoTrim feature. ArduPilot > Copter > Arming the motors 

# Arming the motors Copter

EnglishNote:
Note: 8. Once armed, the red arming light should go solid and the propellers will begin to spin slowly.  The speed they spin can be adjusted with the MOT_SPIN_ ARMED parameter. 9. Raise the throttle to take-off. You can only arm or disarm in Stabilize, ACRO, AltHold and Loit er mode. If you leave the throttle at minimum for 15 seconds while in an y of the above modes 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, ACRO, AltHold or Loiter 2. Hold throttle at minimum and rudder to the left for 2 seconds 3. The red arming light should start flashing on the APM2.  On the Pixhawk the RGB LED will start flashing green. 4. If using a PX4, press the safety button until the led begins flashing 5. Disconnect the Lipo battery 6. Turn off your transmitter
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.

# 3DR RADIO V2 QUICK START GUIDE

PARTS GETTING STARTED 3DR Radios provide an air-to-ground data link between the autopilot and your ground station laptop or tablet. Follow this guide to install the radios on your plane, copter, or rover. 3DR Radios arrive ready to use. Just mount and connect to view real-time data from your drone.

Android adapter cable

6-wire Pixhawk connector cable Micro-USB cable Two 3DR Radios in 915 or 433 mHz Attach the antennas, and use either radio as an air or ground module.

6-to-5-position APM and PX4 connector cable

### MOUNT CONNECT TO AUTOPILOT
Connect to the APM 2.5 or 2.6 telemetry port using the 6-to-5-position cable.

Connect to the PX4 I/O telemetry port using the 6-to-5-position cable. Connect to the Pixhawk telemetry port using the 6-wire cable.

Mount the air module securely to your vehicle keeping the antenna clear of any propellers or moving components. Ensure that the antenna is oriented vertically for maximum range. 

### CONNECT TO MISSION PLANNER

Use the micro-USB cable to connect the ground module to your laptop. In Mission Planner and APM Planner ground station applications, select the communication option that shows COM , set the rate to 57600 , and select Connect . The radio will not connect unless the vehicle is powered. Use the Flight Data screen to view your vehicle’s status and control missions in flight.

LEARN MORE a bout installing a mission planner application for your laptop or tablet and interacting with the autopilot using 3DR Radios (including retrieving flight data logs) at planner.ardupilot.com

. Mission PlannerTIPS Orient the ground radio antenna vertically for maximum range. 

### CONNECT TO TABLET Connect the ground module to your tablet using the Android adapter cable. Connect the colored end to the tablet and the black end to the radio. In DroidPlanneror Andropilot , select Connect

.

DroidPlanner Flight Data screen View the strength of the radio signal in the mission planner’s flight data screen.



### SETTINGS To change the radio settings in the mission planner, connect the radio to your computer, but do not select Connect. Radios can only be configured while unconnected to MAVLink. Select Initial Setup , 3DR Radio , and Load Settings to configure the radios.

All settings should be the same for both modules. Ensure that the Net ID setting is identical on each radio to enable pairing. Select Save Settings to apply settings. For flying with friends, make sure your Net IDs do not conflict. Use the configuration options on this screen to apply the correct airspace regulation requirements for your area. You are responsible for complying with all airspace regulations in your area, including frequency restrictions, power levels, and licenses. For more information on configuring 3DR Radios to comply with local regulations, visit the online documentation at goo.gl/Tsrksf

.

### SPECIFICATIONS

3DR Radio Guide V1 © 3D Robotics, Inc. 28 October 2013 

### SUPPORT For more information about mission planner applications and APM firmware, visit ardupilot.com . For online documentation of 3DR Radios, visit goo.gl/Tsrksf

. For customer support, contact us at help@3drobotics.com or call our support line at +1 (858) 225-1414

. Processing 100 mW maximum output power (adjustable) -117 dBm receive sensitivity Based on HopeRF’s HM-TRP module RP-SMA connector 2-way full-duplex communication through adaptive TDM UART interface Transparent serial link MAVLink protocol framing Frequency Hopping Spread Spectrum (FHSS) Configurable duty cycle Error correction corrects up to 25% of bit errors Open-source SIK firmware Configurable through Mission Planner & APM Planner Features Interchangeable air and ground modules 915 or 433 mHz Micro-USB port 6-position DF13 connector

Power Supply voltage: 3.7-6 VDC (from USB or DF13) Transmit current: 100 mA at 30 dBm Receive current: 25 mA Serial interface: 3.3 V UART Dimensions 26.7 cm x 55.5 cm x 13.3 cm (without antenna) 3

4

5 1 Micro-USB port 2 6-wire cable connector 3 Antenna 4 Frequency 5 LED indicator 1 2 

### RADIO DESCRIPTION LED MEANINGS

Solid green Link established with paired radio Blinking green Searching for paired radio Blinking red Transmitting data Solid red Firmware update mode

## AUTOPILOT



# QUICK START GUIDE

### PARTS

1 Pixhawk 2 Buzzer 3 Safety switch 4 Micro-SD card and adapter 5 Micro-USB cable 6 Six-wire cable x2 7 Power module 8 I 2 C splitter module 9 Four-position I 2 C splitter cable 10 Three-wire servo cable 11 Mounting foam 1 2 3 4 5 7

8 11



### MOUNT Use the provided foam to mount Pixhawk as close as possible to your vehicle’s center of gravity. Make sure to orient the board with the arrow pointing forward.

Vehicle front Attach the foam squares to the corners of the board. 

### GETTING STARTED With the help of APM firmware, Pixhawk turns any RC plane, copter, or rover into a full-featured personal drone. Once you have a fully-assembled frame, follow this guide to install Pixhawk. 6

9 10

1 Mount 2 Connect 3 Load firmware 4 Calibrate 

# 1

### CONNECT

(Required) Connect the buzzer and safety switch.

(Optional) Connect a 3DR Radio to Pixhawk’s Telem port using the 6-wire cable provided with your 3DR Radio Kit to receive data and communicate with the autopilot in flight. (GPS or GPS+Compass required) Connect a 3DR GPS+Compass to provide the autopilot with positioning data during flight. This kit includes a 6-wire cable to connect the GPS ports. Connect the MAG to the I 2 C port using the 4-wire cable provided with the 3DR GPS+Compass. (Required) Connect the 3DR Power Module to the Power port using the 6-wire cable to direct power from your lithium polymer

(LiPo) battery to the autopilot.

(Optional) The I 2 C splitter expands the I 2 C port to allow up to four additional peripherals to connect to Pixhawk. Use the 4-wire cable to connect the I 2 C splitter and add a compass module, external LED, digital airspeed sensor, or other peripherals to your vehicle. 

# 2Connect the ground (-), power (+), and signal (S) wires to the RC pins using the provided 3-wire servo cable.

For a Spektrum DSM, DSM2, or DSM-X Satellite RC receiver, connect to the SPKT/DSM port. 

### CONNECT RADIO CONTROL FOR PPM RC RECEIVERS AND FUTABA S.BUS RECEIVERS

FOR SPEKTRUM SATELLITE RECEIVERS

FOR PWM RECEIVERS
Purchase a PPM Encoder module to connect a PWM RC receiver to Pixhawk at store.3dr.com

. LOAD SD CARD INTO PIXHAWK If the SD card is not preloaded into Pixhawk, insert the micro-SD card into the slot at the bottom end of the board.

For a complete list of RC systems compatible with Pixhawk, visit the APM wiki page here

.

### LOAD FIRMWARE
APM firmware is the brains of your autopilot operation and must be installed before using Pixhawk. To load firmware onto Pixhawk, install a mission planner application on your ground station computer. Choose either Mission Planner (Windows) or APM Planner for (Windows, OS X, and Linux). Both applications are available for free download from ardupilot.com

. For rovers, connect the throttle and steering wires to the main output signal pins. Pin 3 = Throttle Pin 4 = Steering

Mission planner f irmware FOR COPTERS

FOR PLANES

FOR ROVERS Connect each signal wire from the PDB to the main output signal (S) pins by motor number. Connect one wire for each motor to the corresponding pin. Pin 1 = Motor 1 Pin 5 = Motor 5 Pin 2 = Motor 2 Pin 6 = Motor 6 Pin 3 = Motor 3 Pin 7 = Motor 7 Pin 4 = Motor 4 Pin 8 = Motor 8

For planes, connect the control channel wires to the main output signal pins. Pin 1 = Aileron Pin 2 = Elevator Pin 3 = Throttle Pin 4 = Rudder 

### CONNECT OUTPUTS



# 3Download Mission Planner (Windows)


### Mission Planner « Downloads Sort by: Title | Hits | Date

■ MissionPlanner - Installer Select the installer package to download. Ardupilot.com Downloads Mission Planner

After selecting the correct file, read the safety information and select Download. Open the file to run the setup wizard. Proceed through any security warnings, and install all suggested drivers. When the installation is complete, open the application, and connect Pixhawk to your computer using the micro-USB cable. Your computer will automatically install the correct drivers. Do not select Connect at this time; Pixhawk can only load firmware while unconnected to Mavlink. Download APM Planner (Windows, OS X, and Linux)


### APM Planner 2.0 « Downloads Sort by: Title | Hits | Date

■ APM Planner 2.0 Mac

■ APM Planner 2.0 Windows

■ APM Planner 2.0 Linux Select your platform to download. Ardupilot.com Downloads APM Planner 2.0

INSTALL PLANNERWhen prompted, follow the directions to load the firmware. Once the status bar shows that the download is complete, power cycle the board by disconnecting and reconnecting the USB. If you hear a musical tone, your firmware installation is complete. If you hear a series of tones followed by three beeps, disconnect the USB and reconnect while holding down the safety button. Upon restart, listen for a series of tones followed by two beeps indicating that your firmware has loaded successfully.

beep BEEP beep... BEEP BEEP 

#  Pixhawk needs your attention: beep BEEP beep... BEEP BEEP BEEP Everything is OK: musical tone 

#  Select Initial Setup, Install Firmware , and select your vehicle.



### CALIBRATE
With Pixhawk connected to your computer, select the communication option from the drop-down menu for PX4 FMU , set the rate to 115200 , and select the Connect icon. Select Initial Setup and Mandatory Hardware to access the calibration wizards.

Remove propellers before performing calibration. 

# ! 

# 4SELECT FRAME TYPE (COPTERS ONLY)

CALIBRATE COMPASS

Select the options to enable the compass; to allow automatic declination calculation; and to specify Pixhawk. Select Live Calibration to launch the wizard, and follow the prompts.

Show Me videos demonstrating live calibration techniques at 3dr.com/learn

.

For copter, select your frame orientation.CALIBRATE ACCELEROMETER

SELECT FLIGHT MODES 

### 4 5

6 RC CALIBRATION

left stick

right stick Select Accel Calibration , check the box for AC 3.0+, select Calibrate , and follow the prompts to calibrate Pixhawk’s accelerometer. Make sure to wait a couple of seconds before and after changing the positions of the vehicle.

Select Radio Calibration to teach Pixhawk to work with your RC transmitter. Turn on your transmitter, select Calibrate Radio , and move all sticks and switches to their extreme positions. Select Click when Done once the red bars are set for all available channels.

Move each switch on your transmitter to its available positions. The mission planner will indicate the currently selected position with green highlighting. Select a mode for each switch position, and select Save Modes to assign.

### LED MEANINGS
Flashing red and blue: initializing. Please wait.
Double flashing yellow: error. System refuses to arm.
Flashing blue: disarmed, searching for GPS. Autonomous, loiter, and return-to-launch modes require GPS lock. Flashing green: disarmed, GPS lock acquired. Ready to arm. Quick double tone when disarming from the armed state.
Solid green plus single long tone: armed and ready to fly!
Flashing yellow: RC failsafe activated.

Flashing yellow plus quick repeating tone: battery failsafe activated.

Flashing yellow and blue plus high-high-high-low tone: GPS glitch or GPS failsafe activated.

Quick, constant blinking: performing system check. Please wait.

Solid: ready to arm. Proceed to the arming procedure. Intermittent blinking: system ready. Press the safety button to activate. 

### SAFETY SWITCH MEANINGS

Learn more about LED meanings and buzzer tones at 3dr.com/learn

.1

2 3 4 5

6 7 8

9 10 11 12

13 14 15 1 Spektrum DSM receiver 2 Telemetry (radio telemetry) 3 Telemetry (on-screen display) 4 USB 5 SPI (ser i al peripheral interface) bus 6 Power module 7 Safety switch button 8 Buzzer 9 Serial 10 GPS module 11 CAN (controller area network) bus 12 I 2 C splitter or compass module 13 Analog to digital converter 6.6 V 14 Analog to digital converter 3.3 V 15 LED indicator 

### PORTS

1 2

3 4
1 Input/output reset button 2 SD card 3 Flight management reset button 4 Micro-USB port
1 2

ground power signal

1 Radio control receiver input 2 S.Bus output 3 Main outputs 4 Auxiliary outputs 3 4Processor 32-bit ARM Cortex M4 core with FPU 168 Mhz/256 KB RAM/2 MB Flash 32-bit failsafe co-processor Sensors ST Micro 16-bit gyroscope ST Micro 14-bit accelerometer/magnetometer MEAS barometer MPU6000 accelerometer/magnetometer Power Ideal diode controller with automatic failover Servo rail high-power (7 V) and high-current ready All peripheral outputs over-current protected, all inputs ESC protected Interfaces 5x UART serial ports, 1 high-power capable, 2x with HW flow control Spektrum DSM/DSM2/DSM-X Satellite input Futaba S.BUS input and output PPM sum signal RSSI (PWM or voltage) input I 2 C, SPI, 2x CAN, USB 3.3 and 6.6 ADC inputs Dimensions Weight 38 g (1.3 oz) Width 50 mm (2.0”) Height 15.5 mm (.6”) Length 81.5 mm (3.2”) 

### SPECIFICATIONS IMPORTANT NOTE

SUPPORT For more information about Pixhawk and other documentation, visit 3dr.com/learn

. For more instruction on using APM firmware and planner software, visit ardupilot.com

. For customer support, contact us at help@3dr.com or call our support line at +1 (858) 225-1414 Monday through Friday, 8 am to 5 pm, PST. Please note that these instructions describe basic setup for Pixhawk and do not represent the complete set of configuration procedures required to build a copter, plane, or rover. For more information on ESC calibration, battery monitoring, failsafes, mode descriptions, and more, visit ardupilot.com . Do not operate your vehicle without a complete understanding of the online instructions.Operating a powered vehicle of any kind can be a lot of fun, but it carries certain inherent risks. Regulations governing the use of powered vehicles, including aircraft, vary from locale to locale, even within the same country or district. It is your responsibility to ensure that you understand and comply with all local laws and regulations. Safety basics:

• Never operate the vehicle or software in a way that could be dangerous to you, other people, or property. • Always keep propeller arcs free of objects and body parts while the vehicle is live. • Keep in mind that software and hardware failures happen. Although we design our products to minimize

such issues, you should always operate with the understanding that a failure could occur at any time and without warning. Accordingly, you should take the appropriate precautions to minimize danger in case of product failure. • Never use the software or hardware for manned vehicles. • Always operate within local laws and regulations. • Do not operate the aircraft if you are under the age of 18. Additional safety information:

• Be sure to maintain safe distances between people and your aircraft. • Never operate your aircraft if your ability to do so with the utmost attention to safety is impaired in any

way. Do not operate your aircraft while tired, under the influence of drugs or alcohol, or otherwise unable to operate it with the highest attention to safety. • Environment conditions can change rapidly and can make operation difficult. If this occurs, land your aircraft

and discontinue use immediately. Do not operate your aircraft if operating conditions are not ideal. This includes, but is not limited to, rain, snow or excessive wind. • Always ensure the battery cable is disconnected from the aircraft until you are ready to fly, and ensure that

your batteries are fully charged prior to use. • Always turn on the transmitter and ensure the throttle stick is all the way down before connecting the

battery. • After landing, disarm your vehicle immediately and disconnect the battery cable. • Do not turn off the transmitter until after you have disconnected the battery. • Always remove the propellers while testing the motors. • When the battery is connected, always assume the vehicle is live and the motors are armed. • Do not attempt to fly longer than the battery’s safe capacity. • Do not operate the vehicle with excess weight attached. • Ensure that all vehicle components are well maintained before each flight. Ensure that components are

firmly attached and operating properly. • Replace any worn or damaged components before each flight. Never operate with any damaged or worn

components. • SAFETY IS THE FIRST PRIORITY. Take all precautions necessary to ensure your own safety as well as the

safety of other people and property. 

### SAFETY

### DISCLAIMER

THE LIMITED WARRANTIES APPLICABLE TO 3D ROBOTICS-BRANDED HARDWARE CAN BE FOUND AT WWW.3DROBOTICS.COM/TERMS/ AND CAN BE REFERENCED IN FULL AT THAT URL. 3D ROBOTICS RESERVES THE RIGHT TO UPDATE THE WARRANTIES AT ANY TIME WITHOUT EXPRESS NOTICE. 3D ROBOTICS MAKES NO OTHER WARRANTIES FOR 3D ROBOTICS-BRANDED PRODUCTS, AND MAKES NO WARRANTIES WHATSOEVER FOR SERVICE, SOFTWARE, MAINTENANCE OR SUPPORT FOR NON-3D ROBOTICS-BRANDED PRODUCTS. SUCH PRODUCTS, SOFTWARE, SERVICES, MAINTENANCE OR SUPPORT IS PROVIDED BY 3D ROBOTICS “AS IS” AND ANY THIRD-PARTY WARRANTIES, PRODUCTS, SOFTWARE, SERVICES, MAINTENANCE OR SUPPORT ARE PROVIDED BY THE ORIGINAL MANUFACTURER OR SUPPLIER, NOT BY 3D ROBOTICS. 3D ROBOTICS MAKES NO EXPRESS WARRANTIES EXCEPT THOSE STATED IN 3D ROBOTICS’ APPLICABLE WARRANTY IN EFFECT ON THE DATE OF THE INVOICE, PACKING SLIP OR ACKNOWLEDGEMENT. 3D ROBOTICS OFFERS THE HARDWARE AS-IS AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE HARDWARE, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, OR THE ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OF ABSENCE OF ERRORS, WHETHER OR NOT DISCOVERABLE. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF IMPLIED WARRANTIES, SO SUCH EXCLUSION MAY NOT APPLY TO YOU. EXCEPT TO THE EXTENT REQUIRED BY APPLICABLE LAW, IN NO EVENT WILL 3D ROBOTICS BE LIABLE TO YOU ON ANY LEGAL THEORY FOR ANY SPECIAL, INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES ARISING OUT OF THE USE OF THE HARDWARE. 3D ROBOTICS ACCEPTS NO LIABILITY FOR DAMAGE(S) OR INJURIES INCURRED DIRECTLY OR INDIRECTLY FROM THE USE OF THIS PRODUCT. SOFTWARE IS SUBJECT TO THE SEPARATE SOFTWARE LICENSE AGREEMENT ACCOMPANYING OR MADE AVAILABLE TO YOU IN CONNECTION WITH THE SOFTWARE. A PORTION OF THE SOFTWARE MAY CONTAIN OR CONSIST OF OPEN-SOURCE SOFTWARE, WHICH YOU MAY USE UNDER THE TERMS AND CONDITIONS OF THE SPECIFIC LICENSE UNDER WHICH THE OPEN-SOURCE SOFTWARE IS DISTRIBUTED. YOU AGREE THAT YOU WILL BE BOUND BY ANY AND ALL SUCH LICENSE AGREEMENTS, AND THAT YOUR USAGE OF THIS PRODUCT INDICATES YOUR ACCEPTANCE OF THOSE AGREEMENTS. TITLE TO SOFTWARE REMAINS WITH THE APPLICABLE LICENSOR(S). IN NO EVENT WILL 3D ROBOTICS BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE.

Pixhawk Kit User Guide V8 © 3D Robotics, Inc. 20 March 2014This pages covers the set-up and testing of the GPS and Ground Station Control (GCS) failsafes. Note that Copter has 2 other failsafes : Radio and Battery

. Contents [ hide ] 1 GPS Failsafe 2 Ground Control Station Failsafe 

## GPS Failsafe The GPS Failsafe is enabled by default but you can enable or di sable it on the Mission Planner’s Standard Parameter List, by set the FS_GPS_ENABLE par ameter to 0 (Disable) or 1 (Land) or 2 (switch to AltHold).  It is highly recommended to leave it enabled and no known reason why it should ever be disabled. If you lose GPS lock or experience a GPS Glitch for 5 seconds w hile in a mode that requires the GPS (Auto, Guided, Loiter, RTL, Circle, Position or Drift) mode it will initiate a Land (or AltHold if FS_GPS_ENABLE is set to 2). ArduPilot > Copter > GPS and GCS Failsafes 

# GPS and GCS Failsafes Copter

EnglishBelow is a video of a simulated GPS Failure resulting in the co pter Landing. 

### GPS failsafe testing with AC 2.9.2

Additional information on the GPS failsafe and Glitch protectio n can be found here

. 

## Ground Control Station FailsafeNote: 

## Ground Control Station Failsafe In Mission Planner’s Advanced Parameter List, set the FS_GCS_EN ABLE 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 w ith 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 motors – if you are in stabilize or acro mode and your t hrottle is zero RTL – if you have a GPS lock and are more than 2 meters from yo ur home position LAND – if you have no GPS lock or are within 2 meters of home Continue with the mission – if you are in AUTO mode and have se t the GCS Failsafe Options to 2 (Enabled_continue_in_auto_mode). If the failsafe clears (contact with the ground station is rest ored) the copter will remain in it’s 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, yo u 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.

All Failsafe Parameters can also be observed or set from the Ad vanced Parameter List.
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Tip: This article explains how to setup and test the battery failsaf e.

Contents [ hide ] 1 Overview 2 When the failsafe will trigger 3 What will happen 4 Setting up the battery failsafe 5 Low Battery warning (even with failsafe disabled) 

# Overview The battery failsafe can be set-up to automatically trigger an RTL or LAND when the vehicle battery voltage or estimated remaining power has crossed a conf igurable threshold. To use this failsafe the vehicle must have a Power Module or other voltage and (optionally) current monitor

. Copter also supports Radio , GPS and Ground Station Control failsafes. 

# When the failsafe will trigger If enabled and set-up correctly the battery failsafe will trigg er if the main battery: voltage drops below 10.5 volts (configurable) for more than 10 seconds ArduPilot > Copter > Battery Failsafe 

# Battery Failsafe Copter

Englishremaining capacity falls below the configurable Reserved MAH 

# What will happen When the failsafe is triggered one of the following will happen : Nothing if the vehicle is already disarmed Disarm motors if the vehicle is in Stabilize or Acro mode and the throttle i s at zero OR the vehicle is landed Return-to-Launch (RTL) if the FS_BATT_ENABLE param is set to “2” (“RTL”) OR the vehicle is in AUTO mode, has a GPS lock and are at least 2 meters from your home position Land in all other cases 

# Setting up the battery failsafe Setup the power module as described in the Power Modules section of this wiki including setting the totally battery capacity if using a current monitor On the INITIAL SETUP | Mandatory Hardware | Failsafe page: set the “Low Battery” threshold voltage (i.e. 10.5 volts) set the “Reserved MAH” or leave as “0” if the failsafe should n ever trigger based on estimated current consumed.  “600” would be an appropriate numb er to cause the vehicle to LAND or RTL when only 20% of a 3000mAH  battery remains. select the desired behavior as “Land” or “RTL” (Note: the place ment of the drop-down is confusing but this will be corrected in a future version of the mission planner)

# Low Battery warning (even with failsafe disabled) Even if the battery failsafe is not enabled (i.e. FS_BATT_ENABLE = 0 ) the “Low Battery” voltage threshold and “Reserved MAH” numbers are used to issue a batter y warning. This will result in: “Low Battery!” message appearing on the ground stations HUD (if using telemetry) Loud beeping if a buzzer is attached Flashing LEDs The only way to disable this warning completely is to set the “ Low Battery” voltage and “Reserved MAH” values to zero.
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Note: Copter supports Return-To-Launch in cases where contact between the Pilot’s RC transmitter and the flight controller’s receiver is lost.  This page explai ns this failsafe’s setup and testing. Note the “Radio failsafe” was previously called “Throttle fails afe” because of the way in which some receivers use the throttle channel to signal the loss of c ontact.

Copter also support Battery , GPS, Ground Station and EKF/DCM failsafes

. Contents [ hide ] 1 When the failsafe will trigger 2 What will happen 3 Receiver and flight controller set-up 3.1 Set-up for low-throttle method 3.2 Set-up for No-Signal method 4 Testing 5 Using the receiver to set the flight mode (not recommended) ArduPilot > Copter > Radio Failsafe 

# Radio Failsafe Copter

English6 Warning to Copter 3.1.5 and FRSky receiver users and users of other receivers that modify channel 5 during a failsafe event 

## When the failsafe will trigger If enabled and set-up correctly the radio failsafe will trigger if: The pilot turns off the RC transmitter The vehicle travels outside of RC range (usually at around 500m ~ 700m) The receiver loses power (unlikely) The wires connecting the receiver to the flight controller are broken (unlikely).  Note: with APM2 only the ch3 connection between receiver and flight contro ller will trigger the failsafe. 

## What will happen When a radio failsafe is triggered one of the following will ha ppen: Nothing if the vehicle is already disarmed Motors will be immediately disarmed if the vehicle is landed OR in stabilize or acro mode and the pilot’s throttle is at zero Return-to-Launch (RTL) if the vehicle has a GPS lock and is more than 2 meters from t he home position LAND if the vehicle has: no GPS lock OR is within 2 meters of home OR the FS_THR_ENABLE parameter is set to “Enabled Always Land” Continue with the mission if the vehicle is in AUTO mode and the FS_THR_ENABLE parameter is set to “Enabled Continue with Mission in Auto Mode ”. If the failsafe clears (i.e. transmitter and receiver regain co ntact) 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, the ve hicle was in Loiter when the failsafe occured and the flight mode was automatically changed to RTL, even after the transmitter and receiver regained contact, the vehicle would re main in RTL.  If the pilot wished to re-take control in Loiter he/she would need to change your f light mode switch to another position and then back to Loiter. 

## Receiver and flight controller set-up

## Receiver and flight controller set-up By default, a newly purchased receiver will be set-up to simply hold all channels at their last known position when the receiver and transmitter lose contact. This is not good because the flight controller has no way to know that the Pilot has lost co ntrol of the vehicle.  Instead the receiver must be set-up to signal to the flight controller it h as lost contact and there are two ways that it can do this (the method depends upon the receiver) : “Low-Throttle” method – the receiver pulls the throttle channel (normally channel 3) to a value below the bottom of it’s normal range (normally below 975 ).  This method is used by Futaba systems and many older systems. “No Signal” method – the receiver stops sending signals to the flight controller.  This is the preferred method and is how most modern FrSky receivers operate

. Each brand of Transmitter/Receiver is slightly different so ple ase refer to your transmitter’s user manual to determine which method is available and how to set it up. 

### Set-up for low-throttle method Futaba T7C Failsafe SetupAbove is the setup method for a Futaba T7C Transmitter with R61 7FS or TFR4-B receiver which uses the “low throttle” method. With the LiPo battery disconnected: Connect your flight controller to the mission planner and selec t Initial Setup >> Mandatory Hardware >> Failsafe. Set the Failsafe Options to one of the three options: “Enabled always RTL” to force the vehicle to always RTL even if flying a mission in AUTO mode “Enabled Continue with Mission in AUTO” to allow the vehicle to continue with missions even if it takes the vehicle outside of RC range (not recommended).  In all other cases the vehicle will RTL. “Enable always LAND” to force the vehicle to Land immediately i f it loses RC contact Set the “FS Pwm” value to be: 

### at least 10 PWM higher than your Channel 3’s PWM value when the throttle stick is fully down and the transmitter is off at least 10 lower than your channel 3’s PWM value when the thro ttle stick is fully down and the transmitter is on above 910

### Set-up for No-Signal method FrSky D4R-II receiver failsafe setup with AC3.1 on PixhawkAbove is the setup method for a FlySky 9 channel transmitter wi th FrSky D4R-II receiver which uses the “No Signal” method. Similar to the “Low-Throttle” method, with the LiPo battery dis connected: Connect your flight controller to the mission planner and selec t Initial Setup >> Mandatory Hardware >> Failsafe. Set the Failsafe Options to one of the three options: “Enabled always RTL” to force the vehicle to always RTL even if flying a mission in AUTO mode “Enabled Continue with Mission in AUTO” to allow the vehicle to continue with missions even if it takes the vehicle outside of RC range (not recommended).  In all other cases the vehicle will RTL. “Enable always LAND” to force the vehicle to Land immediately i f it loses RC contact Because the throttle is not pulled low, there is normally no ne ed to adjust the “FS Pwm” value from it’s default (975).  Just ensure that it’s well below (i.e . at least 10pwm points below) the minimum value that channel 3 (throttle) can be. 

## Testing You can check your failsafe by performing the following tests w ith the Pixhawk/APM connected to the 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 b attery you should first remove the propellers. Test #1 : if using the “Low-Throttle” method, ensure the thrott le channel drops with loss of radio contact 1. Ensure 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 definitely be at lea st 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) belowTest #2 : ensuring motors disarm if in stabilize or acro with t hrottle at zero Switch to stabilize mode, arm your motors but keep your throttl e at zero. Turn off your transmitter. The motors should disarm immediately (red led will start flashing, DISARMED will be displayed in the Mission Planner’s Flight Data screen).Test #3 : ensuring flight mode changes to RTL or LAND when thro ttle is above zero Switch to stabilize mode, arm your motors and raise your thrott le to the mid point. Turn off your transmitter. The Flight Mode should switch to RTL if you h ave 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 the failsafe has cleared continuing on from test #3, turn your 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 throttl e 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 Te st #3 Warning: unplug the APM so that it is powered down before reatt aching the receiver’s power 

## Using the receiver to set the flight mode (not recommended) Instead of setting up the receiver and flight controller as des cribed above (i.e. “Low-Throttle” and “No Signal” methods) the receiver can be set-up to set chan nel 5 (flight mode channel) to a flight mode slot that has been set to RTL.  For example the receiver could be setup to move ch5’s pwm value to 1700 which is “Flight Mode 5” which could th en be set to RTL on the Mission Planner’s Initial Setup >> Mandatory Hardware >> Flight Modes screen. Although this mostly works it is not recommended because it wil l not trigger if the receiver loses power or if the wires between the receiver and flight controlle r are broken. 

## Warning to Copter 3.1.5 and 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 theflight mode channel (channel 5) when a failsafe event occurs. For these receivers if using Copter 3.1.5 (or earlier) it is important to setup the receiver ’s channel 5 failsafe value so that the Pixhawk/APM is switched into RTL, Loiter or LAND.  This is critical because there is a very short period of time (3/50ths of a second) between when the rec eiver pulls the throttle low and when the Pixhawk/APM initiates the RTL or LAND.  During this ti me, if the receiver also switches the flight mode channel to stabilize or acro the Pixha wk/APM may switch to stabilize momentarily and then because the copter is in stabilize with th rottle at zero it will disarm the copter (i.e. Test #2).
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Contents [ hide ] 1 Overview 2 Enabling the Fence in Mission Planner 3 Enabling the fence with Channel 7 or 8 4 Warnings: 5 Video overview of the Fence setup and Operation 

## Overview AC 3.0.1 (and higher) includes a simple “tin can” shaped fence centered on home that will attempt to stop your copter from flying too far away by initiat ing an RTL.  The maximum circular distance and altitude and the vehicle behaviour when the fence is reached can be configured using Mission Planner. ArduPilot > Copter > Simple GeoFence 

# Simple GeoFence Copter

EnglishIf 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 corr ectly or the operator takes control but is unable to bring the copter back towards home) th e copter will be switched into RTL again (and another backup fence an additional 20m further o ut will be created). If the copter eventually flies 100m outside the configured fenc e 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 cour se 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. 

## Enabling the Fence in Mission PlannerThe 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 “Circ le”) 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 Planner’s Software > Copter Pids screen and s et either “Ch7 Opt” OR “Ch8 Opt” to Fence. holding the switch high (i.e. PWM > 1800) will enable the fence , low (under 1800) will disable the fence.

## Warnings: The minimum recommended fence radius is 30m The fence requires the GPS to be functioning well so do not dis able the GPS arming check nor the GPS failsafe while the fence is enabled.  Conversely if you disable either of these checks, disable the Fence. For the best results, ensure RTL is working on your vehicle. With the Fence enabled, the pre-arm checks will require you hav e GPS lock before arming the vehicle. If GPS failsafe is not enabled and the Fence is enabled and you loose GPS lock while flying the fence will be disabled. If GPS failsafe is enabled and the Fence is enabled and you los e GPS lock while flying the vehicle will switch to LAND because we no longer know the vehic le position and we want to ensure the copter never travels far outside the fence.  This be ahviour 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 breache d fence not 20m out from the vehicle’s position.  This means if you choose to override t he fence you may have less than 20m to regain vehicle control before the fence switches th e 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. 

## Video overview of the Fence setup and Operation

### ArduCopter 3.0 Fence

Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Mission Planner

is free, open source software available for Windows. These ins tructions will guide you through installing Mission Planner on your ground station computer.
Contents [ hide ] 1 Download the most recent Mission Planner installer file 2 Run the installation utility 3 Open Mission Planner 4 Updating Mission Planner 

# Download the most recent Mission Planner installer file Go to the Mission Planner download page and click on the Download button to get the most recent Misson Planner installation file.



# Run the installation utility ArduPilot > Copter > common-Installing Mission Planner 

# Installing Mission Planner Copter

EnglishOpen the Microsoft installer file (.msi) and select Run to run the installation utility.

Follow the instructions to complete the setup process. The inst allation utility will automatically install any necessary software drivers. If you receive a Direct X installation error, please update your DirectX plug-in from the DirectX Download Center

. If you receive the warning pictured here, select Install this driver software anyway to continue.Mission Planner

is normally installed in the C:\Program Files (x86)\APM Planner folder or the C:\Program Files\APM Planner folder. That is where your log files folder is located. An icon to open the Mission Planner is created according to your instructions during the installation. 

# Open Mission Planner Once installation is complete, open Mission Planner by clicking on its system icon. Then you can either: Connect Mission Planner to AutoPilot in order to receive telemetry and control the vehicle, or Load Firmware 

# Updating Mission Planner Mission Planner

automatically notifies you about available updates (when it is connected to the Internet). Please always run the most current version of Mission Planner.
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Note: On the Mission Planner

‘s Initial Setup screen select Mandatory Hardware | Frame Type

. Select the frame for your copter. The default configuration is X . If you want one of the arms to serve as the exclusive front-facing direction, select the Plus configuration. For Tricopters, Traditional Helis and Y6s, the frame type is ignored.

Mission Planner: Select Frame Type For an H-Frame quadcopter use the option to set the frame type to ‘3’ in the ArduPilot > Copter > Frame Type Configuration in Mission Planner 

# Frame Type Configuration in Mission Planner Copter

EnglishAdvanced Parameter Tab. To apply the H-frame configuration, swap the left rear an d right rear props and reverse the motor direction for each of those mo tors (by swapping any two motor wires). Repeat the same process for the front two motors.
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Copter: This article shows how you can enable up to 6 autopilot control /flight modes to be set from your RC transmitter.

Contents [ hide ] 1 Flight modes configuration 2 Setting the flight mode channel 3 Transmitter configuration 3.1 Test transmitter switch settings 3.2 Tutorials for specific RC hardware 3.3 Spektrum DX8 (alternate method) 

# Flight modes configuration The mapping between switch position and flight mode is set in t he Mission Planner Flight Mode screen. ArduPilot > Copter > common-RC Transmitter Flight Mode Configuration 

# RC Transmitter Flight Mode Configuration Copter

EnglishNote: Mission Planner: Flight Mode Screen (Copter).

You can set up the flight modes available on the transmitter by doing the following: Turn on your RC transmitter Connect the Pixhawk (or other flight controller) to the Mission Planner Go to the Initial Setup | Mandatory Hardware | Flight Modes screen As you move your transmitter’s flight mode switch the green hig hlight bar will move to a different position. Use the drop-down on each line to select the flight mode for th at switch position. (Copter) Ensure that at least one switch position is left assig ned to STABILISE.
(Copter) Optionally check the Simple Mode check-box for that switch position. If using AC3.1 or higher you can optionally set Super Simple mode . If both Simple mode and Super Simple mode checkboxes are checked Super Simple will be u sed. When finished press the Save Modes button. Some modes can also be invoked from the auxiliary switches (a.k.a. ch7, ch8 option switches). For example, to set a dedicated switch for RTL.Note: 

# Setting the flight mode channel The flight mode channel is the input radio channel that ArduPil ot monitors for mode changes. On Copter this is always channel 5. 

# Transmitter configuration The transmitter must emit PWM signals in the correct range to a llow us to map a mode to a switch position. The correct PWM ranges for selectable modes are shown alongside each mode selection dropdown in the Mission Planner Flight Mode screen (see screenshot above ). If you want to just support three modes (using a three position switch) then you would configure the transmitter to produce PWM pulse widths of 1165, 1425, and 1815 microseconds for the respective switch positions. If you want to support 6 modes then the transmitter will need t o emit PWM widths of around 1165, 1295, 1425, 1555, 1685, and 1815 milliseconds. Typically this is achieved by configuring the transmitter to mix a two position switch and a three positi on switch (giving 6 modes in total). You can also do this with an analog dial if one is available, b ut it’s hard to reliably turn a dial to just the right position for six distinct settings. The sections below provide links showing how to configure trans mitters from different manufactures, and how to test (in Mission Planner) that each sw itch setting is emitting the appropriate PWM signal. 

## Test transmitter switch settings You can use the Mission Planner Radio Calibration screen to test the PWM pulse widths for each mode setting. Simply toggle through the modes on your transmitter and confirm that the PWM for the selected channel matches the required PWM values. The screenshot below a ssumes that the flight mode channel is set to Radio 5.

## Tutorials for specific RC hardware Here are some user-contributed tutorials for doing this (or add ing more modes to RC units with just a two-position toggle) with various RC systems: JR XG8 DMSS JR9303 JR X2720 Futaba T8FG Futaba T8J Futaba T7CP Futaba T6EX Futaba 12fg Futaba 9ZAP/ZHP Futaba T10CAG Futaba T14 Futaba 9C Super Graupner MX-16 Turnigy 9x (or an even easier way) (Here!) Turnigy 9x with ER9x firmware Turnigy 9XRHitech Aurora 9 Spektrum DX8 (alternate method below) Spektrum DX7 Spektrum DX7s Spektrum DX7 Version 6 Or build your own six-position switch! 

## Spektrum DX8 (alternate method) This section describes an alternative way to set 6 modes with t he Spektrum DX8. This method uses the Gear switch and the Flight mode switch. All the other switches can be assigned as preferred. This method also allows each mode to be set in the m iddle of each mode’s pulse width range so small changes will not change modes. Use Mission Planner Flight Modes setup to monitor the Current PWM for these adjustments. 1. Setup the switches (*required for the 6 modes) Hold roller bar down, turn on DX8, scroll down to Switch Select , Click roller bar.  Set switches as follows: * Gear = Gear (Channel 5) * FMode = Inh  Not assigned to a channel – Used to mix with Gea r Sw (Channel 5) for 6 modes Others anyway you want. One method is as follows: Knob to aux1 = channel 6 for camera tilt / tuning Mix = aux2 = channel 7 to save Way Point or RTL, auto trim or o ther settings in APM configuration. Flap to aux3 = channel 8 for other uses Click BACK until the normal screen appears, or turn off power, then turn power back on. 2. Set up the non-mixed servo setting for channel 5 (Gear channel controlled by the Gear Switch) This will be the values with no mixing – F Mode switch in the 0 position and sets the lowest pulse width to 1165 ms (mode 1) and highest to 1815 ms (mode 6) Click the roller bar, scroll down to Servo Setup, Select the Ge ar channel, Select Sub Trim. Set sub trim to 0 Select Travel. Set travel (left, position 0) for 1165 ms pulse  (~90%). Set travel (right, position 1 for 1815 ms pulse (~74%).3. Set up Mix 1 to change the Gear Pulse width when F Mode is in position 1

Click roller, scroll down to Mixing, click roller, scroll to fi rst line under Mix (has xxx > xxx, AIL > RUD, or some other mix set),click roller, Select Mix 1, C lick roller. Set Mix: Gear > Gear. Gear changes Gear depending on Switch F M ode setting Set Offset = 0, Trim = Inh. Set SW = FM 1 Set the F Mode switch on the transmitter to position 1. Set the Gear switch on the transmitter to position 0. Set top Rate for pulse width of 1290 ms for mode 2  (~-35%) (change = 400 ms * -90% * -35% = 126 ms. Result = 1165 ms + 126 ms = 1251 ms = mode 2) Set the Gear switch on the transmitter to position 1. Set bottom Rate for pulse width of 1685 ms for mode 5  (~– 45%) (change = 400 ms * +73% *- 45% = -131 ms. Result = 1815 ms – 13 1 ms = 1684 ms = mode 5) 4. Set up a mix 2 to change the Gear Pulse width when F Mode is in position 2 Mix: Gear > Gear.  Gear changes Gear depending on Switch F Mode setting. Set Offset = 0, Trim = Inh Set SW = FM2 Set the F Mode switch on the transmitter to position 2 Set the Gear switch on the transmitter to position 0. Rate top Rate for pulse width of 1425 ms for mode 3  (~–72%) (c hange = 400 ms * –90% * – 72% = 259 ms.  Result = 1165 ms + 259 ms = 1424 ms = mode 3 ) Set the Gear switch on the transmitter to position 1. Set bottom Rate for pulse width of 1550 ms for mode 4  (~–89%) (change = 400 ms * +73% * – 89% = -262 ms.  Result = 1815 ms – 262 ms = 1553 ms = mode 4)
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.This article explains how to connect the ESCs, Motors and Prope llers for Pixhawk, PX4, and APM 2.x.
Contents [ hide ] 1 Connect motor PWM signal outputs (Pixhawk/PX4) 2 Connect motor PWM signal outputs (APM2) 3 Motor order diagrams 3.1 Quad 3.2 Hexa, Octo, Y6 3.3 X8 3.4 Tricopter 4 Attach propellers 4.1 Recognizing clockwise and counterclockwise propellers 5 Choosing propellers 6 Testing motor spin directions 7 Checking the motor numbering with the Mission Planner Motor t est 8 KDE (and other) Opto Isolated ESCs 9 Pixhawk ESC issues 

# Connect motor PWM signal outputs (Pixhawk/PX4) Connect the power (+), ground (-), and signal (s) wires for eac h ESC to the controller main output pins by motor number. Find your frame type below to dete rmine the assigned order of the motors. ArduPilot > Copter > Connect ESCs and Motors 

# Connect ESCs and Motors Copter

EnglishWarning:

Note: Pixhawk Output pins (numbered). First 4 pins are colour-coded f or connecting a Quad frame The APM PDB described in the following section is not compatibl e with the Pixhawk or PX4. 

# Connect motor PWM signal outputs (APM2) There are two methods of connecting the motor outputs: connect the electronic speed controllers (ESCs) to autopilot controller board directly or us e a power distribution board (PDB). When using a PDB, connect the power (+), ground (-), and signal (s) wires for each ESC to the PDB according to motor number. Find your frame type below to de termine the assigned order of the motors. Then connect the signal wires from the PDB to th e main output signal pins on the flight controller board (ensuring that the motor order numbers match the main output pin numbers on the controller). If you are using a power module, it is optional to connect the power and ground wires from the PDB to the flight controller board. I f you would like to use these cables in addition to or instead of the power module or as a co mmon point for low current servos, connect the ground (-) wire to a main output ground (-) pin and the power (+) wire to a main output power (+) pin. Information on assembling PDB is found here for Quad and here for Hexa

.When connecting the ESCs directly to autopilot board, connect t he power (+), ground (-), and signal (s) wires for each ESC to the controller main output pin s by motor number. Find your frame type below to determine the assigned order of the motors.

APM Output Pins (numbered) 

# Motor order diagrams The sections below show motor order for each frame type (the nu mbers indicates the connected autopilot output pin) and the propeller direction (cl ockwise (CW) motors are shown in green and take pusher propellers,counterclockwise motors (CC W) are shown in blue and take puller propellers. Use the diagram for your frame type, and wire the motors as sho wn.Legend for motor-order diagrams 

## Quad

Hexa, Octo, Y6Note: 2014 3DR RTF Y6 uses the Y6B configuration. 

## X8

TricopterNote: If the direction of your tail servo is going the wrong way in r esponse to yaw then either the RC7_REV or MOT_YAW_SV_REV parameter should be set to -1 (from 1), See TriCopter setup page for details.) 

# Attach propellers Find your frame in the motor order diagrams above. Clockwise mo tors are shown in green, marked CW, and take pusher propellers. Counterclockwise motors are shown in blue, marked CCW, and take puller propellers. Use the diagram for your frame type, and attach propellers to your vehicle as shown. For copters, attach propellers with the writing facing towards the sky. For more information on recognizing the different types of prop ellers, see the next section.



## Recognizing clockwise and counterclockwise propellersNote: 

## Recognizing clockwise and counterclockwise propellers The diagrams above show two types of propellers: clockwise (cal led pushers) and counterclockwise (called pullers). Pusher propellers are often marked with a P. However not all propellers are marked and both types are often available in eit her rotational direction. Therefore, it is most reliable to recognize the correct propell er type by its shape as shown below. Note that the propellers below have the edge with the sh allow consistent curve at the leading edge in direction of rotation and the more radical scal loped (and usually thinner edge) as the trailing edge. You can use these features to recognize p ropellers of the correct direction

of rotation.



# Choosing propellers Propellers come in many varieties and are suited to different n eeds. Have experience choosing propellers? Help us by editing this se ction! 

# Testing motor spin directions If you have completed the Radio and ESC calibration , you can check that your motors are spinning in the correction direction: 1. Make sure there are no propellers on your copter! 2. Turn transmitter on and ensure the flight mode switch is set to Stabilize.Tip: 3. Connect battery. 4. Arm copter by holding the throttle down and rudder right for five seconds. 5. If it fails to Arm with the throttle down and to the right and the motors will not spin, it has probably failed the  Pre-Arm Safety Check. Pre-Arm safety check failure is also indicated by the red armin g light double flashing and then repeating. If the Pre-Arm check fails go to the Prearm Safety Check Page and correct the problem or disable the check before continuing. 6. When you can Arm successfully, apply a small amount of throttle, and observe and note spin direction of each motor. They should match directions shown in the images above for the frame you’ve chosen. 7. Reverse any motor spinning in the wrong direction. Motor Direction is reversed simply by interchanging two of the three ESC to motor power leads. 

# Checking the motor numbering with the Mission Planner Motor test An alternative way to check that the motors have been hooked up correctly is to use the “Motors” test in the Mission Planner Initial Setup menu.

When connected to the vehicle via MAVLink, you can click on the green buttons shown above and the corresponding motor should spin for five seconds. Lette rs correspond to motornumbers as shown in the example below. Take off your props first! If no motors turn, raise the “Throttle %” to 10% and try again. If that doesn’t work, try 15% The first motor to spin will be the one located directly forwar d 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-right, and proceed around with the same pattern. OctoV will spin the front-right motor first, and then again, pr oceed clock-wise until reaching the front left motor. 

# KDE (and other) Opto Isolated ESCs The KDEXF-UAS and KDEF-UASHV Series are opto-solated and do not provide BEC power output for the peripheral equipment. They require +5V to power the opto-isolator and while the Pixhawk can be powered from the servo rail, it does not provide +5V to the servo rail. TheESCs must be powered by a BEC or with a jumper from an unused c onnector on the board. It is strongly recommended that you use a BEC to power the rail ra ther than a jumper. Do not add servos or other devices to the servo rail as the power module i s not intended to supply power to them.

The KDE ESCs have fixed PWM ranges so you must manually set the output range of each PWM signal so that RCx_MIN is 1100 and RCx_MAX is 1900us using the Advanced Parame ter or Full Parameter Settings Page in the planner. 

# Pixhawk ESC issues Some ESCs have been reported as not working with Pixhawk. The Pixhawk should work with every ESC that works with a normal RC receiver (because it sends the same type of signal) but there is one known exception, the EMAX ESC

. In most cases problems are due to incorrect wiring. Always conn ect signal and ground. Check your ESC type to decide how to connect the +5V line. On APM2.x you could get away with using the power ground as the signal return with the APM but fo r Pixhawk you must connect both the signal and the signal ground in order to make the ESC work. For more information see this page and the video here

. Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Note: Electronic speed controllers are responsible for spinning the m otors at the speed requested by the autopilot. Most ESCs need to be calibrated so that they kno w the minimum and maximum pwm values that the flight controller will send.  This page pro vides instructions for calibrating ESCs. Please complete radio calibration before performing ESC calibration.

Contents [ hide ] 1 About ESC Calibration 2 All at once calibration 3 Manual ESC-by-ESC Calibration 3.1 Calibrating ESCs individually (Currently Untested on PX4) 4 Testing 5 Notes / Troubleshooting 

# About ESC Calibration ESC calibration will vary based on what brand of ESC you are us ing, so always refer to the documentation for the brand of ESC you are using for specific i nformation (such as tones).  “All at once” calibration works well for most ESCs, so it is good id ea to attempt it first and if that fails try the “Manual ESC-by-ESC” method. For 3DR ESCs can use the “All at once” method. ArduPilot > Copter > Electronic Speed Controller (ESC) Calibration 

# Electronic Speed Controller (ESC) Calibration Copter

EnglishWarning: DJI Opto ESCs do not require and do not support calibration, so skip this page completely Some brands of ESC do not allow calibration and will not arm un less you adjust your radio’s throttle end-points so that the minimum throttle is around 1000 PWM.  Note that if you change the end-points on your TX you must re-do the Radio Calibration

. Begin this procedure only after you have completed the radio control calibration and Connect ESCs and motors part of the Assembly Instructions .  Next follow these steps: 

# All at once calibration

Safety Check! Before calibrating ESCs, please ensure that your copter has NO PROPS on it and that the APM is NOT CONNECTED to your computer via USB and the Lipo batt ery is disconnected.

1. Turn on your transmitter and put the throttle stick at maximum.

2. Connect the Lipo battery.  The autopilot’s red, blue and yellow LEDs will light up in a cyclical pattern. This means the it’s ready to go into ESC calibration m ode the next time you plug it in.3. With the transmitter throttle stick still high, disconnect and reconnect the battery.

4. For PX4 or Pixhawk, press and hold the safety button until it displays solid red. 5. The autopilot is now in ESC calibration mode. (On an APM you may notice the red and blue LEDs blinking alternatively on and off like a police car). 6. Wait for your ESCs to emit the musical tone, the regular number of beeps indicating your battery’s cell count (i.e. 3 for 3S, 4 for 4S) and then an addi tional two beeps to indicate that the maximum throttle has been captured. 7. Pull the transmitter’s throttle stick down to its minimum position.

8. The ESCs should then emit a long tone indicating that the minimum throttle has been captured and the calibration is complete. 9. If the long tone indicating successful calibration was heard, the ESCs are “live” now and if you raise the throttle a bit they should spin. Test that the mo tors spin by raising the throttle a bit and then lowering it again. 10. Set the throttle to minimum and disconnect the battery to exit ESC-calibration mode. Here is a video demonstrating the process:

### ESC Calibration "All-at-once" method

Demonstration of ESC calibration process with Pixhawk:Warning: 

### 3D Robotics IRIS - Calibrate the ESC



# Manual ESC-by-ESC Calibration

Safety Check! Before calibrating ESCs, please ensure that your copter has NO PROPS on it and that the APM is NOT CONNECTED to your computer via USB.



# Calibrating ESCs individually (Currently Untested on PX4) 1. Plug one of your ESC three-wire cables into the throttle channel of the RC receiver. (This is usually channel 3.) 2. Turn on the transmitter and set throttle stick to maximum (full up). 3. Connect the LiPo battery 4. You will hear a musical tone then two beeps.5. After the two beeps, lower the throttle stick to full down. 6. You will then hear a number of beeps (one for each battery cell you’re using) and finally a single long beep indicating the end points have been set and th e ESC is calibrated. 7. Disconnect battery. Repeat these steps for all ESCs. 8. If it appears that the ESC’s did not calibrate then the throttle channel on the transmitter might need to be reversed. 9. If you are still having trouble after trying these methods (for example, ESCs still beep continuously) try lowering your throttle trim 50%. 10. You can also try powering your APM board via the USB first to boot it up before plugging in the LiPo. 

# Testing Once you have calibrated your ESCs, you can test them by pluggi ng in your LiPo.  Remember: no propellers! Ensure your transmitter’s flight mode switch is set to “Stabili ze Mode”. Arm your copter Give a small amount of throttle.  All motors should spin at abo ut same speed and they should start at the same time. If the motors do not all start a t the same time and spin at the same speed, the ESC’s are still not properly calibrated. Disarm your copter 

# Notes / Troubleshooting The All-at-once ESC calibration mode simply causes the APM to p ass through the pilot’s throttle directly through to the ESCs. If you power up the APM while in this mode you’ll send the same PWM signal to all the ESCs. That’s all it does.  Many ESCs use full throttle at startup to enter programming mode, full throttle postition is then saved a s the upper end point and when you pull the throttle down to zero, that position is saved as t he lower end point. If after calibration your motors do NOT spin same speed nor sta rt at the same time, repeat the calibration process. If you tried the auto calibration above an d it didn’t work or the ESCs do not drive the motors identically, try the manual calibration method described above. That should work almost every time. (Rarely after a full manual calibration you will also need to do an additional final automatic calibration).Finally, there are a huge number of brands and types of ESCs av ailable and some of them do not adhere to the normal programming conventions (sometimes eve n though they claim to) and they may simply not work with the APM the way it is now. This i s an unfortunately necessary but true disclaimer. Recommended ESC settings as follows: 1. Brake: OFF 2. Battery Type: Ni-xx(NiMH or NiCd)  (even if you’re using Li-po batteries this setting reduces the likelihood that the ESC’s low voltage detection will turn o ff the motors) 3. CutOff Mode: Soft-Cut (Default) 4. CutOff Threshold: Low 5. Start Mode: Normal (Default) 6. Timing: MEDIUM
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.This topic covers basic Roll and pitch and throttle tuning.

Contents [ hide ] 1 Overview 2 Roll and pitch tuning 3 Throttle tuning 

# Overview After your first flight, you may notice that you copter doesn’t respond to control inputs the way you want it to or you may have trouble maintaining control of y our copter. If you are familiar with PID controllers, check out the advanced tuning guide here . If you are an experienced operator, try out the autotune feature . This page will cover the basic tuning section of Mission Plan ner and APM Planner that simplified the complex tuning process into a few simple sliders. This is the best tuning method for new operators. 

# Roll and pitch tuning Tuning is easiest at the field using a telemetry radio . Perform an initial flight with the following questions in mind: How does the copter respond to roll and pitch? Is the response more sluggish or twitchy than you want? When the copter is hover, what level is the throttle set at? Do es it hover at the middle position of the stick or is it above or below the center positi on? ArduPilot > Copter > Basic Tuning 

# Basic Tuning Copter

EnglishWhen raising the throttle, what rate does the copter accelerate at? Does it gain altitude more slowly or more quickly than you want? Connect the telemetry radio ground module to your ground statio n computer and open either Mission Planner or APM Planner. Select the correct COM port and select Connect. You should see live data on the Flight Data screen. To begin tuning, selec t Config/Tuning and Basic Tuning. Start with the Roll/Pitch slider at the top of the page. If you observed that your copter was too twitchy in response to roll and pitch controls, move the slider one tick mark to the left, or, if you observed that your copter was too sluggish, move the slider one tick mark to the right. Repeat your flight to determine if the change was beneficial. Repeat t he process until you are satisfied with the way your copter responds to roll and pitch.

# Throttle tuning The bottom two sliders allows you to tune the throttle control. Adjust the slider marked Throttle Hover until the copter hovers at the throttle stick’s middle po sition. If the copter hovers with the throttle stick above middle position, move the slider to the le ft by one tick-mark until it hovers at mid-stick, testing as you go. If the copter hovers with the thr ottle stick below middle position, move the slider to the right by single tick-mark increments unt il it does. Make sure to test each set of tuning settings as you go. Move the slider marked Throttle Accel or Climb Sensitivity to t he right to have the copter gain altitude more aggressively or to the left to have the copter ga in altitude more gently. Test each increment after setting to evaluate the tune.
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.If you have a slightly overpowered or underpowered copter the t hrottle required to keep the vehicle in a stable hover may be under 40% or over 60%.  Althou gh this is fine while flying purely stabilize mode it can lead to a rough transition to auto pilot modes (Alt Hold, Loiter) where having the throttle outside of the 40% ~ 60% deadzone wil l be interpreted as meaning you want the copter to climb or descend. For this reason it is a good idea to adjust the Throttle Mid pa rameter (also known as THR_MID) so that your mid throttle while in stabilize mode is closer to 50%. Please follow these instructions to adjust your manual throttle to so that your copter hovers at 50% throttle: Fly your copter in stabilize mode in a stable hover for at leas t 30 seconds Disconnect your lipo battery and connect your APM/PX4 to the Mi ssion Planner Go to the Terminal screen and download your latest dataflash lo g file (more details on working with dataflash logs can be found here ) ArduPilot > Copter > Setting Throttle Mid 

# Setting Throttle Mid Copter

EnglishAfter the download has completed, close the “Log” window and pu sh the “Log Browse” button and open the latest file in the log directory (it’s last digit will be the Log number you downloaded so in the example above we downloaded Log #1 so the filename will end in 1.log)When the Log Browser appears, scroll down until you find any CT UN message.  Click on the row’s “ThrOut” column and push “Graph this data Left” button.

While referring to the scale on the left of the graph, estimate approximately what the throttle level was during the hover.  In the example above (which was an unnecessarily long flight) the mid throttle appears to be about 550.

Note: if the average throttle is below 300 (i.e. 30%) then you have a veryoverpowered copter and it would be best to add a some extra wei ght (i.e. a

bigger battery perhaps) or reduce the power in some other way ( smaller motors, move from a 4S to a 3S battery, etc) If the average throttle is above 700 (i.e. 70%) then you have a very underpowered copter.  You should consider increasing the power of the motors and ESCs or use a higher voltage battery (i.e. switch from a 3S to a 4S battery). Open the Mission Planner’s Software > Standard Params screen an d update the Throttle Mid Position (THR_MID) to the value estimated above (you’ll fin d it near the bottom of the list) Push the Write Params button

On your next flight you should find the throttle is closer to m id while flying in stabilize mode
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.This page covers the installation of the 3DR UBlox GPS + Compass module

.

Contents [ hide ] 1 Overview 2 Connecting the Autopilot 2.1 Connecting to Pixhawk 2.2 Connecting to APM 2.x 2.3 Connecting to PX4 3 Mounting the GPS Module 4 Setup in Mission Planner 5 LED Indicators 6 Advanced Configuration 

# Overview The 3DR UBlox GPS + Compass module is the recommended GPS for Pixhawk, PX4 and APM2.6 (and above) flight controllers using Plane, Rover and Co pter.  These come set-up with the best known GPS configuration and have been thoroughly tested by thousands of users. ArduPilot > Copter > common-3DR UBlox GPS + Compass Module 

# 3DR UBlox GPS + Compass Module Copter

English

# Connecting the Autopilot Connecting to Pixhawk Connect the GPS’s 6-pin DF13 connector to the Pixhawk’s “GPS” p ort and the compass’s 4-pin connector to the I2C port.  Alternatively the compass can be fi rst connected through an I2C splitter if other I2C devices are to be attached.As of Copter 3.2 and recent versions of Plane and Rover, a seco ndary GPS can be connected to the Pixhawk’s Serial 4/5 port.  Limited testing suggests tha t a secondary GPS can reduce the likelihood that GPS glitches will affect the vehicle but can al so lead to sudden movements of the vehicle when the primary GPS switches. If the parameters are set-up as shown below, the flight control ler will use the GPS with the higher number of satellites (Note: it will switch when one GPS has at least 2 more satellites than the other). GPS_AUTO_SWITCH = 1 GPS_TYPE2 = 1 And if using Copter 3.3 or higher or recent versions of Plane/R over then these parametersshould also be set: SERIAL4_PROTOCOL = 5 SERIAL4_BAUD = 38

Note that a secondary external compass cannot be attached. 

## Connecting to APM 2.x APM 2.6 is compatible with the 3DR UBlox GPS + Compass module

. To connect the GPS module to APM 2.6, attach the GPS port to th e APM GPS port using the included 5-position-to-6-position cable (use the top-entry port , not the side-entry port), and attach the GPS MAG port to the APM I C port using the included 4-position cable. 2Note: APM 2.5 and APM 2.0 have an internal compass (unlike APM 2.6) w hich must be disabled by cutting a trace before you can connect the 3DR UBlox GPS + Compass module (the video here shows how). Other than disabling the internal compass, connecting the UBlox is the same for APM2.0/APM2.5 as for APM2.6. After connecting the external compass you will need to re-calib rate the compass including Compassmot (if you had run this procedure for the internal compass). 

# Connecting to PX4 To connect GPS part of the this module to PX4, connect the GPS port to the PX4FMU’s GPS connector. Connect the compass lead on the module to the PX4IO’s I2C port. The PX4IO board I2C port is the 4 pin connector located on the board side opposite the Servo Out connectors in the second row of connectors in and nex t to the board mounting hole.When the external compass is plugged into the PX4IO boards I2C port, it is automatically detected and used and the internal compass is disabled.

Next connect with the Mission Planner and go to INITIAL SETUP | Mandatory Hardware | Compass and set the Orientation to ROTATION_ROLL_180
. 

# Mounting the GPS Module This module permits the GPS to be mounted separately from the f light control module so that it can have the best clear (view) of the sky and allows the compas s to be distanced from interfering magnetic fields. When mounting the GPS+Compass modu le: Place the module on the outside of your vehicle (in an elevated position if appropriate) with a clear view of the sky, as far as possible from the motors and E SCs, with the arrow facing forward. Distance the module from DC power wiring and the batteries by a t least 10cm.  Use of a mast is highly recommended. Place the module clear of nearby iron containing metallic objec ts. (Use nylon or non magnetic stainless steel hardware and nylon or aluminum standof fs to mount the module). Twist power and ground wires where possible.

# Setup in Mission Planner Start Mission Planner, connect your autopilot, and select the “ Connect” tab. Select the “Initial Setup” tab, then select the left menu “Mandatory Hardware” tab and select the “Compass” tab. Select the option to Enable the compass and to allow Auto Dec. To manually input the declination, select Declination Website and enter the magnetic declination minutes and seconds for your location. Next select your autopilot configuration, for Pixhawk and PX4, select the option Pixhawk/PX4 with the image of the Pixhawk. For APM 2.6, select APM with Ext ernal Compass with the image of the GPS with Compass module. These options will automaticall y enter the correct orientation for the board. Ensure that you have mounted the GPS with Compas s with the arrow facing toward the front of the vehicle and in the same direction as th e arrow on the autopilot.

To input a manual orientation for APM, select the Manual option at the bottom of the screen, and consider the following factors when selecting an orientatio n. Note: The information below does not apply to Pixhawk and PX4; for these autopilots, select the Pixhawk/PX4 option toassign the correct orientation. If the GPS / compass board is mounted in its correct direction (arrow pointing forward) and the Flight controller board is also mounted right side up with its arrow pointing forward, the (COMPASS_ORIENT) parameter will need to be set to (Roll 180) or “8” because the compass is upside down under the GPS modules antenna. If the Flight controller board is put in an alternate orientati on, the Orientation (i.e. COMPASS_ORIENT parameter) should be set according to the gps’s attitude to the flight controller.  So for example if both the Flight controller and t he GPS+compass module were mounted on the bottom of the vehicle (a ridiculous example) the n you would leave the Compass orientation as ROTATION_ROLL_180.  If however you wante d to mount the GPS+Compass right-side-up you would pick Orientation “ROTATION_ NONE” because the original rotation was Roll 180, then you add the compass rotati on which is another roll 180 = Roll 360 = no rotation. 

# LED Indicators The 3DR GPS+Compass module has two LED indicators: one for powe r (solid red) and one for GPS lock (flashing blue).

LEDs: Behavior: Power Solid red when powered GPS lock Flashing blue when 3D GPS lock acquired 

# Advanced Configuration Advanced configuration of the UBlox GPS’s internal settings is documented in UBlox GPS Configuration

. Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.Note: This article shows how to perform basic accelerometer calibrati on (using Mission Planner ). Accelerometer calibration is mandatory if you’re using EKF to estimate vehicle position

.
Contents [ hide ] 1 Calibration steps 2 Video demonstration (Copter) 

# Calibration steps 1. Under Initial Setup | Mandatory Hardware , select Accel Calibration from the left-side menu. ArduPilot > Copter > common-Accelerometer Calibration in Mission Planner 

# Accelerometer Calibration in Mission Planner Copter

EnglishTip:

Mission Planner: Calibrate Acceleration 2. Click Calibrate Accel to start the calibration. Mission Planner

will prompt you to place the vehicle each calibration position . Press any key to indicate that the autopilot is in position and then proceed to the next orientation. The calibration positions are: level, on right side, left side, nose down, nose up and on its back.

Accelerometer Calibration Positions (Copter)
It is important that the vehicle is kept still immediately afte r pressing the key for each step. You may need to calibrate the board before it is mounted if the size/shape of the vehicle makes this difficult. The level position is the most important to get right as this w ill be the attitude that yourcontroller considers level while flying.
3. Proceed through the required positions (it is not necessary to use the Click When Done button).

Mission Planner: Accel Calibration – press any key 4. When you’ve completed the calibration process, Mission Planner will display “Calibration Successful!” as shown below.

Mission Planner: Calibration SuccessfulWarning: Do not perform the press the Calibrate Level button. This function will overwrite your calibration values. 

# Video demonstration (Copter) Video demonstration of accelerometer calibration. This is for a n older version of Copter/Mission Planner, but is useful as an example of how you might hold a Copter. 

### Ar duCopter 2.9 Accel Calibration from Randy Mackay

02:34

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.Note: This article explains how to measure vibration levels and confi rm they are acceptable.
Contents [ hide ] 1 Overview 2 Copter-3.3 and later versions 3 Earlier firmware versions 

# Overview Flight controller accelerometers are sensitive to vibration. As accelerometer data is used to estimate vehicle position (along with barometer and GPS reading s), excessive vibration can lead to poor performance in modes that rely on accurate positio n calculation. Vibration affects all vehicle types, but is most critical for the Copter (particu larly in AltHold, Loiter, RTL, Guided, Position and AUTO flight modes). These instructions explain how to measure the vibration levels. If you find they are out-oftolerance then follow the advice found on the First Time Set-up sections Vibration Damping

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# Copter-3.3 and later versions At time of writing (27 July 2015), Copter-3.3 is still a releas e candidate. Its changes are not yet present the official release of Copter, Plane and R over. The changes here are expected to be in the next release of Plane and Rover. ArduPilot > Copter > common-Measuring Vibration 

# Measuring Vibration Copter

EnglishPerform a regular flight (i.e. not just a gentle hover) of at l east a few minutes and download the dataflash logs

. Using the Mission Planner or other GCS graph the VIBE message’s VibeX, VibeY and VibeZ values.  These show the standard deviation of the primary accel erometer’s output in m/s/s. The image below, taken from a 3DR IRIS, shows normal levels whi ch are below 15m/s/s but occasionally peak to 30m/s/s.  Maximum acceptable values appear to be below 60m/s/s (see second picture below). Graph the Clip0, Clip1 and Clip2 values which increase each tim e one of the accelerometers reaches it’s maximum limit (16G).  Ideally these should be zero for the whole flight but low numbers (<100) are likely ok especially if they occur during ha rd landings.  A regularly increasing number through the log indicates a serious vibration problem that should be fixed

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This is an example of a vehicle that had position estimate prob lems due to high vibrations.The algorithm for calculating the vibration levels can be seen in the AP_InertialSensor.cpp’scalc_vibration_and_clipping() method but in short it involves calculating the standard deviation of the accelerometer readings like this: capture the raw x, y and z accelerometer values from the primar y IMU high-pass filter the raw values at 5hz to remove the vehicle’s movement and create a “accel_vibe_floor” for x,y and z axis. calculate the difference between the latest accel values and th e accel_vibe_floor. square the above differences, filter at 2hz and then calculate the square root (for x, y and z). These final three values are what appear in the VIBE msg’s Vibe X, Y and Z fields. 

# Earlier firmware versions Connect your Pixhawk/Flight controller to the Mission Planner Go to the CONFIG/TUNING | Standard Params screen and set the Log 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 h over (it doesn’t need to be perfectly stable or level) Disconnect the Lipo, reconnect your APM/PX4 to the mission plan ner Download the dataflash logs and after the download has completed, use the Mission Planner’s “Review a Log” buttong to open the latest file in the log directory (it’s last digit will be the Log number you downloaded so in the example above we dow nloaded Log #1 so thefilename will end in 1.log) When the Log Browser appears, scroll down until you find any IM U message.  Click on the row’s AccX and push Graph this data Left button.  Repeat for the AccY and AccZ columns to produce a graph like below.

Check the scale on the left and ensure that your vibration leve ls 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 Damping page for possible solutions. After all the above is complete, go to the Mission Planner’s st andard 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 require s significant CPU resources and it’s a waste to log these if they’re not really needed.
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.This article shows how to perform radio control calibration usi ng Mission Planner

. Contents [ hide ] 1 Overview 1.1 Transmitter configuration 1.2 Channel mappings 2 Preconditions 2.1 Safety first 2.2 Centre trims 2.3 Connect autopilot and turn on receiver 3 Calibration steps 

## Overview RC transmitters are used to control vehicle movement and orient ation. Copter and Plane minimally control throttle, pitch, roll and yaw, while on Rover we just c ontrol throttle and roll. Each of these control signals are mapped to transmitter stick/switch(s) and in turn t o autopilot channels from the connected receiver. Calibrating each of the transmitter controls/channels is a stra ightforward process – simply move each of the enabled sticks/switches through their full range and record the maximum and minimum positions. 

## Transmitter configuration There are two main transmitter configurations: Mode 1 : left stick controls pitch and yaw, the right stick will contr ol throttle and roll. ArduPilot > Copter > common-Radio Control Calibration in Mission Planner 

# Radio Control Calibration in Mission Planner Copter

EnglishCopter:

Note: Mode 2 : left stick controls throttle and yaw; the right stick will co ntrol pitch and roll.

Transmitter (Mode 1): Recommended Channels Transmitter (Mode 2): Recommended Channels 

## Channel mappings
Copter default channel mappings are: Channel 1 : Roll Channel 2 : Pitch Channel 3 : Throttle Channel 4 : Yaw Channel 5 : Flight modes Channel 6 : (Optional) Inflight tuning or camera mount (mapped to transmi tter tuning knob) Unused channels can be mapped to control additional peripherals

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The default channel mappings can be changed using the instructi ons in RCMAP Input Channel Mapping

. Once you’ve calibrated the flight mode you can use the instruct ions in RC Transmitter Flight Mode Configuration to specify which vehicle modes are enabled by each switch posi tion.Note: 

## Preconditions Safety first For safety reasons you should disconnect the battery and/or rem ove propellers before preforming radio calibration. 

## Centre trims Centre trims in manual RC mode before preforming RC calibration . If trims are not centred you may need to do the RC calibration again after you have used the veh icle (this is easy to do at the field). Trims are centred when a moving vehicle does not change directi on/speed/orientation when travelling hands-off with all controls/sticks in neutral positi ons. If there is any deviation in direction, speed or orientation, adjust the associated servo to compensate

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## Connect autopilot and turn on receiver Connect the autopilot via USB and turn on your RC transmitter. Verify that the transmitter is bound to the receiver (the receiver displays a solid green light) and th at it is set to use the correct model for your vehicle. Open Mission Planner’s INITIAL SETUP | Mandatory Hardware | Radio Calibration screen. If your RC receiver (Rx) and transmitter (Tx) are bound, you should see the green bars move when you move the transmitter sticks.Tip: Mission Planner: Radio Calibration Screen (Copter) If the bars are not moving then check what LED lights the recei ver is displaying: no lights – may indicate that it is incorrectly wired to the au topilot (look for connectors that may have been inserted upside down). red or a flashing green light – may indicate that your RC trans mitter/receiver need be bound (see the manual that came with your RC equipment for instructions). a solid green light – recheck the autopilot is connected to the Mission Planner and if the bars are still not moving, try clicking on the Calibrate Radio button. 

## Calibration steps 1. Open Mission Planner’s INITIAL SETUP | Mandatory Hardware | Radio Calibration screen. 2. Click on the green Calibrate Radio button in the lower right of the window. Mission Planner will display a prompt to check radio control eq uipment is on, battery is not connected, and propellers are not attached. Select OK

.Tip:

Mission Planner: Select Calibrate Radio and OK to begin calibra ting. 3. Move the control sticks and toggle switches on your transmitter to their limits of travel and observe the results on the radio calibration bars. Red lines will appea r across the calibration bars to indicate maximum and minimum values:

Mission Planner: Input range marked with red lines The green bars should move in the same direction as the transmitter sticks (except for Pitch where the bars move opposite to stick movements – low val ues are forward, high values areback).  If the green bars move in the wrong direction, reverse them using your RC transmitter’s channel-reverse function (see your RC gear’s manual for guidanc e). You should also calibrate the channel you have selected for con trolling vehicle mode, and any other channels you have connected to the autopilot. 4. Select Click when Done when all required channels are set at the minimum and maximum positions. Mission Planner will show a summary of the calibration data. No rmal values are around 1100 for minimums and 1900 for maximums.

Mission Planner: Radio Calibration Results 5. Turn off your transmitter and disconnect the battery if it was connected.
Questions, issues, and suggestions about this page can be raise d on the APM Forum . Issues and suggestions may be posted on the forums or the Github Issue Tracker

.This article shows how to perform basic compass calibration.

Contents [ hide ] 1 Calibration steps 2 Additional information 3 Video demonstration 

# Calibration steps 1. Under Intial Setup | Mandatory Hardware select Compass . Select the correct orientation for your setup. 2. Ensure the Enable and AutoDec check boxes are checked 3. Click the Live Calibration button 4. Next select your autopilot configuration: For Pixhawk and PX4, select the option Pixhawk/PX4 (with the image of the Pixhawk). For APM 2.6, select APM with External Compass (with the image of the GPS with compass module). These options will automatically enter the correct orientation for the board. Ensure that you have mounted the GPS with Compass with the arrow facing toward the front of the vehicle and in the same direction as the arrow on the autopilot. ArduPilot > Copter > Compass Calibration in Mission Planner 

# Compass Calibration in Mission Planner Copter

EnglishMission Planner: Compass Calibration 5. A window should pop-up informing you that you have 60 seconds in which to rotate the APM/PX4 around all axis, press OK 6. A countdown window should appear to show that the Mission Planner is collecting compass data 7. During these next 60 seconds you should hold the copter in the air and rotate it slowly so that each side (front, back, left, right, top and bottom) point s down towards the earth for a few seconds in turn.

Compass Calibration Positions (Copter) 8. Upon completion, another window will pop up showing you the new offsets that it calculated. 9. For PX4 and Pixhawk , values may be greater than 150 and less than -150. Press OK

. 10. For APM , as long as all three values are between -150 and 150 the offs ets are good.  Press OK

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# Additional informationMore details on this and other compass set-up procedures “ compassmot ” can be found in Advanced Compass Setup

. General discussion on magnetic interference and ways to reduce it can be found in Magnetic Interference

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# Video demonstration Video demonstration of compass calibration. 

### AC 3.0 "Live" Compass Calibration

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.This article describes the glitch protection mechanisms used to trigger GPS Failsafe.

Contents [ hide ] 1 Overview 2 Glitch Protection – Default 3 Glitch Protection – EKF 

# Overview GPS Systems can occasionally drop the signal or provide signifi cantly inaccurate position information (aka “glitches”). While errors are more likely in c onditions where the GPS signal can bounce off multiple paths before reaching the receiver (multipa thing), errors can occasionally occur even with clear sky.
A GPS failsafe event will occur if GPS 3D lock or the position “Glitches” for at least 5 seconds while Copter is in a mode that requires the GPS (RTL, Auto, Loi ter, Circle, Position, Guided or Drift).  The GPS failsafe response can be set to Land or switch to AltHold mode (in AC3.1 and higher) so that you can retake manual control. Without GPS updates, the inertial sensors allow approximately 1 0 seconds of accurate position information but after this the horizontal position drift become s so large that the horizontal position cannot be maintained at all.  At this point if you sti ll have RC radio control it is recommended to take back control using Stabilize, Acro or AltHo ld as soon as possible. This article describes two forms of GPS glitch logic. The first is used by the default navigation ArduPilot > Copter > GPS Failsafe and Glitch Protection 

# GPS Failsafe and Glitch Protection Copter

Englishalgorithm for AC3.1 and 3.2. The second (EKF) can be used in AC 3.2, and is mandatory in AC3.3 and later. 

# Glitch Protection – Default AC3.1 and AC3.2 include GPS glitch protection which can help al ert the pilot to a bad GPS position, trigger a failsafe and reduce the incidents of fly-aw ays.  Glitches are detected by comparing the each new position update received from the GPS wi th a position projected out from the previous update’s position and velocity.

The new position is accepted as “good” if: 1. the two positions are within the GPSGLITCH_RADIUS (defaults to 5m). 2. the new position is within a radius that is 10m/s/s ( GPSGLITCH_ACCEL ) * dt * dt.  Where “dt” is the time difference between the two samples. During a glitch, “ Bad Position ” will be written on the ground station’s HUD 

# Glitch Protection – EKF AC3.2 introduced a new form of glitch protection, the ArduPilot Extended Kalman Filter (EKF)

.Note: AC3.3 Enables EKF by default, and it cannot be turned off. On A C3.2 EKF is turned off by default – but you can enable it to run on the faster boa rds (using 32 bit micros) by setting AHRS_EKF_USE = 1
. Glitch protection using the EKF works as follows: 1. When new GPS position measurements are received, they are compared to a position predicted using IMU measurements. 2. If the difference exceeds a statistical confidence level set by EKF_POS_GATE , then the measurement won’t be used. 3. While GPS measurements aren’t being used, a circle defined by an uncertainty radius grows around the predicted position. The rate at which this radius gr ows is controlled by EKF_GLITCH_ACCEL . This is similar to the circle defined by GPSGLITCH_ACCEL , the difference being it is centered around the trajectory predicted by the IMU rather than previous GPS measurements. Because this allows for deviations i n trajectory due to maneuvers, the default value for EKF_GLTCH_ACCEL is smaller at 1.5 m/s/s. The acceleration growth of the circle is also increased when the vehicle is acce lerating or turning to allow for the increase in IMU errors during maneuvers. 4. If subsequent GPS measurements fall inside the circle, they will be accepted and the circle is reset back to the minimum radius controlled by EKF_POS_GATE
. 5. If the GPS glitch is large enough and lasts long enough, the GPS measurements will continue to be rejected until the circle radius exceeds a value set by EKF_GLITCH_RAD
. When this happens, an offset is applied to the GPS position so that it matches the estimated vehicle position and the GPS positions are used again. The GPS offset is then reduced to zero at 1 m/s. This means that large long duration glitches wil l cause the vehicle to drift at a 1 m/s rate. This is slow enough to give the operator plenty of time to react.
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