PLEN5Stack Assembly Manual
PLEN Project Company
2020/2/6

1 / 61

Table of Contents
1. Cautions on Assembly. . 3
2. Table of Contents
1. Common Parts. . . . . . . . . . . . 4
2. special kit. . . . . . . . . . . . . . . . 5
3. About the angle of Servo horn. . 6
4. Assembly
1. Preparation. . . . . . . . . . . . . . . . . 8
2. Switch board assembly. . . . . . . . 9
3. Circuit board and battery wiring. . 11
4. Servo motor set-up. . . . . . . . . . . 165. Assembling the Thighs. . . . . . . . 19
6. Attaching leg parts. . . . . . . . . . . . 23
7. Shoulder parts assembly. . . . . . . 27
8. Arm parts assembly. . . . . . . . . . . 31
9. Servo xer attachment. . . . . . . . . . 35
10. Control board wiring. . . . . . . . . . 38
11. Head part assembly. . . . . . . . . . . 41
12. Chest assembly. . . . . . . . . . . . . . .46
5. Motion check1. Let's walk the PLEN5Stack!. . . . . . . . . 51
2. How to adjust ServoMotor position
6. How to charge battery. . 52
7. Firmware Installation
8. Appendix
1. PLEN5Stack servo numbering. . . . . .
2. Control board terminal labelling2 / 61

1. Cautions on Assembly
There will be some steps where force is necessary.
Please take the proper measures and precautions to not hurt yourself or damage the partsand follow the instructions as described.
You will need a phillips screwdriver (+ head) for assembly.
Please use the provided pictures as a reference during assembly.
Please be aware that the colours and/or appearance of some parts in the provided pictures
and those provided may be slightly diﬀerent.
The required program for the M5Stack has already been included.
How to install page is [7. Firmware Installation]
PLEN5Stack https://github.com/plenprojectcompany/PLEN5Stack
When assembling the servo motors, the initial rotational position of the gear on the motors isimportant.
The assembly instructions includes initial positioning for the motors.
Please ensure all motors are properly set.
When setting the servo motors, make sure you wait at least 2 seconds after turning thepower switch on until the servo motors automatically set to their initial position.
If the servo motors do not move after 2 full secods, please if check they are connected
properly.

3 / 612. Contents list
2.1 Common Parts
1. M5Stack
2. Battery
3. Control Board
4. Switch Board PCB
5. Servo Motors x 8
6. Head Board Cable
7. Power Cable
8. USB Cable
9. Head Parts(top, bottom)
10. Chest Parts
11. Servo Bracket
12. Servo Fixer
13. Back Parts
14. Switch Board Holder
15. Shoulder Parts
16. Arm Parts×2
17. Thighs Parts × 2
18. Legs Parts × 2
19. Black Screw x 4
20. Silver Screw × 7
21. Servo Horn × 6
22.
23.
24. Label Sticker
25. head board
26. Connector tool

4 / 61

Contents list

5 / 61

3. About the Servo motor
3.1 Connector orientation
1. There is a direction in the connector of the servo motor. Make sure that the white cable is onthe inside.

Connector orientation

6 / 61

3.2 About the angle of Servo horn
1. Body balance is important for biped robots. but, since servomotors have individual
diﬀerences in rotation angle, it is necessary to absorb the individual diﬀerences by the servo
horn attached to this.
Therefore, the angle of the servo horn needs to be precisely adjusted. If this adjustment is
not successful, you will not be able to walk or fall easily.
Here we will explain how to make this adjustment.
2. The servo horn has a slight oﬀset between the inner serration and the front cross.
Therefore, when rotating the cross of the servo horn by 90 degrees, there is a point where
the cross is just horizontal.
Find this and ﬁx the servo horn.
3. As a method other than servo horn adjustment, a method to adjust by program is alsoprepared. (Coming soon)
The shoulder parts are integrated with the servo horn and can not be rotated by 90 degrees,
so they need to be adjusted in the program.

servo horn ﬁx image

7 / 61

4. Assembly
4.1 Preparation
Necessary items
1. Servo Motors x8
2. Label stickers or Circular Stickers
3. PenNecessary items

ProcedureFix the servo number stickers to each Servo motor cable.Write the numbers 0-7 on eight stickers
and place them Attach the sticker in a half-folded form to the servo motor cable.

Sticker placement
8 / 61

4.2 Switch board assembly
Necessary items
1. switch board set (switch board PCB, switch board holder, screw x2)

Necessary items

9 / 61

Procedure
1. Align the circuit board and plastic part2. Screw in the circuit board using the two screws at the corners

10 / 614.3 Circuit board and battery wiring
Necessary items
1. back part2. switch board
3. battery
4. control board
5. M5Stack
6. power cable

Necessary items

11 / 61

Procedure
1. Connect the power cable to the switch board

2. Insert the switch board into the back plastic part with the switch and connector going
through the appropriate holes as shown in the picture.

12 / 61

3. Connect the battery to the switch board following the below reference picture.

4. Connect the control board and switch using the power cable. The connectors are diﬀerent soplease ensure the correct connector slides smoothly into the pins.
※ It is necessary to remove the power cable at the time of "Control board wiring" mentionedlater. In this case, since it is hard to remove the cable from the connector, for children andpeople with weak force, use the supplied connector tool. This is a tool to makeit easy to remove by holding this tool between the power cable and the connector.

13 / 61connector tool use example
5. Plug in the M5Stack to the control board.

14 / 61

6. complete set of board assembly is seen below

15 / 614.4 Servo motor set-up
Necessary items
1. Servo motors ×4 (numbers 0,1,4, and 5)
2. Servo bracket

Necessary items

16 / 61

Procedure
1. Orient the servo bracket such that the long back is horizontal and towards the back wheninserting the servo motors.
The side of the bracket with this long bar in the middle is the "back" of the part andconcordantly the back of the robot.
Insert servo motor #0 into the servo bracket as shown. This will be the robot's left arm.
Be careful not to have the cable of servo motor #0 pinched between the motor casing andplastic parts when assembling.
Have the servo motor cable come out the "front" side of the bracket.

2. Insert servo motor #4 following the same procedure as #0 on the opposite side of thebracket.

17 / 61

3. Again, be careful not to have the cable of servo motor #1 pinched between the motor casing
and plastic parts when assembling.

4. Insert servo motor #5 following the same procedure as #1 in the last available position in
the bracket.
Ensure all servo motor cables are coming out the "front" face of the bracket.

18 / 614.5 Assembling the Thighs
Necessary items
1. The previously assembled servo bracket with servo motors.
2. The previously assembled control board\batteryswitch board
3. Thigh plastic parts ×2
4. Servo horn ×2
5. Screws ×2

Necessary items

19 / 61Procedure
1. Ensure the switch board switch is in the oﬀ position.
Connect servo motors #1 and #5 to the control board pins as shown.
The servo motor pins numbering is given in the Appendix 5.2 picture.
When connect the motors into the pins, ensure that the black (ground) cable is towards theoutside of the control board.
Turn the switch on the switch board on.
*if you have not installed ﬁrmware, see [7. Firmware Installation].

2. The servo motors should rotate automatically to their initial position.

20 / 61

3. Attach the servo horn plastic parts to servo motors #1 and #5 as shown in the photo.
Ensure the axis of the + on the horn is aligned with the edges of the servo motors.

4. Orient the servo bracket such that the bar across the center of the bracket is horizontal andat the back of the assembly.
The orientation in the photo below shows the bracket such that the robot's front is being
looked at and the head is on top.
Attach the plastic thigh parts onto the servo horns as shown, such that the bump on theplastic parts are pointing in the same direction as the "front" of the servo bracket.

21 / 61

5. Fix the thigh parts to the horn with the screws.

6. After fully screwing in each of the thigh screws,
remove the servo cables from the control board.

22 / 61

4.6 Attaching leg parts
Necessary items
1. body sets
2. circuit sets
3. servo ×2 (3,7)
4. legs ×2
5. servo horn ×2

Necessary items

23 / 61

Procedure
1. Insert servo motors numbers 3 and 7 into the thigh parts as shown.
The gears of the servo motors will be pointing towards the "back" of the robot.

2. Connect the servo cables for motors 3 and 7 into the control board.
Servo motor number 3 is to be placed as the robot's left leg.
Motor number 3 is connected to the corresponding pin set #3 again with the black (ground)cable towards the outside of the control board.
Repeat for motor #7. Turn the switch board back on.

24 / 61

3. The servo motors should rotate automatically to their initial position.

4. Similar to servo motors #1 and #5, attach the servo horns to each servo motor such thatthe axis of the + on the horn is aligned with the edges of the servo motors as closely aspossible.

25 / 61

5. Attach the feet plastic parts while paying attention to ensure the wider side of the feet are
towards the outside of the robot.
Insert the + side of the foot into the servo horn and then insert the opposite side of the footinto the bump on the front side of the thigh.
*This may take some strength.

6. After ﬁxing the feet to the servo motors,
unplug the servo motors from the control board and turn the power switch oﬀ.

26 / 614.7 Shoulder parts assembly
Necessary items
1. body sets
2. circuit sets
3. shoulder ×2
4. screw ×2

Necessary items

27 / 61

Procedure
1. Connect servo motors #0 and 4 from the servo bracket into their respective pins on thecontrol board and turn the power switch on.

2. The servo motors should rotate automatically to their initial position.

28 / 61

3. Insert the shoulder parts into servo motors 0 and 4 such that the ﬂat edges are aligned withthe servo motor as closely as possible.
The wider side of the shoulder parts with the + cut should be towards the back of the robot.
Screw in the plastic shoulder part into the servo motor.

4. Repeat the previous step for the opposite shoulder

29 / 61

5. Unplug the servo motors from the control board and turn the power switch oﬀ.

30 / 614.8 Arm parts assembly
Necessary items
1. body sets
2. circuit sets
3. arm ×2
4. servo ×2 (2,6)
5. servo horn ×2

Necessary items

31 / 61

Procedure
1. Place the servo motors #2 and 6 into the plastic arm parts such that motor #2 is the robot'sleft arm.

2. Directly connect servo motors #2 and 6 into their respective pins on the control board andturn the power switch on.

32 / 61

3. The servo motors should rotate automatically to their initial position.

4. Attach the servo horns to each servo motor such that the axis of the + on the horn is alignedwith the edges of the servo motors as closely as possible.

33 / 61

5. Insert the left and right arms into the shoulder pieces lining up the servo horn with the cut +shape on each shoulder.
*Ensure thearms are inserted pointing down.

6. After ﬁxing the arms to the shoulder parts,
unplug the servo motors from the control board and turn the power switch oﬀ.

34 / 614.9 Servo ﬁxer attachment
Necessary items
1. Body assembly set
2. Servo ﬁxer part

Necessary items

35 / 61

Procedure
1. Pass the cables of the eight servo motors through the servo bracket and through front asshown.

2. The cables of motors #3 and 7 are passed through the lower hole of the bracket, and left
there for later.
3. Servo motors #1 and 5 are passed between the opening in the servo ﬁxer,
while the remaining cables are temporarily wrapped up around the top ofthe body to keepthem out of the way.
4. Attach the servo ﬁxer part so as to not catch and pinch any of the other servo motor cables.

36 / 614.10 Control board wiring
Necessary items
1. Battery assembly
2. Control board assembly

Necessary items

37 / 61

Procedure
1. Remove the M5Stack and the power cable from the control board.
Pass the power cable along with the servo motor cables from the back side through the front
hole in the body and reconnect the power cable to the control board again.

2. Put the battery into the back plastic part on top of the switch board and keep the battery
cable underneath the battery.
Attach the back plastic part to the back of the servo bracket.

38 / 61

3. Connect all servo motor cables following the appropriate order with servo motor number
matching pin number.

39 / 614.11 Head part assembly
Necessary items
1. body sets
2. head parts(top, bottom)
3. head board
4. head board cable

Necessary items

40 / 61

Procedure
1. Take apart the top and bottom plastic parts of the head

2. Connect the ﬁnal head-board control cable to the head-board

41 / 61

3. Unscrew the nuts on each LED down about 3mm.

4. Pass the head-board cable through the hole in the bottom side of the head plastic part.

42 / 61

5. Bend the LED legs 90 degrees such that the head-board is rotated up,and insert both LEDs into the semi-circular grooves in the bottom plastic heat part such thatthe nuts on each LED are on the inside of the head.

6. Align and place the top plastic head part onto the bottom part by ﬁrst passing the LED bulbs
through the top heat eye holes.

43 / 61

7. Insert the head-board cable through the top hole in the servo bracket and pass through thefront side of the body.
Insert the assembled head into the same hole to ﬁx the head to the servo
bracket.

8. Connect the head-board cable into the control board.

44 / 614.12 Chest assembly
Necessary items
1. body sets
2. chest
3. M5Stack
4. screw × 2

Necessary items

45 / 61

Procedure
1. Remove M5Stack from control board.
Pass the control board through the body part and bring it out to the front.

2. Attach the chest parts to the servo bracket body.

46 / 61

3. Screw the control board to the chest part

4. Insert the M5Stack.

47 / 61

5. Switch the robot on and conﬁrm if all servo motors have rotated and initialized.

6. Press the M5Stack A and B buttons to check that the limbs work. C button is blink the EYE
LED.

48 / 61

5. Motion check5.1 Let's walk the PLEN5Stack!
1. Press A Button to check if PLEN5Stack walks.
2. Enjoy PLEN5Stack!

49 / 61

6. How to charge battery
1. Connect PLEN5Stack ( back Switch Board ) and PC ( or USB charger ) withcable.
2. Charging : LED ON
3. Full charge : LED OFF

50 / 61

7. Firmware Installation
How to Install
1. Download (and install) Arduino IDE from arduino.cc website. (Choose your environment,then click "JUST DOWNLOAD" button.)
2. Add board manager URL: https://dl.espressif.com/dl/package_esp32_index.json
3. Add esp32 board
4. Add M5Stack library
5. Download this repository from here.
6. Open the ﬁrmware.ino using the Arduino IDE.
7. Click the upload button (that is like a right arrow).

51 / 61

Preliminary Arrangements
To write PLEN5Stack's ﬁrmware requires Arduino IDE ver.1.8.0 or above. Please download andinstall it before to do continued steps.

How to Download the Arduino IDE
Access the Arduino IDE download page, and then choose your environment.

Click “JUST DOWNLOAD” button. (You do not need to select donation menu.)

52 / 61

Setting the Arduino IDE1. [File] -> [Preferences]
2. Right button for Additonal Boards Manager URLs
3. Inpust the URL: https://dl.espressif.com/dl/package_esp32_index.json

53 / 6154 / 61

Install board
1. [Tools] -> [Boards:...] -> [Boards Managers...]
2. Input the [esp32] for Boards Managers
3. Instal the esp32

55 / 6156 / 61

Install libraly
1. [Skecth] -> [Include Library] -> [Manage Libraries...]
2. Input the [m5stack] for Library Manaber
3. Install the [M5Stack]

57 / 6158 / 61board select
1. [Tools] -> [Board:...] -> [M5Stack-Core-ESP32]
2. [Tools] -> [Port] -> Select the your Serial Ports (Port name is diﬀerent in eachenvironments.)

59 / 61

Installation Procedure
Download [PLEN5Stack] repository
1. Open “ﬁrmware.ino” (This is placed “ﬁrmware/” directory) with Arduino IDE.
2. Connect M5Stack to PC with USBTypeC cable.
3. Click the Upload[->] button.

60 / 61

Appendix
PLEN5Stack servo numbering

Control board terminal labelling

PLEN5Stack Support
If you have any questions, please contact one of the following
PLEN5Stack Slack community : http://u0u0.net/YJzp
PLEN Support : https://plen.jp/wp/contact/

61 / 61