Simple NodeMCU 18 DOF Hexapod

20,993

45

77

Introduction: Simple NodeMCU 18 DOF Hexapod

About: Designer, Artist, Engineer

A hexabot robot is a mechanical vehicle that walks on six
legs. Since a robot can be statically stable on three or more legs, a hexabot robot has a great deal of flexibility in how it can move. If legs become disabled, the robot may still be able to walk. Furthermore, not all of the robot's legs are needed for stability; other legs are free to reach new foot placements or manipulate a payload.

Many hexabot robots are biologically inspired by Hexabot locomotion. Hexabots may be used to test biological theories about insect locomotion, motor control, and neurobiology.

Using 18 servos or 18DOF with 3 join per leg is flexible enough for a hexabot robot than 12DOF hexabot robot.

some of Hexabot hobot have a complex mechanism and schematic. in this design i try to make a simple design hexabot using common component that we can found in the market

Step 1: Time to Shoping

Step 2: Print and Assemble the Body Part

all the spider body part and claw can be download from

https://www.myminifactory.com/object/3d-print-7650...

or

https://www.thingiverse.com/thing:3130196

mandatory list of part u have to print :

  • 6x shield.stl
  • 3x coxa_A.stl
  • 3x coxa_B.stl
  • 3x tibia_A.stl
  • 3x tibia_B.stl
  • 3x femur_A.stl
  • 3x femur_B.stl
  • 1x Hex_body_short.stl
  • 1x Hex_cover_short.stl
  • 1x Ring.stl

The rest is optional...

Step 3: Connecting the Dot

This is all electronic schematic, basically all servos controlled by 32CH servo controller because it's already have micro controller in it. Just like arduino it's independence and can controlled using serial command from PS2 controller, PC or other device.

Step 4: 32CH Servo Controller

Features:

  • Operating voltage: 5v
  • Servo motor input voltage: 4.2V~7.2V
  • CPU: 32 bit
  • Baud Rate (USB):115200
  • Baud Rate (bluetooth/UART): 4800 、9600、19200、38400、57600、 115200
  • flash storage capacity: 16M
  • Red Indicator: CPU power indicator
  • Gree Indicator: servo motor indicator
  • Yellow Indicator: PS2 Wireless Controller
  • Mode Protocol: UART
  • Computer protocol: Support Single
  • Operating protocol: Support
  • Supper servo motor type: 9G~55G (3.3V~7.2V)
  • Online Operations Support: C51/ARM/DSP/Buletooth/Computer
  • Mode type: USB/UART/Offline Independent/PS2 wireless control

Cabling mapping :

  1. 5v power out (+) from UBEC
  2. Ground from UBEC and Mini Stepdown
  3. 5v power out (+) from mini step down
  4. to Wemos D1 mini G pin
  5. to Wemos D1 mini 5v pin
  6. to Wemos D1 mini RX pin
  7. to Wemos D1 mini TX pin
  8. (match the pin color with the servo cable color) to right front leg (pin 1 to coxa, pin 2 to femur, pin 3 tibia servo)
  9. (match the pin color with the servo cable color) to left front leg (pin 5 to coxa, pin 6 to femur, pin 7 tibia servo)

  10. (match the pin color with the servo cable color) pin 9 to claw servos (assemble the claw first)

  11. (match the pin color with the servo cable color) to left middle leg (pin 13 to coxa, pin 14 to femur, pin 15 tibia servo)

  12. (match the pin color with the servo cable color) to right middle leg (pin 17 to coxa, pin 18 to femur, pin 19 tibia servo)

  13. (match the pin color with the servo cable color) to left back leg (pin 25 to coxa, pin 26 to femur, pin 27 tibia servo)

  14. (match the pin color with the servo cable color) to right back leg (pin 29 to coxa, pin 30 to femur, pin 31 tibia servo)

Step 5: NodeMCU AP

The WeMos D1 mini is minimal ESP8266 wifi board

Using wemos D1 mini as WIFI AP we can send serial command to the 32 CH servo controller and independence become Web server AP for controlling the robot.

all we need just flash the nodeMCU board with the code attach and we can connect the smartphone to the nodeMCU AP and using web browser open http://192.168.4.1 and we can see all the command.

ModeMCU Pin mapping:

  1. to the 32 CH servo controller RX pin
  2. to the 32 CH servo controller TX pin
  3. from 32 CH servo controller G pin
  4. from 32 CH servo controller 5v pin

PS: I have fix (31/4/2019 update) some connection issue that appears before... such as hard to connect or page not render completely...and if u have a alot of error movement, please check your battery current... usually it because it running with not enough battery power...

So Have some fun with it...!! :)

Step 6: Initial Pose

IMPORTANT...!!

we need to set the initial pose for the spider.

  1. turn on the robot (at the first time maybe all the leg will be miss pose so for this step please release all the servo horn first)
  2. reattach the servo horn and adjust the coca, tibia and femur pose just like the picture abbove
  3. turn off and turn on again to make sure that all leg is in the right position

Step 7: Adding More Movement

After all finish, we can add more motion to the arduino code. I using RTrobot servo controller to make some movement and after we have the serial command for the servo, we can put it in the code with some code adjustment.

download here

or here @4shared for windows & linux only

PS Very very IMPORTANT :

all RX and TX from and to Wemos and Servo Drivers have to firmly connected, because looping routine always check "OK respond" from the 32 servo drivers. If servo driver not found and there is no "OK" respond, than program will be loop in "void the wait_serial_return_ok()"
This mistake will cause : - Cannot connect to the AP - Blank web page - Page loading progress not finish

Step 8: Sugestion...

  1. for power supply we also can use lipo 3s battery, i think 900mah is enough but u need to have lipo battery for charge it.
  2. if u want to put obstacle sensor and servos, u can connect the sensor to the one of the wemos d1 mini input pin, and the power from 32 CH servo controller G and 5V

Step 9: For Whom Have a Problem With Opening Web Page or Connecting to the AP

I HAVE FIX THIS ISSUE PLEASE DOWNLOAD IT AGAIN FROM STEP 5 ABOVE (fix @ 31-4-2019)

some of Wemos D1 mini clone have a bad or defect ESP, and it causing:

- Hard to connect to the AP

- Fail to open page

- Loading not finish

For more detail check my video above...

Step 10: Cable Organize...

Basically just do the u can do... But I can share I I have do... Here's the picture...

5 People Made This Project!

Recommendations

  • Potato Speed Challenge

    Potato Speed Challenge
  • Mason Jar Speed Challenge

    Mason Jar Speed Challenge
  • Bikes Challenge

    Bikes Challenge

77 Discussions

0
Hamish borwne
Hamish borwne

9 months ago

hey im having trouble finding the code for the servo controller do you think you could post it again? all i can get to download is the bug fix which dose not seem to be all the code??


0
MusaW
MusaW

Reply 9 months ago

this file (Hexapod310319_fix_connection_issue.ino) is not only the bug fix but all code include bug fix...

0
OspreyGozo
OspreyGozo

4 weeks ago

Hi,
I am able to connect to the Wemos and I can view the web interface on my phone. However, as soon as I attempt to do any movement, the light on the Wemos stops blinking and it looks as though everything has hanged. As there anyhing that can be done about it?

0
OspreyGozo
OspreyGozo

Reply 4 weeks ago

I think I finally got it to work. I changed "Serial.begin(115200);" to "Serial.begin(9600);" and in the Arduino IDE I changed to board to "LOLIN(WEMOS) D1 R2 & mini". Now the servos start working when I issue a command through the web interface.

4
n.saldunas
n.saldunas

7 months ago

Hi, what board you chose from the list in arduino ide, then importing the code to wemos? I'm getting web page with control buttons, but robot not moving then pushing them. What arduino ide libraries I should install? Do I need to do something with 32 ch servo controller board? Is this code the same as your v1 hexapod robot code? V1 hexapod robot code is not working at all for me, not opening web buttons. But still with this code I see buttons can push them but nothing happening.

0
OspreyGozo
OspreyGozo

Reply 4 weeks ago

I was having the same problem when I used "WeMos D1 R1". When I set it to "LOLIN(WEMOS) D1 R2 & mini" it started working for me. I also set the baud rate from 115200 to 9600 but I doubt this was the actual fix. I hope this helps.

1
FelipeM188
FelipeM188

Question 7 months ago

Hello my friend, Sorry again for the inconvenience, i was wondering If It ia normal to click on any Cell Key the BLUE wemos light goes out? Thankful

0
OspreyGozo
OspreyGozo

Answer 4 weeks ago

I think I finally got it to work. I changed "Serial.begin(115200);" to "Serial.begin(9600);"
and in the Arduino IDE I changed to board to "LOLIN(WEMOS) D1 R2 &
mini". Now the servos start working when I issue a command through the
web interface. Not sure which change made the difference. It is probably the latter but I mentioned the other just for completeness.

0
OspreyGozo
OspreyGozo

Answer 4 weeks ago

I am having the same problem. Did you find a solution?

1
lancemark76
lancemark76

Answer 4 months ago

I have the same problem with you. Did you fix it, if so, pls share it with me.

0
pathieu.anglade
pathieu.anglade

3 months ago


I created a remix version with a camera and all the code is in python on a raspberry pi zero w

PS : for all those who have a freeze problem, this comes from the driver card, you have taken the Chinese version USC 7.7 which does not work with speeds higher than 9600 bauds (this is the one I use in the video)

I can share my python code as well as the 3D plans for the camera if it interests people

I also created a software in C # allowing to control the servos with the Chinese driver card usc 7.70, I can also send you the code sources

there are still slight bugs to fix but please be indulgent I am a student I am not the level of mrusaW

0
MusaW
MusaW

Reply 2 months ago

that's is very impresive...

0
vasilgerasimov76
vasilgerasimov76

Reply 2 months ago

Меня очень заинтересовал ваш проект, а можно поделится версией ремикса с камерой, и весь кодом написаного на python для Raspberry Pi Zero W !!!!!!!

1
TomiH8
TomiH8

1 year ago

Hello. I have a problem with connecting to the AP. I'm going to upload the program pretty well to wemos. But if I connect with my smartphone and press a command, the AP stopped ... why? Servo board is well, servos too,... but communication between board=wemos=smartphone... no ... :( i tried cables and others... and nothing :/

0
MusaW
MusaW

Reply 1 year ago

do u separate between servo driver power and nodemcu board power?

0
TomiH8
TomiH8

Reply 1 year ago

yes, everything has divided power. I even bought another servo board for sure if the previous one was damaged. But there's nothing wrong with that either.

1
lancemark76
lancemark76

Reply 4 months ago

Hello Tomi, I have the same problem with you. Did you fix it? If so, pls share it with me.

1
TomiH8
TomiH8

Reply 4 months ago

nooo :( I still have this problem :( ...