- An STM32F103 does the heavy lifting when it comes to making the robot walk. It calculates locomotion, inverse kinematics, body rotation/translation and finally drives the servos. With a simple serial protocol, commands can be sent to control the robot directly. The serial interface is also what the Raspberry Pi Zero W is connected to. It is running an improved version of the software created for the wheeled Zerobot, which hosts a web interface for mouse and touch controls. On top of that, wireless gamepads are supported via pygame.
- Hardware-wise a custom circuit board holds the STM32, the PWM controller and a few other components while the Raspberry Pi Zero is plugged into the back of the PCB. The servos used are inexpensive EMAX ES08A II. Anything apart from the electronics and servos is 3D printed.
The whole project is heavily inspired by Matt Dentons incredible µBug, adopting its dimensions and proportions.
If I ran 2 PCA9685 16-Channel 12-Bit PWM Servo Driver boards, soldered all the connections to save space inside, how would the code need to be adjusted? Could I run one side of servos on one and then the other for the other side?
I am looking at these https://www.aliexpress.com/item/32811125110.html?spm=a2g0o.productlist.0.0.2062198cbAgki7&algo_pvid=7c697d51-54b3-4adb-bc02-9a070f00ac49&algo_exp_id=7c697d51-54b3-4adb-bc02-9a070f00ac49-25&pdp_ext_f=%7B%22sku_id%22%3A%2264583513452%22%7D&pdp_npi=2%40dis%21CAD%21%214.59%21%21%213.07%21%21%400b0a555416547028114402190e01ef%2164583513452%21sea
and I will add these capacitors https://www.aliexpress.com/item/1005004224701993.html?spm=a2g0o.productlist.0.0.4b116f33hX2KGo&algo_pvid=d363757a-56fe-4a3f-aed0-78f83a86da54&aem_p4p_detail=2022060808420210535781539639300004788250&algo_exp_id=d363757a-56fe-4a3f-aed0-78f83a86da54-30&pdp_ext_f=%7B%22sku_id%22%3A%2212000028439551966%22%7D&pdp_npi=2%40dis%21CAD%21%2117.94%21%21%21%21%21%400b0a556e16547029227774221e2a23%2112000028439551966%21sea
I also adjusted the stl files to fit this servo. https://www.aliexpress.com/item/1005003788629887.html?spm=a2g0o.productlist.0.0.f8a63242PyxXA1&algo_pvid=c26740ba-9d0d-4a04-8f9f-89da56f2e1e4&aem_p4p_detail=202206080854192194297164582840027421286&algo_exp_id=c26740ba-9d0d-4a04-8f9f-89da56f2e1e4-13&pdp_ext_f=%7B%22sku_id%22%3A%2212000027172151416%22%7D&pdp_npi=2%40dis%21CAD%21%2133.9%21%21%218.16%21%21%40210318cb16547036594631353e4493%2112000027172151416%21sea
I am looking at making this robot in my high school robotics class next year.