Friday 12th March 2021
I stumbled across the webpage for Bittle by chance and ordered a Bittle and BiBoard from the Indiegogo site the next day (ordered on 6th February 2021).
Being an impatient sort of person, I decided to try and make some parts and get a Micro Python board (Raspberry Pi Pico) for control of movement, while I wait for my Bittle in the post.
Still anxiously waiting, but now got to the point where I can share some photos of the things I have done so far.
I use OpenSCAD to make the 3D printed parts and Pico Python for the control.
I would like to point out I have NO previous robotic knowledge and up till February never printed a single 3D item on any 3D printer, so this is all very new to me.
I saw the thread written by 'Aparatum' and I was blown away with the stunning images posted,.... unfortunately mine are not in the same class, but I am learning and always making changes and improvements....
I am now working on some Pico Python scripts. This may take a couple of weeks (hobby time whilst working full time) but I will update if there is anything good enough to put here.
I will also put some videos here when I actually get it walking.
David.
Thursday 1st April 2021
Robot mechanics now finished and stable (no jitter or oscillations on servos) so now only working on Circuit Python for control.
I can strongly recommend Raspberry Pi PICO control boards to anyone with a Bittle or Nibbles to use for Circuit Python programming to control their Petoi Robot!
The PICO is cheap and great fun as well as a superb method of learning Circuit Python.
This is my first piece of Python code for servo control. It can be found and downloaded at:
github - search for "muamp/quadruped"
'MUAMP_quadruped.py' is the main file containing setup information and functions used to control the servos.
'proper_test.py' and 'proper_test_all.py' are examples of how to use the functions.
Just as a quick example, below is 'proper_test.py'
(looks better in colour and easier to read on the github website)
# ****************************** python code *******************************************
# MUAMP example to show how easy it can be to use
# Circuit Python on a Raspberry Pi PICO
# to control the servos on Bittle (or equivalent, like MUAMP Quadruped)
import time
from MUAMP_quadruped import instant, travel
# Initialise Front Left knee to 90 degrees.
instant("FL_knee")
# travel from 90 to 120 degrees, with 0.02 sec delay between each degree step.
travel("FL_knee", start = 90, end = 120, speed = 0.02)
# Instantly jump to position 130 degrees and then travel to position 30 degrees
# with 0.02 seconds delay between each one degree travel.
travel("FL_knee", 130, 30, 0.02)
# wait one second.
time.sleep(1)
# Instantly travel to 70 degrees and stop
instant("FL_knee", 70)
# ******************************* end ***************************************************
This JPEG is from my notes showing the leg positions relating to various inputs in angle of degrees. Both left and right are same for angle settings!
David.