I’m excited to announce new python bindings for communicating with moteus controllers! A simple example from the README:

import asyncio
import math
import moteus

async def main():
  c = moteus.Controller()
  print(await c.set_position(position=math.nan, query=True))
  await asyncio.sleep(1.0)

asyncio.run(main())

This code will try to locate an fdcanusb on your host and use it to communicate with controller with ID 1. All of those details can be customized through code depending upon how you construct things. The library is pure python, although it doesn’t work on Windows currently because it relies on an asyncio aware pyserial wrapper that doesn’t work there.

I’m working to improve the walking gait of the mjbots quad A1. In this iteration, I wanted to tackle an incremental step towards a more fully dynamic gait, but one that will still greatly increase the capability of the machine. As mentioned last time, the current walking gait cycles between all four legs, and then alternative opposing corner legs in order to move laterally. I’d like to keep that same basic structure, but be a bit smarter about what happens during the swing phase.

I’ve had a confusing mismash of development tools for the moteus servos for a while now.  My original development tool was in python, which worked just fine.  Coroutines allowed me to express complex asynchronous logic succinctly, the program itself was rather simple, and I could easily integrate it with matplotlib for plotting.  However, when looking to run this on the raspberry pi, I needed a newer python version than came with raspbian, which turned out to be a royal pain to get installed in a repeatable manner.  Thus I rewrote a portion of the moteus_tool in C++ and just used my normal cross-compiling toolchain to generate the binaries.  What I didn’t do was port the calibration logic, as the state machine required with standard boost::asio would have bloated the logic size by 5x, and I didn’t really need to calibrate servos from the raspberry pi ever.

While working to build a weight reduced moteus servo mk2, I reworked my outer housing CAM to do all the machining on the Pocket NC v2-50.  For this part I didn’t necessarily need any challenging workholding and since I could get the stock in tube form, there wasn’t an inordinate amount of material to remove either.

The one challenge is that when mounted in the Sherline Chuck, the mill can’t actually reach all the way to the edge of the part without hitting the X travel limit (which is why most of the other 100mm diameter parts I do are fixtured slightly off-center).  In this case I tackled the problem in two iterations.