Grayhound quadrupedal robot wiring

Grayhound Quadruped: Wiring, wiring & more wiring!

It's been a while since I've made an update on the robot...

It’s been a busy summer, so I haven’t had much time to keep everyone updated, but rest assured progress is being made.

Just tackling some wire management on the Grayhound quadruped. Ran into some issues with the original i2c interface on the Pi 4, so I’ve gone a different route than originally planned.

The actuators originally used the i2c bus to communicate with the mainboard, this approach actually has worked flawlessly in the past builds, but this time around I’ve been experiencing way too many issues on the Raspberry Pi 4 and it’s known i2c bugs.

The solution for now is use PWM signaling to handle position commands. I ran some tests for about 1.5 weeks using a PCA9685 module, and surprisingly it checks out, so I’ve been spending much of my time re-doing all of the wiring progress I had achieved.

This presents actually a few opportunities, as I can re-use old code from my first robots, as well as boilerplates that are already working for other folks, so this actually turned out to be a happy accident!

I plan on doing a quick write-up of the strange issues I was having with Raspberry Pi i2c bus, as it appears there is a handful of known bugs with the systems. The Pi 3 tests  of course worked flawlessly, but for some reason the 8GB model of the Pi 4 seems to require a lot more workarounds to make it behave predictably.

Anyways, just wanted to post a quick update, I will get into more details soon!

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