R3 Production Schedule, CAN Bus Improvements, Robotics Demo

A project log for Tinymovr Motor Controller

Affordable, precise, integrated motion control for robotics

YannisYannis 02/23/2020 at 21:290 Comments

The ongoing health crisis in China has affected PCB production and induced significant delays in PCB manufacturing and assembly. PCBWay, the manufacturer of Tinymovr prototypes, has announed delays of up to 30 days for small batch prototype runs. This is in addition to potential delays in shipping that are likely to be encountered.

Even though design of Tinymovr R3 is complete and has been carefully reviewed, I've decided to postpone sending the board to be manufactured until things settle down a bit and regular schedule is restored. This should incur a delay of about a month or so, which, in addition to a month between submitting design to receiving prototypes, should place the next round of Tinymovr boards in my hands late April 2020.

Taking advantage of this intermission, I've been working on a few improvements on the comms-side of Tinymovr, implementing a better CAN-Bus protocol that allows dynamic endpoint maps much like ODrive does. This goes in hand with an application I've been developing for interfacing and configuring Tinymovr from a PC/Mac, Tinymovr Studio. 

As soon as I achieve some progress in this, I'm planning a robotics demo as a follow up to demonstrate application of Tinymovr. The demo will feature a 2DOF robot leg that uses Tinymovr R2 in both DOFs, with daisy-chained power and comms.

Here's a preview of the mechanical assembly, which is almost ready:

This is a dual-belt-in-series arrangement that is heavily influenced by the Solo quadruped robot of the Open Dynamic Robot Initiative. The belt transmission achieves a 1:10 reduction in a compact package that fits well to the elongated form of the leg itself. The plan is to have Tinymovr R3 integrated in the leg assembly, right opposite the motor, where the encoder magnet is found. The first order of things is to get some simple kinematics working, and following that maybe try to implement some dynamic movements such as jumping.

Stay tuned for more updates!