pyservo42c

This is a library for interfacing to the MKS Servo42C closed-loop stepper motor via UART.

See https://github.com/makerbase-mks/MKS-SERVO42C for details on the hardware.

Note the serial protocol spec claims to include a checksum at the end of response messages. This doesn't seem to be true in practice. Also the set-angle command only accepts two bytes in the "pulse number" field, not the four bytes the spec claims.

Many of the commands are implemented, but not all. Pull requests encouraged!

Modules

servo42c

This provides methods that generate and consume byte arrays for commanding the servo and interpreting results.

servo42cTCPUartBridge

This wraps servo42c and provides an interface to a UART-over-TCP bridge, used for testing.

servo42cUart

This wraps servo42c and provides a direct interface to a UART port.

Implementation notes

TCP UART

For fun, and to avoid trying to map to a windows COM port from WSL, I used an ESP32 running esphome and esphome-stream-server. This gives you a wireless UART port over wifi! Works great.

Raspberry Pi

I tested this interface on an Raspberry Pi 3, but it should work on basically anything. I used raspi-config to enable the /dev/ttyS0 UART port and used pins 6, 8 and 10 for GND, TX and RX.