Quote by Matt:
If you must use Tetrix motors, you should look for an alternative controller for them. Looking at the Arduino drivers for the TETRIX MAX DC Motor Expansion Controller2, it looks like it’s an I2C device, which means you could probably control it from a BrickPi3 (connected to a sensor port, or even to the Grove I2C port).
Can Dexter provide a C driver for the TETRIX MAX DC Motor Expansion Controller2? Unfortunately I have not the skills to write C++ code by my own and I do not understand Arduino C++ code and how to port it to BrickPi3 code. I can only program in plain ANSI C, but even then writing driver code for i2c or anything also ever has been far beyond my skills (that was already so in the times of NXC and even later for Arduino Wiring).