SimpleFOC42B

The SimpleFOC42B is a driver board, that could be directly attached onto the back of a NEMA17 stepper motor. It is designed to run the SimpleFOC software. Additionally you will need the SimpleFOC drivers: https://github.com/simplefoc/Arduino-FOC-drivers

To control the board, one could either use a serial interface of a SPI port. Each port has two connectors, that allow daisy-chaining multiple boards. If space in the project is rare, one could just snap off the additional connector. You could program the board via J-Link, additionally (e.g. for serial outpot), the board has a micro USB port.

It's possibe to use the board also as a driver for other form factors than a NEMA17 stepper - e.g. a NEMA8 stepper: Just plug in an external magnetic encoder into the SPI connector.

The SimpleFOC42B is equipped with the STM32F103CBT6 as MCU. The chip has the same pinout as the STM32F103C8T6, but more flash memory - something that comes handy, when realizing more complex programming.

The used magnetic encoder "MT6835GT" is quite expensive in comparison to the normally used AS5600. But it comes with a 12 Bit resolution.

For future versions of SimpleFOC, the board also has current sensing implemented.

You find the complete pin out in the graphic attached.

A special thanks goes to the community of SimpleFOC on their discord server for all the help in designing this board - especially to R. Unger for his inexhaustible knowledge and his time.