The first version of my stepper motor controller was a build with the standard L29 and L298 schematic. With this design two small stepper motor could be controller. The design was split up into the output stage, which could also directly be used via the STEP/DIR pins, and a controller which could be connected via I2C to control the motors.

With the controller board it is also possible to connect two rotary encoder which are mounted on the motor axis. With this the position of the motor is known even when the stepper motor looses steps. Both boards can be mounted above each other to have a compact stepper motor controller. Multiple of these stepper motor controllers can be connected to one I2C bus.

Each of the two motor can be given a number of steps and together with a frequency for the steps via the I2C bus. For each motor thee is a list of 32 entries with to save those steps.