RAPS128 was designed with 32-bit electronics in mind, it is based on the THB6128 chip and has a maximum of 128 micro steps per full revolution. Even though it is best suited for 32-bit controllers, it is still 8-bit compatible. 8-bit systems are too slow for 64 or 128 microsteps, therefore the recommended maximum is 32 microsteps for an 8-bit board.

The RAPS128 stepper motor driver can handle a motor voltage of 10 – 25V, with a maximum current output of 2.2A. The V-Ref and Motor decay are adjustable via two potentiometers. The stepper driver has sleep and boost mode, as well as short circuit shutdown.

The size of the RAPS128 driver corresponds to the widely used Pololu drivers, the pinout is also compatible, but not identical. Because of the slight differences with Pololu, in the firmware, the stepper enable pins should be set to ‘Non Inverting’ i.e Active High, this usually means changing the ‘0’ to a ‘1’ for the axis which these drivers are used on.

RAPS128 comes with a large heatsink pre-installed, this will keep it extremely cool during operation.