The IES-SHIELD-STX4 is a four  channel 5V or 6-12V (jumper selectable) Unipolar stepper motor driver with advanced control features.
Specifically targeted at the Arduino UNO board user [all other Arduino boards supported] and the Raspberry-PI the STX4 features high speed I2 C communication for easy project integration and smooth speed control.
Once connected each stepper motor can be stepped in either direction a number of steps (with speed control), continually stepped (with speed control), stopped (with holding torque or completely off ), with selectable 1 or 2 phase excitation, by simply writing a value to an internal register over the connected I2 C interface.
The STX4 supports all 5-12V unipolar (5 wire) stepper motors (with a minimum winding resistance of 20R [250mA]) and also provides global activation of new stepper positions & movement complete registers for superior control.
The STX4 provides a high power regulator capable of supplying 5V @ 3A to the connected servos from an external Li-Pol or Ni-MH battery pack of 7.2 to 8.4V and a 5V @ 1A USB A power output to power an externally connected Arduino board or Raspberry-Pi.
Alternatively a jumper selection allows servos with a maximum 12V operating voltage to be used. The on-board I2 C pull-ups are jumper configurable to allow disconnection when connecting to the Raspberry-PI, which has its own pull-ups