* 40 V if regulator is disconnected
The minimum operating voltage for all four versions is 6.5 V, while the maximum operating voltages are given in the above table. The board also includes an integrated 5 V, 2.5 A switching step-down regulator that can be used to power the Raspberry Pi it is plugged into, enabling operation from a single power supply.
The driver’s default configuration uses six GPIO pins to control the motor drivers, making use of the Raspberry Pi’s hardware PWM outputs, and it uses two additional pins to read status outputs from the drivers. However, the pin mappings can be customized if the defaults are not convenient, and pins for current sensing and limiting are accessible on the board for more advanced applications.
The board matches the Raspberry Pi HAT (Hardware Attached on Top) mechanical specification, although it does not conform to the full HAT specifications due to the lack of an ID EEPROM. (A footprint for adding your own EEPROM is available for applications where one would be useful; pull-ups on SDA, SCL, and WP are provided.) It is not practical to use this expansion board with the original Raspberry Pi Model A or Model B due to differences in their pinout and form factor.