This expansion board not only leads to 9 micro:bit onboard GPIO interfaces, but also comes with 4-way motor drivers and 8 servo interfaces. The 4-way motor drivers can be repurposed and used as 2-way stepper motor drivers.
The micro:bit Driver Expansion Board adopts an IIC external drive chip to control the motor and servo motor, only takes up two IIC pins and can complete the motor and servo dual control without occupying other resources. Using an HR8833 motor driver, the maximum continuous operating current is 1.5A. It can drive the ordinary small motor and N20 mini metal motor. Each motor port comes with a positive and negative rotating indicator to identify the motor running direction conveniently, which is very suitable for students and makers to create small projects. Both the extended GPIO and the servo interface use the DFRobot-Gravity standard interface, supporting a large number of modules and sensors. The servo interface is directly connected to the Vin power supply, thus increasing the supply current which can support multiple servos to work at the same time.
This expansion board supports 3.5V to 5.5V power supply. It provides a DC 2.1 plug and a wiring terminal that can be connected directly to three dry battery boxes. It also comes with a USB to DC 2.1 adapter cable, which can be powered by a power bank and is more economical and environment-friendly.