This expansion board supports the for Microbit mainboard and is compatible with the control board. It supports USB power supply and battery box power supply, and has its own power switch. The lower left corner of the expansion board is the motor interface of M1 and M2. There are 11 alligator clip interfaces at the top and bottom, of which the bottom one is the Microbit mainboard alligator clip interface, and the upper alligator clip interface of the control board is also compatible with the bottom one. USB power supply port (5V) Battery box power supply port (5V-9V) Power switch UART protocol port 11C protocol port Anti-slip socket seat Motor driver chip M1 motor interface (P8 and P10) M2 motor interface (P9 and P15) Lead out all 10 ports, expand multiple 3.3V and GND ports to facilitate power supply for multiple modules The motherboard for Microbit alligator clip interface is compatible with the control board Alligator clip interface for control panel Positioning holes Colour:Black Material:PCB Due to different batches, there may be differences in product appearance, color, and printed text, which not affect the use. Package Contents: 1 x Expansion Board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.