Introduction The BBC micro:bit is a powerful handheld, fully programmable computer designed by the BBC. It is designed to encourage children to actively participate in technology activities such as coding and electronics. It features a 5x5 LED matrix, two integrated buttons, compass, accelerometer and Bluetooth compatibility. It supports the PXT graphical programming interface developed by Microsoft and can be used under various operating systems such as Windows, MacOS, IOS, Android, etc., without the need to download an additional compiler. The Keyestudio micro:bit relay breakout board integrates 4-channel 5V relay modules and is fully compatible with the micro:bit development board. Just plug the micro:bit into the keyestudio relay expansion board, and then input DC5V voltage into the relay VIN/GND port to work. It is very simple and convenient. The 4-way relays on the distribution board are active at high level. The control terminals are connected to P4, P3, P7, and P6 of the micro:bit development board respectively. Just control the output levels of P4, P3, P7 and P6 to control the on and off of 4 relays.