Introduction - If you have any usage issues, please Google them yourself
The 51 microcontroller press 4* 4 button makes press the button on the digital LED display. P1 port digital tube-shaped mouth, PO.O-P0.3 bit digital tube mouth, P2.0-P2.3 4* 4 keyboard column lines, P2.4-P2.7* 4 keyboard line line.