一个基于串口的树莓派ps/2 Linux驱动.PS/2的DATA线接串口的RX线，PS/2的CLK空置。用前要测试键盘的频率。-Using two resistors, a blue LED, a few other bits, and a kernel module you can use a PS/2 keyboard by connecting it to the Pi serial port.

This works because I have found that you can read a keyboard without using the keyboard clock line if you use a serial port running at a custom speed. This works so long as the keyboard clock period is regular, which I have found to be the case with all keyboards I have tested