Digital

USB keyboard and mouse emulator via serial port

A concise guide to the CH9329 from Nanjing Qinheng Microelectronics — pinout, operating modes and serial communication modes for emulating a USB keyboard, mouse and custom HID device.

USB HID
UART
USB keyboard
USB mouse
emulator

TM1637Digital

LED display and keypad driver

A concise guide to the TM1637 from Titan Micro Electronics — pinout, internal operation and the two-wire communication protocol used to drive 7-segment displays and read a keypad matrix.

led driver
7-segment
two-wire
keypad scan
serial protocol