This is an I2C or Serial user interface comprising a 16x2 LCD COG lcd display and a 25 way keypad interface. There is a choice between serial and I2C interfaces.


  • I2C display 16x1 AND 16x2, mode selectable
  • User selectable I2C address (BV4542)
  • Software adjustable contrast
  • Software variable back light, variable brightness
  • 79 key buffer
  • 25 way keypad interface
  • Interrupt pins
  • Wide voltage 3.3V to 5V
  • 5V: 10mA BL on, 1.5mA BL off, 280uA sleep * see datasheet
  • 3V3: 4.71mA BL on, 1.3mA BL off, 170uA sleep * see datasheet
  • Only 2 wires for full I/O control
  • Wake from sleep by keypad, i2c or serial


Example of connecting a 20 way or 16 way keypad

The software resource has Arduion, RPi and ESP8266 running micropython examples. These are by no means complete and are provided as examples only.