The clickable and illuminating I2C controlled GPIO exansion board.



An I2C controlled, breadboard friendly GPIO exansion board based on the Texas Instruments PCF8574 with builtin buttons and LED's for prototyping.

  • 2.5V to 6.0V operation
  • Arduino Library
  • 8 Builtin tactile switches
  • 8 Builtin controllable LED's
  • Breadboard friendly
  • All ports broken out onto pin header
  • Based on the popular PCF8574 I2C IC
  • Low Standby-Current Consumption of 10 μA Max
  • Open-Drain Interrupt Output
  • Compatible With Most Microcontrollers
  • Latched Outputs With High-Current Drive
  • Single Maskable output register for all IO ports

Open Hardware

The gpioEXPANDER board is an open source harware project. All schematics, PCB layouts and gerber files are available on GitHub

Built in Switches and LEDs

With 8 built in LEDs and 8 tactile swtiches, each GPIO port can be used as an input or output.

Conntect Buttons to VCC or GND

Connect the inbuilt switches directly to VCC or GND or utilise the breakout pins for your own purpose.

Breadboard Friendly with Vertical or Horizontal Mount

Mount the board anyway you see fit and have the option to connect any port via the provided breakout pins.