Gravity: CH423 I2C 24 Digital IO Expansion Module

DFRobotSKU: DFR0979
Sale price £4.08
incl. VAT
excl. VAT
Only 7 units left

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This IO expansion board based on the CH423 chip extends 24 digital ports via I2C, including 8 GPIOs with interrupt functions and 16 GPOs.

CH423 has a built-in current drive circuit that offers a 15mA continuous drive current, which can statically drive 24 LED tubes or dynamically drive 128 LEDs. This CH423 I2C to GPIO IO expander is suitable for projects involving LED tubes, dot matrix screens, light cubes, etc.

Connect Diagram


  • 8 general input/output pins
  • 16 general output pins
  • Built-in driving circuit, up to 15mA continuous driving current


  • Power Supply: 3.3V~5V
  • Static Current: 1mA
  • IO Continuous Driving Current: 15mA
  • Communication: I2C
  • I2C Address: 0x20-0x3F(The module occupies I2C address of 0x20-0x3F and cannot work with I2C device in this address range.)
  • Operating Temperature Range: -20℃~80℃
  • Size: 45*37mm/1.78*1.46”



NO. Silkscreen Description
1 + Power +
2 - Power -
3 SCL I2C clock line
4 SDA I2C data line
5 GPIO Input and output pin
6 GPO Output pin

Pin Mode

Pin Configurable Mode Default
GPO Open-drain output and push-pull output Push-pull output high level
GPIO Input and output Pull-up input

Package Contents

  • 1x Gravity: CH423 I2C 24 Digital IO Expansion Module
  • 1x Gravity-4P I2C/UART Sensor cable

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