> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt

# Gravity: CH423 I2C 24 Digital IO Expansion Module

**Type:** Product page · **SKU:** DFR0979 · **Brand:** [DFRobot](https://core-electronics.com.au/brands/dfrobot-australia)
**Page:** https://core-electronics.com.au/gravity-ch423-i2c-24-digital-io-expansion-module.html ([markdown](https://core-electronics.com.au/gravity-ch423-i2c-24-digital-io-expansion-module.html.md))

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

## Pricing

- **Price:** $8.60 (inc GST) — $7.82 AUD, exc GST
- **Quantity discounts:** 6+ $7.43 (exc GST) · 12+ $7.12 (exc GST)

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 31 and Sep 02.

## How to buy

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## Description

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.

### Connection Diagram

 ![Gravity: CH423 I2C 24 Digital IO Expansion Module](https://core-electronics.com.au/attachments/localcontent/connection_1133633e266.jpg)###  Features

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

- Driving LED lights
- Driving Dot matrix screen
- Driving Light Cubes
 
###  Specification

- 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°C ~ 80°C
- Size: 45 x 37mm (1.78 x 1.46”)
 
###  Documents

- [Product wiki](https://wiki.dfrobot.com/SKU_DFR0979_Gravity_CH423_I2C_24_Digital_IO_Expansion_Module)
- [Schematics](https://core-electronics.com.au/attachments/localcontent/be4e249c3a43d875f662a274f6a02341_90524460d99.pdf)
- [Dimension](https://core-electronics.com.au/attachments/localcontent/ca1aa3c10ef105be52eb1f1035a77855_6588255bae3.pdf)
 
###  Parts List

- Gravity: CH423 I2C 24 Digital IO Expansion Module x1
- Gravity-4P I2C/UART Sensor cable x1

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/D/F/DFR0979-1.jpg)