This is an IO expansion module based on the MCP23017 port expander chip. The module can expand your microcontroller to offer an additional 16 IOs.
The module can set eight I2C addresses, which means with this module, the microcontroller can connect 8 modules to expand 128 IOs at most. The module solves the insufficient IO ports problem in applications like robots and interactive media.
This module has 2 groups of IO pins, GPIOA and GPIOB. Each group has 8 independent IO interfaces, and each IO interface can be set to input, output, pull-up input (connect to 100KΩ pull-up resistor), interrupt and so on.
The module has 2 interrupt signal pins: IA and IB. IA is used to detect the interruption in the IO interfaces of GPIOA, and IB is used to detect the interruption in the IO interfaces of GPIOB. When one pin of GPIOA or GPIOB interrupts, the corresponding IA or IB will produce a high-level signal.
If you want to acquire the expansion shield in the diagram below, it can be found here
Connection Diagram - Gravity: IO Expansion Shield for Arduino V7.1
- Expand 128 IOs at most (by using multiple modules)
- Multiple IO mode
- Changeable I2C address by dial switch
- Multiple VCC and GND pins
- Compatible with both 3.3V and 5V
- Operating Voltage: 3.3V~5.5V
- I2C Address: 0x20~0x27
- Digital Input/Output: 20Ma
- Signal Interrupt Pin: IA, IB
- Dimension: 44x32mm / 1.73x1.26inch
|3||C||IIC Clock Line|
|4||D||IIC Data Line|
|6||IA||GPIOA Interrupt Detection Pin|
|7||IB||GPIOB Interrupt Detection Pin|
|9||A0/A1/A2||IIC Address Switch|
- 1x Gravity: MCP23017 I2C 16 Digital IO Expansion Module
- 1x Gravity 4-pin I2C/UART Wire