MCP23017 IO Expansion Board
16-bit I/O expander for I2C-bus, MCP23017 on board
How to Use
The I2C interface can be directly connected in parallel.
Note that if more than one MCP23017 module is connected in parallel at the same time, the I2C addresses of the modules need to be modified to be different, and up to 8 can be connected at the same time.
Modify the module i2c address method: not connect or short A0, A1, A2, high level when it is not connected, and is low when it is short, the total can be set to 2x2x2 different i2c address.