A simple breakout module for the MCP23017 (http://www.microchip.com/wwwproducts/en/MCP23017). I designed this to expand the number of GPIO pins for my Raspberry Pi for use on my Boeing 737 Overhead Panel Project.
- In and Out I2C and Power headers, to allow easy daisychaining.
- voltage divider (5V to 3V) for INT signal to be fed back to Raspberry Pi GPIO
- jumpers to set I2C address
- current limiting resistors for each GPIO
- GND pin for each GPIO
- Extra connection pins for each GPIO (useful for matrix connections)
P1 - Connections to Microcontroller.
P2 - Connections to downstream MCP23017.
P3 - I2C address selection.
R3-R18 - Current limiting resistors.
P6 - GND pins
P7 - GPIO pins
(P8-P10) - extra connections for GPIO Pins.