The I2C address bits are selectable using the on-board jumpers. The MCP23017 supports up to 8 different I2C addresses so with two MCP23017 devices on each IO Pi you can stack up to 4 IO Pi boards on a single Raspberry Pi giving a maximum of 128 I/O ports.
The IO Pi includes a 5V port that can be isolated from the Raspberry Pi via an isolation jumper so you can use a seperate high current power supply to power the IO Pi reducing the load on the Raspberry Pi. Use of an external supply is recommended if you plan on connecting more than one IO Pi to your Raspberry Pi.
IO Pi Address Configuration and Specification
Input Ratings & Specifications
Maximum input voltage: 5.5V when isolation jumper is removed
Maximum current on each IO pin 25mA
Maximum current on a single I/O Bank (1 MCP23017 device) 125mA
Click to download schematic PDF.
We have python libraries available for this expansion board. You can download all of the libraries from github at:
To download the libraries to your Raspberry Pi type in terminal:
git clone https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git
Find out how to connect LEDs to the IO Pi and how to control them.