GPIO Expander Bonnet - 16 Additional I/O over I2C
Raspberry Pi Bonnet adding 16 digital I/O pins via I2C. Pins are configurable as outputs (high/low) or inputs with optional internal pull-ups, grouped into two 16-pin connectors with ground.
Raspberry Pi Bonnet adding 16 digital I/O pins via I2C. Pins are configurable as outputs (high/low) or inputs with optional internal pull-ups, grouped into two 16-pin connectors with ground.
Header A exposes eight MCP23017 GPIO pins; the Learn pinouts page says the bottom row numbered 0-7 is the 8 IO pins.
Header B exposes eight MCP23017 GPIO pins; the Learn pinouts page says the bottom row numbered 0-7 is the 8 IO pins.
The Learn pinouts page states the top row of each GPIO header is ground.
On-board STEMMA QT connector for I2C plug-and-play peripherals on the Bonnet.
MCP23017 interrupt output pin exposed on the Bonnet for GPIO change notification.
MCP23017 interrupt output pin exposed on the Bonnet for GPIO change notification.
Jumper selects the expander GPIO logic rail; Learn page states the Bonnet defaults to 5V and can be changed to 3V.
| Pin | Position | Type | Function | Voltage |
|---|---|---|---|---|
| GPA0-GPA7 | signal | Header A exposes eight MCP23017 GPIO pins; the Learn pinouts page says the bottom row numbered 0-7 is the 8 IO pins. | ||
| GPB0-GPB7 | signal | Header B exposes eight MCP23017 GPIO pins; the Learn pinouts page says the bottom row numbered 0-7 is the 8 IO pins. | ||
| GND headers | ground | The Learn pinouts page states the top row of each GPIO header is ground. | ||
| STEMMA QT | signal | On-board STEMMA QT connector for I2C plug-and-play peripherals on the Bonnet. | I2C logic level shifted from Raspberry Pi 3V logic; Bonnet GPIO side defaults to 5V per Learn page. | |
| INTA | signal | MCP23017 interrupt output pin exposed on the Bonnet for GPIO change notification. | ||
| INTB | signal | MCP23017 interrupt output pin exposed on the Bonnet for GPIO change notification. | ||
| 3V/5V jumper | power | Jumper selects the expander GPIO logic rail; Learn page states the Bonnet defaults to 5V and can be changed to 3V. | Default 5V, selectable 3V |
Shield
Confirm the data interface matches your host board.
Module pins: 3V/5V jumper, GND headers, GPA0-GPA7, GPB0-GPB7, STEMMA QT, INTA, INTB. Schematik maps them to your board in the app.
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