This Bonnet provides you with a number of options. Let's take a look!

MCP23017 GPIO Expander Chip

The MCP23017 GPIO expander chip converts Python code into pin instructions.

GPIO Expansion Headers

You can solder the included headers onto the Bonnet, or leave them off for a slimmer setup.

  • The top section is GPB0 - header B.
  • The bottom set is GPA0 - header A.
  • The top row of each set of headers is ground.
  • The bottom row, numbered 0-7, is the 8 IO pins.

STEMMA QT Connector

As of October 31, 2023 - We've added an on-board Stemma QT port for easy plug-n-play of I2C sensors and devices. Use this port for connecting your I2C breakouts to the your Raspberry Pi.

Address Select Jumpers

By soldering closed the address select jumpers, you can change the address from 0x20 to 0x27. This allows up to 8 bonnets for 128 total GPIO.

Use the table below to help determine what address results from soldering various pads.

  • Blank= unsoldered (default)
  • X = soldered

Interrupt Pins

The MCP23017 has interrupt capabilities. There are two IRQ pins (INTA and INTB) you can solder a wire to, if you want to have a quick way of telling if any of the GPIO's changed.

3V/5V Jumper

This Bonnet defaults to using 5V. There is a jumper to swap between 3V and 5V. If you want to change it to 3V, you can cut the trace between the top two pads, and solder the bottom two pads.

This guide was first published on Mar 06, 2019. It was last updated on Feb 13, 2024.

This page (Pinouts) was last updated on Nov 02, 2023.

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