MCP23017_i2c_portexpander

Usage

Determine your i2c device fd by checking available devices in /dev or testing your device with i2cset. Then save your device according to the example params.yaml. Find the device e.g. with this script:

#!/bin/sh
base_path="/dev/i2c-"
for bus in $base_path*; do
	num=${bus#"$base_path"}
	echo "Scanning $bus (num $num)"
	i2cdetect -y -r $num
done

Debugging with i2cset

To test your device beforhands use i2cset. You may want to set 0xff to pin A0. First, set your ports to output

i2cset -r 1 0x20 0x00 0x00

Then set your port to high with

i2cset -r 1 0x20 0x14 0xff

To reset use

i2cset -r 1 0x20 0x14 0x00