Power on and off with GPIO
myMPDos can be configured to shutdown the Raspberry Pi safely with a press of a button.
Configuration
- Connect a button to pin 5 (GPIO 3 SCL) and pin 6 (Ground).
- We use the internal pull-up resistor and do not need an external one.
# Add the package mygpiod
apk add mygpiod
# Configure GPIO 3 (SCL)
cat > /etc/mygpiod.d/3.in << EOL
event_request = falling
bias = pull-up
debounce = 1000
action_falling = system:/etc/mygpiod.scripts/shutdown.sh
EOL
# Add a script for shutdown
mkdir /etc/mygpiod.scripts
cat > /etc/mygpiod.scripts/shutdown.sh << EOL
#!/bin/sh
doas /usr/bin/saveshutdown.sh
EOL
chmod +x /etc/mygpiod.scripts/shutdown.sh
# Configure doas
echo "permit nopass mygpiod cmd /usr/bin/saveshutdown.sh" >> /etc/doas.d/mygpiod.conf
# Enable and start the mygpiod service
rc-update add mygpiod
service mygpiod start
How it works
Power on
The WAKE_ON_GPIO powers on the the Raspberry Pi if you shorten pin 5 (GPIO 3 SCL) to ground.
Power off
The myGPIOd daemon listens on pin 5 (GPIO 3 SCL) and calls /etc/mygpiod.scripts/shutdown.sh.