shutdown-button.md

Shutdown button for donkeycar

🇫🇷 You can read this documentation in french

Installation and usage of the push button to shutdown a donkeycar

⚠️ If you using our raspberry pi image generate by ansible and packer. All software requirements are already installed and configured on your car. You should just follow our electronic shematic to install it

Install requirements :

install Wiring Pi

# apt-get install wiringpi

Create script bash :

Create pin-shutdown.sh file at /root folder

# nano /root/pin-shutdown.sh

In this file you should add those lines :

#!/bin/bash

pin={{ shutdown_pin }}  # pin 18 (internal: 24) on raspi layout
gpio mode "$pin" "in"

while :; do
	gpio wfi "$pin" rising
	d_start="$(date +%s)"
	gpio wfi "$pin" falling
	d_end="$(date +%s)"
	delta=$((d_end - d_start))
	if [ "$delta" -gt "3" ]; then
		break
	fi
done

logger Shutdown button pressed
shutdown -h now

Save the file, afterward make it executable with chmod +x

# chmod +x /root/pin-shutdown.sh

Create systemd service

You must now create a service so that at startup, the script is launched in the background, so that it can detect the push button at any time.

First, we need to create our service file.

# touch /etc/systemd/system/button-shutdown.service

and write in it :

[Unit]
Description=button shutdown service

[Service]
ExecStart=/root/pin-shutdown.sh
Restart=on-failure

[Install]
WantedBy=multi-user.target

Launch service

First, we need to update the systemctl services to add ours:

# systemctl daemon-reload 

Then, we activate the service so that the script is launched at each start:

# systemctl enable button-shutdown.service 

If you do not want to restart your computer, you can start the service now:

# systemctl start button-shutdown.service 

Finally, to make sure your service is running:

# systemctl status button-shutdown.service

Now, you can use the shutdown button, You must maintain pressed 3 seconds the button for shutdown the car