I've a small and sweet Raspberry Pi zero. When I switch on my Raspy zero without a monitor or keyboard or lan, I don't want switch off the pi directly by putting off the soket by the line. Infact this action can compromise the Raspy. You can breaking the kernel, and the system can crashing after that.
I've written a code that put the last pin in standby for a connection between the ground. When I connect the last pin with ground, the code starting. The code is a simple sudo shutdown -h now
Step 1: Create the Code
import RPi.GPIO as GPIO
import time import os
buttonPin = 21
GPIO.setup(buttonPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)
last_state = True
input_state = True
input_state = GPIO.input(buttonPin)
if (not input_state): print("Shutdown")
os.system('sudo shutdown -h now')
Step 2: Connect the Pins
Now is the moment to connect the pin. After the starting of Raspberry Pi, you can connect the last pin to ground.
You can read on screen, the command: sudo shudown-h now and the Raspberry Pi switch off.
Step 3: Modify the Rc.local
Now if you want start automatically the script do you modify the rc.local file. This file start when you switch on the Raspberry Pi
# # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing.
# Print the IP address _IP=$(hostname -I) || true if [ "$_IP" ]; then printf "My IP address is %s\n" "$_IP" fi
python /home/pi/Desktop/shutdown.py &
Step 4: Mounting a Switch Or...
Now you can mount a switch like in photo. I've mounted a tilt switch. When I turn upside down the Raspberry Pi, this switch off.