[TUTORIAL]Adding A Dedicated On/off Switch

[retroprogrammer]

Hey guys here is a quick and easy tutorial on installing a dedicated shutdown button for your RaspberryPi for Retropie :)

Parts list:
. Momentary switch
. 2 Male to female wires
. RaspberryPi 3 with Retropie installed
. Necessary connections for RaspberryPi (keyboard, mouse, etc.)

Lets start:
So first solder your male to female wires to your momentary switch, like so:

And then connect to GPIO pins 5 and 6 with your wires with this diagram:

Now go to the terminal by pressing and F4 on your keyboard and type the following:

1)sudo apt-get install update
2)sudo apt-get install python-dev
3)sudo apt-get install python3-dev
4)sudo apt-get install gcc
5)sudo apt-get install python-pip

Next you need to get RPi.GPIO:

6)wget https://pypi.python.org/packages/source/R/RPi.GPIO/RPi.GPIO-0.5.11.tar.gz

Uncompress the packages:

7)sudo tar -zxvf RPi.GPIO-0.5.11.tar.gz

Move into the newly created directory:

8)cd RPi.GPIO-0.5.11

Now install the module by doing:

9)sudo python setup.py install
10)sudo python3 setup.py install

Next we create a directory to hold the scripts:

11)mkdir /home/pi/scripts

call our script shutdown.py (it is written in python). Create and edit the script by doing:

12)sudo nano /home/pi/scripts/shutdown.py

This is the script, paste it in the blank area:

#!/usr/bin/python
import RPi.GPIO as GPIO
import time
import subprocess

# we will use the pin numbering to match the pins on the Pi, instead of the 
# GPIO pin outs (makes it easier to keep track of things)

GPIO.setmode(GPIO.BOARD)  

# use the same pin that is used for the reset button (one button to rule them all!)
GPIO.setup(5, GPIO.IN, pull_up_down = GPIO.PUD_UP)  

oldButtonState1 = True

while True:
    #grab the current button state
    buttonState1 = GPIO.input(5)

Press CRTL X Then Y and restart the pi

Now we configure our script to run at startup,

14)sudo nano /etc/rc.local

And add the following to the file by typing :

sudo python /home/pi/scripts/shutdown.py &

Press CRTL X Then Y

Now the button should work after a reboot, thanks for using this tutorial and make sure to comment :)
@Retroprogrammer

[mitu]

A few observation to your instructions:

• You don't need to install both Python3 and Python2 modules (steps 9 - 10), it's enough to install the modul for the default Python on the system
• I think the RPi.GPIO library is available as a package (python-rpi.gpio) so it should be installable with a simple apt-get install python-rpi.gpio on a Raspbian system.
• The sudo in step 14, for running the script on startup, is not needed, since the commands there are executed as root anyway on start.
• The script you posted seems incomplete, there is no shutdown command attached to the GPIO toggle, so your script will loop ad infinitum and not do anything.
• The script will also consume 1 CPU core 100%, since it will run in a tight loop forever. I find the approach described in http://raspi.tv/2013/how-to-use-interrupts-with-python-on-the-raspberry-pi-and-rpi-gpio-part-3 to be the best, since it's using almost no CPU.
• Most importantly, there is no provisioning for shutting down EmulationStation cleanly, there have been numerous posts here with solutions for how to safely shutdown a RetroPie system, maybe you should incorporate that.

[retroprogrammer]

@mitu Thanks for the observations, I did this with what I knew I will add dome provisions for safer shutdown thanks :)

[Beretta9]

[KlaxMaster]

@retroprogrammer
sudo apt-get update
not
sudo apt-get install update