[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:
alt text

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