PIR Sensor on the Pi

Today I soldered a PIR sensor to my Pi! Basically, I want it to detect movement and turn on a LCD screen, then turn the screen off again after a minute of no movement. So when I walk into a room, the screen turns on and when I leave, the screen turns off.

Equipment

Solder

First thing, I looked up the pinout for the Raspberry Pi. The below diagram comes from elinux.org.

We care about one of the 5V, ground and GPIO25 pins.

  • Solder the sensor red cable to either 5V.
  • Solder the black cable to ground.
  • End by soldering the yellow line to GPIO25.

Your results should be similar to my picture below.

back

Next, I used this guy’s pir.py script. The script requires the Python library RPi.GPIO. I installed this by downloading the library from here, the direct link is here. To untag or unzip the file I used the following command:

tar -xvf RPi.GPIO-0.5.4.tar.gz

Before installing it, make sure you have python-dev installed.

apt-get install python-dev

With that necessary package, install RPi.GPIO.

cd RPi.GPIO-0.5.4
python setup.py install

Now you can run the pir.py script. I made some slight changes to his code. I didn’t feel the need to call separate scripts to run a single command so I made the following edits.

import subprocess

to

import os

and

def turn_on(): 
    subprocess.call("sh /home/pi/photoframe/monitor_on.sh", shell=True)
def turn_off(): 
    subprocess.call("sh /home/pi/photoframe/monitor_off.sh", shell=True)

this

def turn_on(): 
    os.system("chvt 2")
def turn_off(): 
    os.system("chvt 2")

Run the script and test it out! The sensor will turn off after a minute of no movement and on again once it detects something. I ended by setting my script to run on startup.

2014-01-30 20.33.51

I need to put a picture in the frame to act as background to the pi…

3 thoughts on “PIR Sensor on the Pi

  1. aj saini says:

    can you please help i am lost
    python setup.py install >> after installing

    which file do i edit to make it look similar to your code

    and

    how do i add it to run on start up

    Thank You

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