Motion sensor integration with a Raspberry PI

1. Why ?
• Background
• I am a cloud solutions architect, and work from home....
• I have customized my work space to make it comfortable and productive
• I have done various projects with the raspberry pi, and have a bunch of spare hardware lying around
• I just wanted to do some cool automation in my work space using a raspberry pi
• The end result seems pretty simple, but , as you'll see in the demo... I walk into my work space, and get greeted "Welcome to the study room" !
2. How ?
• Hardware needed
• Raspberry PI model B 
  
• Motion sensor detector
  
• I used the HC-SR501, but you can use whatever you like... I'd bought five of these for $10 about six months ago on amazon.
• 1p-1p connector wires (female to female)
  
• You can buy 40 of these for a $. We just need 3 wires in this experiment.
• USB keyboard
• HDMI cable and monitor
• Normal computer speakers
• Ethernet connectivity to the PI
• Now the fun stuff ..
• Prepare the software load on the PI
• I used the NOOBS build (2.2.0 at the time of the blog), and then installed the  full Raspbian (debian jessie) build on the PI
• Connect your USB keyboard, LAN cable, HDMI cable, Audio out from the Raspberry PI to your peripherals
• Just get your IP address when the PI boots up, and then you can ssh and scp to it... I won't bore you with the minor details
• The default  login is pi/raspberry , and you will have to enable ssh login by either using the "sudo raspi-config" or use the UI to enable ssh logins
• Wire the hardware






• You can review the pin layouts of the sensor and the PI as provided above, and match the three wires i used (red, yellow, black) to get a better understanding.
• Red wire
• Sensor - Power in
• PI - Pin 14 (DC out)
• Yellow Wire
• Sensor - Hi/Lo output (DC out)
• PI- Pin 26 (GPIO 7)
•  Black Wire
• Sensor - Ground
• PI  - Pin 16 (Ground)
• ..
• Program the PI
• scp the mp3 or m4a audio file you want to play when motion is detected. I called mine study-room.m4a and tested out my audio connection to speakers with the following command
• omxplayer -o local study-room.m4a
• Create the following file (e.g. final.py) using vi or scp or whatever tool you like, and run it : "sudo python final.py" 
• import RPi.GPIO as GPIOimport time
  import os
  
  GPIO.setmode(GPIO.BCM)
  PIR_PIN = 7
  GPIO.setup(PIR_PIN, GPIO.IN)
  
  def MOTION(PIR_PIN):
                 print 'Motion Detected!'
                 os.system("omxplayer -local study-room.m4a")
  
  print 'PIR Module Test (CTRL+C to exit)'
  time.sleep(2)
  print 'Ready'
  
  try:
     GPIO.add_event_detect(PIR_PIN, GPIO.RISING, callback=MOTION)
                 while 1:
                     time.sleep(100)
  except KeyboardInterrupt:
                 print ' Quit'
                 GPIO.cleanup()
• Test it out
• Trigger the motion sensor and watch the output on the screen and the audio on the speaker
• Fine tune the motion sensor hardware , if needed
  
•  Complete the setup
• Added a wifi usb adapter and configured it, so that i can remove the wired lan cable
• Added the command sudo python /home/pi/motion-test/final.py & to /etc/rc.local and modified the python code to provide the full path to the .m4a file - os.system("omxplayer -local \/home\/pi\/motion-test\/study-room.m4a")
3. Demo
4. What's next ?
• Amazon Echo Dot integration...
• Add more sensors ......
• Turn on a lamp, if its dark and motion detected....