Here here are some pictures of the fully assembled device. The strong IR light is quite impressive. It can be only seen by the digital camera (approx. 850 nm wavelength).

To trigger the webcam attached to the RasPi, few lines of Python code are sufficient. The script grabs a single frame from the cam, when GPIO14 input is set to HIGH.

import os
import time
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(17,GPIO.IN)
input = GPIO.input(17)
while True:
  if GPIO.input(17) == GPIO.HIGH:
    os.system("/usr/bin/fswebcam -c /home/pi/programming/fswebcam.conf")
    time.sleep(5.5)
    os.system("mv ./snap.jpg `date +{c7f7cb1468c0d02af358b3ce02b96b7aadc0ce32ccb53258bc8958c0e25c05c4}s`.jpg")

Now I’ve been ready for a test run at the bird feeder. Unfortunately I had only an old cam with 640×480 resolution – time for an upgrade to the RasPi HD cam ….

After a few minutes, some feathered clients showed up in front of the lens of my cam …

I improved the setup by enclosing the breadboard and RasPi into a box of LEGO bricks. The diodes fit nicely into a brick with holes.

… so my next task is to move the circuit to a perma-proto board or PCB.