Just for the fun off it i bought a Biltema presence controlled LED lamp for 79 SEK ~9$ having in mind that i should be able to use the nice box and interior to build myself a "cheap" motion detector to add to mySensors project.
I started by opening the lid and remove the board. This was a little troublesome as i had to compress the battery connector to get it out of its position, but i managed.
After that i tested different ways of how to fit in the Arduion mini and the RF in to the box. Unfortunatly i could not get it in without making the PIR sensor board smaller. I just cut down the board at the near the GND connector.
After this i had cut off the VCC and the motion output so i had to fix that by soldering wires for VCC and motion output shown below. connected pin1 and 8 fixin the VCC. and solderded the Via hole to the testpoint to fix the motion output from pin 2. Also i needed to cut the track just right of C3 to disable the fotoresistor so that the sensor work also in daylight.
I assembled back the board. Also you will need to replace the LED with a 10k ohm resistor (to reduce the current when activating) and then connect the Arduino sensor input to the R3 right side. This should give an active low trigger pulse.
And then i placed the component as i see that they should fit.
Now comes the next step to wire the R Fboard to the Arduino and then connect the motion output to the input of the Arduino.
There might be some changes needed for setting up the right length of the pulses on the motion detector. I have to investigate which of the R's and C's just right to the detector that does this.
This is as how far i came today.
Hopefully this will be one of those projects i finish.
I will make updates on the progress