no i hav'nt tried that. Would it make any difference? This is what is says from the site where i got it from:
"This is a simple to use motion sensor. Power it up and wait 1-2 seconds for the sensor to get a snapshot of the still room. If anything moves after that period, the 'alarm' pin will go low.
Red wire is power (5 to 12V). Brown wire is GND. Black wire is open collector Alarm.
This unit works great from 5 to 12V (datasheet shows 12V). You can also install a jumper wire past the 5V regulator on board to make this unit work at 3.3V. Sensor uses 1.6mA@3.3V.
The alarm pin is an open collector meaning you will need a pull up resistor on the alarm pin. The open drain setup allows multiple motion sensors to be connected on a single input pin. If any of the motion sensors go off, the input pin will be pulled low.
The connector is slightly odd but has a 0.1" pitch female connector making it compatible with jumper wires and 0.1" male headers."
The pull-up resistor could make bad contact.
If you disconnect the sensor (so the pull-up resistor will keep the signal high) does that stop the messages "motion detected" ? If that doesn't stop it check the resistor.
You need a multimeter to measure the voltages of the sensor. The cheap digital ones are only 4 or 5 euros/dollars on Ebay, and that includes shipping.