I started playing with the first module listed in my previous post:
The module is really as easy to connect as a normal pir sensor. There are small text on the pcb. The top most connection (indicated with a 'o') is the sensor output (3,3v for a high and 0v for a low). The middle connection is ground and the bottom connection is Vcc (3,3 to 20v according to the ebay listing).
My setup was really simple, just a chinduino powered via usb. The sensor connected to +5v, ground and the output to analog pin A0 (I could have used a digital pin).
The first results are really promising. Some characteristics:
- The sensor is omnidirectional.
- Output is high (3,3V) for 30s when movement is detected
- New movement will restart the 30s timer
- 'low' power consumption. Triggered: 1.5mA; Idle: 1.4mA (measured @5v using a normal multimeter)
- The sensor doesn't react to temperature/light fluctuations (unlike most pir sensors)
Some range tests that triggered the output (note that this is probably not the maximum distance, just the stuff I tested):
- 0-4 meter distance (clear line of sight), moving my arm
- 5-8 meter distance (clear line of sight), walking around
- walking around at 5 meter distance with an indoor brick wall between me and the sensor
Stuff that I still need to test:
- Can the sensitivity be tweaked
- How to change the trigger timer to something else than 30s
- Duration test to see if the module is prone to false positives