Hi,
I am a student working on prototyping a motion detection system. The sensor I am using for my initial tests (a Vernier Go!Motion) claims to be ultrasonic, but it emits a clicking noise every time it takes a measurement. Is this characteristic of all ultrasonic rangefinders? I need a silent device.
I’d love to hear any recommendations for a sensor meeting the following (admittedly vague) specs:
- detects human movement at a range of approximately 0.5 - 3 meters
- silent
- under $50
Thanks in advance.
Do you absolutely require a USB interface?
An excellent option in fact the abovementioned PIR sensor, plugged into a Phidgets 8/8/8 digital input then into your USB port. If you want to keep costs down, but don’t mind investing time to do more programming, an Arduino USB is also a valid option, but the Phidgets API is event based and VERY efficient and easy to work with.
I don’t much about the products but parallax (which is promote by robotshop) seemed to be cheap and powerful. I’m sure an expert from robotshop will answer this question soon. Or perhaps phidget :
Motion Sensor $45.00
•Detects changes in infrared radiation which occur when there is movement by a person (or object) which is different in temperature from the surroundings.
•Narrow sensing area.
•The sensor is Ratiometric.
robotshop.us/phidgets-motion-sensor-1.html
but you must use a ‘decoder’ which is not cheap… There could be a better solution. Will wait for an expert’s answer.
Good luck,
Jeff
