[OpenTRV-dev] Mobile phone detector

[Deniz Erbilgin]

Hi All,

Damon has asked me to do a bit of research into using a mobile phone 
detector as a presence sensor for the bus shelters.

The basic idea is an antenna, and an amplifier/filter tuned to the 
appropriate frequency. Additionally we'd need some kind of conditioning 
to get the output into a microcontroller readable format.

Does anyone have any thoughts on how practical this would be for sensing 
whether there are people waiting?

Regards,

Deniz

P.S. A quick google for how the detectors work gave me the following 
results:
http://www.eeweb.com/project/circuit_projects/cell-phone-detector
http://www.electroschematics.com/1035/mobile-bug-detector-sniffer/
http://www.instructables.com/id/Free-Energy-Cellphone-detector-From-Cellphone-An/
http://www.instructables.com/id/VHF-UHF-RF-Sniffer/?ALLSTEPS