I am trying to build a cell phone detector. I found several schematics online, but I liked the one below best because it has an easy output for the Arduino so I can make fancy readouts and what not.
Because I am a noob with no formal training, I figured I’d better measure the output from Pin 6 before hooking it up to my Arduino and frying it. So I set it up on my breadboard and powered it up with my 11.4V battery.
It worked, sort of. About four feet away, I get zero volts on the output pin. When I move it in towards the antenna, the voltage comes up- for about a half second, then it drops off back to zero. The closer I get the phone to the antenna, the higher the voltage- but it still drops off back to zero if the phone doesn’t move. When I move it, the voltage comes back up, but quickly goes down.
Clearly something is draining the signal. What do I need to do to make the voltage constant? I want the voltage to increase the closer the phone is to the antenna and stay there so I can give distance information with the arduino. Any ideas?? Thanks.