Thread Starter


Joined Dec 14, 2007
I need help building a cicuit. I want to place 3 IR sensors at various distances, up to 300 yds away from a control box that will record time and date of a trigger from any of the 3 sensors. I already have control box and 1 sensor ( hardwired ) working. Now i want to use 3 ( remote ) and 1 control box and distinguish which sensor triggered. I was thinking small fm transmitter with 1,2 or3 pulses to determine wich sensor and fm receiver at control box. Does this sound doable (is doable a word?) or is there an easier way?

The control box is a basic stamp with real time clock if thats any help.



Joined Apr 20, 2004
I would use three transmitters on the same frequency, but with a different tone from each sensor modulating the carrier. Use a set of filters at the receive end to determine the sensor.

Here is a link to a transmitter - Substitute an oscillator for the microphone. Be aware that transmitting on an assigned station frequency will attract expensive attention.