range sensor

ocool_15

Member
2004-11-26 3:15 am
sk
I am looking to build a sensor for a garage. I want it to sense if the car is below the door or not. Range of about 10ft no car and ~5Ft car there. I would like single sensor above door. I was thinking either Infra red or proximity sensor and have Leds at the front of garage for status. I think a pulsed emitter (555 timer based) would give me larger range but I'm unsure of how to implement the actual change sensing....

I could place sheet aluminium square on the floor if that would make it easier? I realize its not "audio" but I think it would be easy enough to answer.
 

ocool_15

Member
2004-11-26 3:15 am
sk
I did some testing with the inductor idea using a 555timer for frequency generation up to ~2.5 khz with a transistor on the output with a inductor in series with the base and also parralleling base to ground and can't get it to sense metal objects yet. I will try in a bit with higher frequnecies. I also found thisparts express sensor which would be a much easier alternative but not as diy fun:yuck: