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Sensor for vehicle presence

Former Member

Hello everyone,

 

I am trying to build a small personal project - we have a limited set of parking spots in the underground parking at work and it all works on a first come, first served basis. I am thinking of installing sensors for each parking place and build an app that can tell me how many available parking spaces there are.

 

I am trying to find out what would be the best sensor to use. The easiest way is to install the sensor above each parking spot and I was looking at the an ultrasonic ranger that works between 3 cm and 4 m. Do you think this would be the right sensor to use? What other options are there and what kind of sensors are usually being used in these cases?

 

Thanks,

Cristi Grigore

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  • 0

    Hi, John, didn't know the Packers played in Guatemala.  Or, was that during your stint with the United Fruit Company?  Say no more.

    One can sense the presence of a car with a magnetometer.  One can detect it as a blackbody radiator.  One can use the car to interrupt an energetic beam, one could use ultrasonic range-finding.  It could be massed.  Heck, you could put an accelerometer in the tennis ball hung from a string. . .

     

    I heard that in the seventies a cop took to sensing the LO of car's FM stereos.  By reckoning in the 10.7 MHz superhet offset he could suss what station they were listening to.  All so he could pull over the cool kids.

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  • 0

    Hi, John, didn't know the Packers played in Guatemala.  Or, was that during your stint with the United Fruit Company?  Say no more.

    One can sense the presence of a car with a magnetometer.  One can detect it as a blackbody radiator.  One can use the car to interrupt an energetic beam, one could use ultrasonic range-finding.  It could be massed.  Heck, you could put an accelerometer in the tennis ball hung from a string. . .

     

    I heard that in the seventies a cop took to sensing the LO of car's FM stereos.  By reckoning in the 10.7 MHz superhet offset he could suss what station they were listening to.  All so he could pull over the cool kids.

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  • 0 in reply to D_Hersey

    Hi Don, Yes it is pretty hard to miss a car with whatever sensor your want to use. I mentioned the system in Guatemala as she seemed to be more interested in results than experimenting and building her own especially on a multiple parking bay situation. It stuck in my mind as one doesn't expect high tech in a 3rd world country but there it was and more sophisticated than anything I had seen in the States. Your 70's cop sounds like he should have been fixing TVs instead of stopping kids. I was a cop in the seventies and I built small 12V to 6 and 9 volt regulators for all my fellow officers so they could plug their radios into the cig adapter. The city was too cheap to buy cars with AM/FM radios.

    Sorry Cristi, Don and I like to Jaw a little bit in other peoples threads from time to time.

    John