IRDOT Sensor Issue

Chops Feb 21, 2019

  1. Chops

    Chops TrainBoard Member

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    Video worth a thousand words. One of the sensors isn't lighting up, but I cannot find a loose wire. Any ideas?
     
  2. Tony Burzio

    Tony Burzio TrainBoard Supporter

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    Rotate your table without moving the track and try again. This will tell us if ambient light (infrared from the sun) is making false inputs.
     
  3. Tony Burzio

    Tony Burzio TrainBoard Supporter

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    In the old days we would put developed negative film in front of infrared sensors to screen out false inputs. Finding analog film these days, however...
     
  4. Chops

    Chops TrainBoard Member

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    Thanks Tony, the manufacturer indicated to me that one sensor might be bad, as the LED on light doesn't come on, and that
    an additional chip, which he is sending me, is required to make the circuit board properly pause the train at center rest position.

    I had taken down all the wiring and did it again, but no soap.

    I do have some spare negatives lying about, if need be I'll give that a whirl.
     
  5. Onizukachan

    Onizukachan TrainBoard Member

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    You can use a cellphone camera. They are not shield against IR and it will show up as white light on the screen.
    Also great way to check your television remote has batteries.
     
  6. Chops

    Chops TrainBoard Member

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    So, take a picture of the sensor when it is activated by shadow?
     
  7. Onizukachan

    Onizukachan TrainBoard Member

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    Just look at it on the screen. Start with one transmitter that works, they are ALWAYS broadcasting.
    Once you know you are sending then you can simply monitor the receiver to make sure it is receiving with a dmm.
    I assume you have a transmitter and receiver paired per end?
    Otherwise it won’t work too well in a subway installation with no ambient lighting.
     
  8. Chops

    Chops TrainBoard Member

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    Electronics not my forte, but if I understand you, the "transmitter" is an IRDOT, yes? In that sense, there is a pair at each distal end and one pair set for a stop and go in the center.

    By the "screen," do you mean the cell phone screen?

    The "tunnel" will be a six foot length of PVC tubing, and when thus fashioned, it will be rather dark inside of it. In that sense, the largest amount of ambient light would thus be largely blocked. As the initial test video, above, shows, the three pairs of transmitters, IRDOT's, are installed, in fully ambient light, but not in the glare of direct sunlight, which as you know, in El Paso, is quite intense.
     
  9. Onizukachan

    Onizukachan TrainBoard Member

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    Well, there should be a transmitter and receiver pair x3, otherwise the train has no IR to block, correct?
     
  10. Onizukachan

    Onizukachan TrainBoard Member

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  11. Jimbo20

    Jimbo20 TrainBoard Member

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    Just to clarify, as Onizukachan stated, if you use a cell phone camera to look down from above into the sensors (as per the red arrow) you should see one of each pair is glowing on the cell phone screen...

    irdot.jpg
     

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