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  • Author Author: sasquatch84
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One Last Thing

sasquatch84

Ok so the unit is working great.  There's just one small thing.  When I was testing different sketches out, I noticed that when the code said "HIGH" it would make the relay pin "LOW" and vice versa.  I tried a few different sketches and uploaded and re-uploaded and it just kept on doing this.  To add More confusion, I tried the classic "Blink" sketch and connected the relay to pin13, but when I did, the LED would light up at the appropriate time, but then when it went low, the output would go high and therefore activate the relay.  Like, totally out of phase with the LED.  So instead of breaking my brain over a problem that might just be explained by this Nano's country of origin (China) I just went back to the original pin I was using and the original sketch and just swapped LOW and HIGH.  Seems to be working great.  I'm still confused, though.

  • I noted in your previous posts, that you were using a 4 channel opto coupled relay board.

     

    The sainsmart and many others tie one end of the optocoupler to Vxx and therefore the input needs to be grounded to energise the relay.

    image

     

    This allows the units to be connected to open collector devices, and work.

     

    If you unit is the same, it would explain why the relay turns ON when the output pin is LOW.

     

     

    Mark

  • Hi Clinton,

    When you have more time draw us another schematic and we will take a look at it. Sometimes, depending how things are hooked up a High output will produce a low in the next step of the circuit. This is called an inverted output. We should be able to get to the bottom and explain what is happening but we will need some more information.

    John