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Arduino beginner

Discussion in 'Electronics & Electrics' started by Agg, Jan 7, 2017.

  1. PabloEscobar

    PabloEscobar Member

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    I don't know enough about it to say either way (re: previous discussions about 'black boxes')

    The Datasheet mentions 800KHz, which is below Cat1, Signalling is just single wire between the output of the Arduino, and the input of the first LED on each string. How can I check for Crosstalk?
     
  2. MUTMAN

    MUTMAN Member

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    are you grounding the return of the twisted pairs ?

    if you disconnect both ends of the signal cable and its still happening then it might be RF running down the dc power cable. maybe a fat blaun would help?

    /grasp at straws
     
  3. PabloEscobar

    PabloEscobar Member

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    I'm grabbing any straw I can :). the 5vDC is run down and back a completely different cable. There is no 'return' on the pairs, they are just twisted togther and used a single wire for signalling.
     
  4. ErrorCode62

    ErrorCode62 Member

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  5. PabloEscobar

    PabloEscobar Member

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    Phuc Me, Now when I want to replicate similar behaviour, to make it easier to make a snowflake, I cant have multiple drops from a single signal wire.

    Urge to Kill Rising.
     
  6. MUTMAN

    MUTMAN Member

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    Not sure where youd go next ...
    Sounds like RF though
     
  7. PabloEscobar

    PabloEscobar Member

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    I'm feeling more and more like Mr Bean...

    Can anyone explain whats happening here? (apart from a Fire Hazard :))

    I've got a Bunch of RGB pixels hooked up to an Old Phone Charger for Power, and an NodeMCU for signalling, using ESPixelStick firmware (https://github.com/forkineye/ESPixelStick)

    The white wire is the data wire and the NodeMCU is pushing an "All red" test pattern. All electrical connections are secure.



    When I grab the data wire, everything works, when I let go of the signal wire, we're in flickertown.
     
  8. pantner

    pantner Member

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    What does the actual circuit look like? is there a pull to ground for the signal wire?
     
  9. PabloEscobar

    PabloEscobar Member

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    I'm not sure what you're asking.

    From what I can gather, the ground for the signal wire, is through the common ground? but as I'm just loading the sketch, and don't understand how it works in its entirety. in this instance, both the Arduino, and the LED's are black boxes to me :).

    Replacing the white wire I was grabbing, with a different bit of wire, seems to have resolved the issue though.
     
  10. MUTMAN

    MUTMAN Member

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    change your signal wires to twisted pairs. make one of the pair a ground. should help minimise the interference
     
  11. pantner

    pantner Member

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    This is the sort of thing I meant

    http://www.resistorguide.com/pull-up-resistor_pull-down-resistor/

    It's possible you just had a dodgy wire/join and you picking up the wire completed the circuit.
     

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