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Thread: Teensy 4.1 and WS2811 pixels

  1. #1
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    Teensy 4.1 and WS2811 pixels

    Hello

    i'm a very newbie...but I like the hobby of Holiday lighting.
    I just got a Teensy 4.1 and i'm very anxious to set up about 400 Ws2811 12V strings.
    I also have a 12V 350watt power supply.
    Is it possible to do a simple single line light show with this setup?
    Any assistance in how you do this would be greatly appreciated...what software and other stuff to use?

    Thank you.
    Regards.
    Doug75

  2. #2
    Senior Member PaulStoffregen's Avatar
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    How many LEDs is this? Is this a huge project with 400 long LED strips? Or just 400 LEDs total?

  3. #3
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    Hi Paul,
    Thanks for the quick reply. It's 400 pixels total.
    Can the Teensy 4.1 fit on the Octows2811 adapter?
    It seems longer with 24 pins as compared to 14 pins on the Octows2811.
    Please advise.
    Thanks,
    Regards,
    Doug75

  4. #4
    Senior Member PaulStoffregen's Avatar
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    Quote Originally Posted by Doug75 View Post
    Can the Teensy 4.1 fit on the Octows2811 adapter?
    Yes, but you need to use these longer pins and these sockets (2 of each):

    https://www.pjrc.com/store/header_14x1_d.html

    https://www.pjrc.com/store/socket_14x1.html

    These allow the longer board to mount higher with the 20 extra pins overhanging the output jacks, like this:




    It's 400 pixels total.
    For only 400 pixels, OctoWS2811 might be a bit overkill. It certainly can work, so if you want to go that way or think you might add more pixels in the future, it might be a good path.

    WS2812Serial could also give you good results with just 400 pixels. It's also non-blocking.

    https://github.com/PaulStoffregen/WS2812Serial

  5. #5
    Senior Member+ MichaelMeissner's Avatar
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    Though the problem with both the Octows2811 and the 74AHCT125 used in the Octows2811 is that they are for 5v lights, and the OP said that he/she is using 12v lights. If the 12v lights can be controlled with a 3.3v data pin, then things are simpler. There is likely a variant of the 74AHCT125 that is as fast acting as the 74AHCT125 but it can handle 12v output.

  6. #6
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    Thanks Guys.
    Is it possible to draw a simple circuit with Teensy 4.1, 500 12V WS2811 pixels and 12v
    power supply.
    Will most likel need power injection?
    Thank you.
    Doug75

  7. #7
    Senior Member PaulStoffregen's Avatar
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    Generally speaking, 12V addressable LEDs need normal 5V digital signals. So far we've not been given a link or datasheet or other solid tech info about the particular LEDs being used in this project, so of course any authoritative technical info would override this assumption. But you can generally assume the data wants to be 5V, not 12V.

    The OctoWS2811 adaptor outputs 8 signals, at 5V level. It should work.

    As described on the OctoWS2811 adaptor page, usually the best way to connect the LEDs is with the power supply connected directly to the LED strips with wires as short and direct as reasonably possible. Each OctoWS2811 output is a pair of twisted wires. Most cables have the white-with-color-stripe connected to GND. A quick multimeter check on ohms mode is good, just to make sure that wire really is connected to Teensy's GND pin. Connect the ground wire to the LED strip, so Teensy's GND and the 12 power supply GND meet at or near the LED strip. Connect the signal to the data input. Pay attention to the little arrows or other marking on the strip indicating data direction. Don't make the rookie mistake of connecting data to the wrong end (output) of the strip!

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