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Thread: Booster for Fastled

  1. #1

    Booster for Fastled

    Hello all

    I have a Teensy 3.6 outputting Fastled data. Reasonably simple project. 12v RGB strip by the way.

    I need to extend the cable to the leds, and at 3m I am starting to get data issues. I believe it is because the 3.3v output is borderline for the strip IC to deal with.

    I would like to make a simple booster circuit (or preferably buy one) that will bump that 3.3v Fastled data up to 5v.
    But I understand that some of these 3.3v to 5v level shifters don't play well with the data speeds that Fastled uses.

    Anyone have any suggestions or advice? Maybe a suggestion of a suitable level shifter.

    Thank you
    Last edited by SteveCS; 01-18-2023 at 08:35 AM.

  2. #2
    Could I simply put a single sacrificial RGB led in the actual controller box as the first led?
    Am I wrong in thinking that first WS2815 RGB strip individual driver chip will then output a 5v level signal onwards?

    Click image for larger version. 

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    Last edited by SteveCS; 01-18-2023 at 09:09 AM.

  3. #3
    Junior Member
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    Unusual but it should work.

  4. #4
    If the 3.3v signals are reliable to the first LED, then using the first LED as a level shifter should work. I've used a TXB0104 level-shifter chip with APA102 LEDs without any problem. If you don't want to handle SMD chips a break-out board is available such as https://www.adafruit.com/product/1875

  5. #5
    Senior Member
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    Oakland, CA, USA
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    This thread has more information:
    https://forum.pjrc.com/threads/25549...evel-converter

    In summary, the bidirectional shifters are slower. Use the active, unidirectional faster shifters.

  6. #6
    Senior Member
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    Feb 2016
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    Australia
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    Quote Originally Posted by SteveCS View Post
    Hello all

    I have a Teensy 3.6 outputting Fastled data. Reasonably simple project. 12v RGB strip by the way.

    I need to extend the cable to the leds, and at 3m I am starting to get data issues. I believe it is because the 3.3v output is borderline for the strip IC to deal with.

    I would like to make a simple booster circuit (or preferably buy one) that will bump that 3.3v Fastled data up to 5v.
    But I understand that some of these 3.3v to 5v level shifters don't play well with the data speeds that Fastled uses.

    Anyone have any suggestions or advice? Maybe a suggestion of a suitable level shifter.

    Thank you
    Even level shifted I belive you have issues with a signal like this as the distance increases. Something about balanced / unbalanced signals i dunno. The common thing todo is convert the signal to rs485 levels. The aliexpress devices I use cost a few dollars and will give you the level shifting as a bonus.

    https://www.aliexpress.com/item/3284...d=vaWghBXB2NXp

    pjrc I think sell a rs485 breakout which will do the same thing. You feed one device a 0 - 5 (or 0-3.3) volt signal, it does some rs485 magic and sends it to another rs485 device maybe 100m away and that device spits out 0-5v to your smart led. Works fine for 800khz ws2811 leds.

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