Do I Need a Level Shifter, or More Power?

  • I have a 251 LED strip of WS2812B, 3 PIN. I have it powered with a 5v, 20a, 100w power supply. I have a RPI4 which is powered via its own USB-C supply. I have data from the LED connected to GPIO18 on the Pi. I have ground from the LED connected to GPIO30 on the pi.


    When I measure voltage out of the PSU its 5.38v output.


    If I read the power at the end of the LED strip when it is not lit, I read 3.5v.


    I cannot get the LED working at all, just the first pixel lights up currently.


    Do I need to install a level shifter? Or do I need to power the other end of the LED? If I do this, do I need more power? The full 5m strip is stated to be 90w, and I am 49 LED short of full.

  • You absolutely should be powering it from both ends. With that said, it should still work, just gradually dimming if only powered from one end. Have you gone through hyperion settings and set the controller type, LED count, etc? If you have, and it's still only lighting up the first LED, I've seen that happen when the first LED has gone bad. That can happen because of shorts, unsecured connections, improper wiring, etc.

  • Yeah. When I first connected the pi wasn't grounded commonly, maybe something got fried. I am running HyperHDR which needs root that was also causing some problems.


    Do I need a second power supply or can I just branch what I have?

  • Do I need to install a level shifter? Or do I need to power the other end of the LED? If I do this, do I need more power? The full 5m strip is stated to be 90w, and I am 49 LED short of full.

    you have enough power, make sure outcome voltage doesn't exceed 5 volts ( 5.3xx is not okay)

    Connect all GND to GND from every possible way.


    second; as D34DC3N73R said, power from both sides. Powerdrop and currentdrop will happen in that lenght when only power from one side.

    so; at the end of the strip solder a second wires and connect these also to GND and +5volts


    sometimes its better to cut the strip, so instead of 250+ leds divide the number and half of them < cut> then power those separately

    when you power them separately then ALSO power from both sides.

    some kind of ledstrip have huge powerdrops and will never be lit if not being powered correctly

  • Ok, I attached the PSU at both ends, and it brightened it up. I have huge color variation though, this is it at 100% white.


    The corners except for the PSU connection are connected via the white L clips, and if I press hard on them it fluctuates the color and flickers. Also if I lower brightness the colors "normalize" but not 100% the same color even at 10% brightness.


    I assume I need to solder as a next step? If I do, can I user 16 AWG stranded wire?


    If measure power at bottom left (top right is both ends of the PSU connection), I am only seeing 2.4v.

  • white L clips, and if I press hard on them it fluctuates the color and flickers


    soldering, >> its the only thing that will resolve that >> current can not flow freely and/or Data/CLK is being interfered by the BAD connection on those YUCH!!! L-strips.


    you can solder the L-strips INSIDE


    I pulled out the PSU to look at it... And I swear I set it to 110v when I got it, 100% sure I did. But it was on 220, and when I switched it back it normalized the colors. Crazyness. Going to turn down voltage now.


    then you are really lucky, i think that PSU only gave half power> if it was other way around on a low PSU to high powergrid then BOOM!! :)

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