I'm planning to control about 150 WS2812b LEDs with my Pi Zero and a 5v 11a power source (PC molex connector). Following this guide: https://www.thegeekpub.com/15990/wiring-ws2812b-addressable-leds-to-the-raspbery-pi/ I want to use a logic level shifter (SN74AHCT125N). There's a 400 pin breadboard used in the guide, but I need to use a 170 pin breadboard because of the limited space the controller will be in. Here's a picture of what I'm planning to do, can anyone verify that it will not go up in fire and destroy all my LEDs?

enter image description here

I'm really for the messy sketch, it's my first time using fritzing, I hope everything is clear to understand.

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    \$\begingroup\$ do not use a breadboard in a finished product \$\endgroup\$
    – jsotola
    Commented Jan 27, 2020 at 22:41
  • \$\begingroup\$ For this post, please create a schematic rather than a wiring diagram. For the product, use a sufficiently sized breadboard for development and a proper custom printed circuit board for the finished product. \$\endgroup\$
    – nanofarad
    Commented Jan 27, 2020 at 22:45
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    \$\begingroup\$ Check this question and answer electronics.stackexchange.com/questions/477459/… \$\endgroup\$
    – bobflux
    Commented Jan 27, 2020 at 22:52
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    \$\begingroup\$ DO NOT pass the power and ground for the LED strip through the plastic breadboard - it cannot handle large currents. \$\endgroup\$ Commented Jan 28, 2020 at 6:12

1 Answer 1


It most likely does not burn the LEDs, but it may not work properly either.

There is no bypass capacitor for the 125 chip. Put a 100nF ceramic capacitor directly at its power supply pins, so that there are no extra wires in between. If the waveform still has problems, perhaps a 22 to 33 ohm series resistor at the output helps if the wire to LED strip is long. The AHCT type is capable of high speed operation so it will have very fast transitions at output.

Also the unused gates of the 125 have their data and enable inputs unconnected, connect them to VCC or GND so that all chip inputs do not float.


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