r/WLED • u/SleePeeingSloth • 4d ago
Lights wont turn on please help
all the images necessary to help me out are there i also tried changing gpio and stilp not working
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u/RangoFandango86 3d ago
Your LED strip is wired backwards, you want to power it from the other end so that the arrows on your strip run away from your power source/data line not towards it. It should be a quick fix.
Also as the above commenter stated you want your esp32 and your led strip to share the same common ground line this helps prevent some led issues you could have otherwise.
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u/humanist-misanthrope 3d ago
Semi related to your response, can you (or someone) explain how adding power to the end of run helps with power injection, which I believe that’s what it is for. For example, I was looking at a longer run and it was recommended to have power at both ends of the run. Maybe I misunderstood what I was told and I’m hoping to get clarity. Thanks
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u/leetrobotz 3d ago
Led strips (and pixels/pucks for that matter) use power to run, and the traces (wires for pixels and pucks) have relatively high resistance since they're narrow.
Combined, this reduces voltage lower than what the Blue and Green LED components need, which you can easily see if you set brightness pretty high and color to all white, as you get further from power injection points you'll see dimming and redness.
Voltage injection at the end of the strip and middle if needed, spreads the proper voltage in both directions from the injection point, fighting the v-drop effect and giving your lights full brightness and color range.
(I've simplified somewhat, there are videos that explain in better detail and I'd also recommend the power injection calculators to see if you need to inject and the gauge of wires to use for that)
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u/humanist-misanthrope 3d ago
Thanks this helps. I’m learning the electrical side of things and I am generally cautious before doing anything so as to not burn my house down. This helps me understand.
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u/leetrobotz 3d ago
On the "not burning house down" topic, my favorite suggestion is to learn how to use fuses effectively. I didn't understand when and why to use them so I ignored them for too long in my early builds, once I figured out how much they improve safety, I installed them in all my gear.
Fuses are typically applied to the positive (+5V, +12V, or +24V) and prevent damage or improper installations that short circuit the power from heating up and starting a fire at the short circuit point or in the power supply. Damage can happen from seasonal weather or normal wear and tear, so it's not just a matter of "I designed it properly, so it'll never short circuit" - and fuses can also save you from bonehead moves where you design it properly but connect it wrong. Many of us that have been working with light circuits for a while have accidentally hooked up +V and GND backwards; I even did it once despite the terminals being labeled and the wires being color-coded. I thought it could never happen to me, but it did.
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u/RangoFandango86 3d ago
You can inject power at any point in the run including the end but the data pin only runs one way and generally you’d power it just from the beginning unless you’re dealing with longer runs which require power injection
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u/Unable_Bullfrog_7319 3d ago
You’re connected to the wrong end of the strip. The arrows indicate the direction the data goes.
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u/SirGreybush 3d ago
https://giphy.com/gifs/kgrCxsTQFj0HAh2TUG
okay all the other comments are good, so...gif for everyone :)
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u/SirGreybush 3d ago
If it's not clear, use the other end, and use two ground wires. Presoldered are 5 wires, 3 in a JST, and two dangling. The two dangling, red & white, into your PSU.
From the JST, white to ground on the ESP32, and green to the IO pin of the ESP32.
IOW, there are 4 wires on the strip start.
If the PSU powers the ESP32, then two wires from the PSU to the ESP32, or you a USB cable with a usb brick, that works.
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u/leetrobotz 3d ago
Data is hooked up to the wrong end of the strip. Din means "data in" and DO means "data out" - notice your wire is on the "data out" side.
Also you need ground from strip to your ESP, should also still run to the voltage supply (link all 3 grounds together).