2nd SK6812 on ESP32 is lit up randomly

Issues
1

Hi all… I’ve tried to research this, but cannot seem to find the right answer so I’m posting a new issue. Also, I’m a noob at this, learning as I go :).

Here’s what I have successfully running:
ESP32 running WLED version 0.13.0-b6
SK6812’s
Power supplies
No Level shifter
No MIcrophone (yet).

Here’s the configuration:
I have one stretch of 3 SK6812’s (900 led’s in a line). 5v 40 A power supply connected to ESP32 on a breadboard as well as Strip1 Beginning, Strip1 Ending, Strip 2 Beginning and Strip 2 Ending. I have a 20A Power supply connected to Strip 3 beginning and Strip 3 ending. All of this is with 16 Gauge Silicon wire.

The green Data line is connected from ESP32 to the beginning of Strip 1 which then runs all the way down the 900 leds. the first distance is about 9-10". I didn’t need a level shifter since the distance is so short. (that might change tho).

All that works awesome with WLED SR. Colors work, Effects work, all seems rock solid.

with that 900 stretch set, I wanted to start another 900 stretch off of a 2nd output. so ideally I would have two parallel runs of 900 pins (rectangular tray ceiling that perfectly fits a 600-300-600-300 LED runs). The plan was to have the same power configuration with the 2nd pin output running this set of 900 pins in parallel.

That’s when the weirdness starts.

when I connect the first LED run on the 2nd pin (with it’s own 5v 40A power supply), the lights start going bonkers. This data run is about 9-10" also. All leds work but all are spazzing out. That first stretch of 900 is working fine (colors, effects, etc are fine) but the 2nd one is not.

IT seems to be listening to the board tho because as I change effects, the first output keeps up, but the 2nd one seems to change the way it flickers.

Then, when I tell WLED to power off, Stretch 1 turns off, but Stretch 2 has the first 5 lights on as well as three random patches of LED’s turned on random colors.

I’ve checked voltages… 5.5 - 4.5 volts at all injection points. 5v at the board.

Any ideas? Do I need a level shifter? How do I check voltage on the data line (connect volt meter to Data and to ground?)

Thank you!

Breadboard with red and black as power, and the two data lines - the top one is the first 900 leds, and the bottom one is the next set (ignore the microphone board, that’s not connected yet).

PXL_20221008_181009470
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This is the first spool in the 2nd run when WLED is set to off. first few lights are on, and you can see random lights on within the spool.

PXL_20221008_212620045
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2

Have you connected the grounds between all your power supplies?
There must be common ground for all the strips and data.
Do not connect the V+ lines between the supplies, just the ground.

Quick test to see if you might have a software issue, just swap the GPIO pin connections for string 1 & 2, but leave all the software settings the same. Does the strangeness move to the other strip or stay the same?
That should tell you if the issue is with the MCU or the strip connections.

1 Like
3

That’s interesting - had no idea the strips and data should share a ground. Dumb Q of the day: I assume you mean the 12v ground and not the 110 ground? :slight_smile: and if so (12v Ground), should I just splice the black wires all into one nut? is it is simple as that?

I’ll try to switch the pins and see if the problem moves over first, but wanted to understand the grounding mechanics better also.

thanks!

4

Also, I realized the three strips on the first run/pin already had their grounds connected - each strip was connected to the rest with the built in little widgets, and I was injecting power into those extra two wires sticking out. Happy accident I guess?

Am I right to assume that I’m connecting the white ground of the first strip in the 2nd run/pin to that collection as well? The next two strips in that 2nd run will already have the grounds connected so I assume I just need to link up the first connection in each run?

5

I’m talking about DC grounds only NOT AC.
All you should need is a single wire splice from the secondary strip ground to the primary ground.

All the power grounds need to connect together as you’ve done on one set. If that’s wrong, you probably won’t get anything or at best wrong colours. Then you have to tie the MCU data ground in as well, if that’s wrong you typically get wildly strange patterns/colours/effects with little or no control.

6

thank you @divsys !!!

Once I connected the white lead ground at the origin of the two strips, it all started to gel together. I can now use segments and progam the lights as needed!!! thank you thank you thank you!

Next step is to wire the last two strips onto that new stretch and get the whole shebang running!

-Rishi / brownjohnkent