2 circuits on one psu causing flickering?

Hello,

I’m trying to set up might lights on my house using strings of WS8211 12v running on ESP8266 node mcu boards with 2 50amp 12v psus. I have injected power at multiple locations in the circuits and when run independently, they work fine but if I try to run 2 circuits on the same power supply, I get flickering in one of the circuits. Has anyone had experience running 2 circuits on the same power supply? Thanks!

What do you mean exactly by 2 circuits?
Are you talking 2 strings driven by 2 MCU boards, or 2 strings driven by 1 MCU board on 2 data pins or 2 strings in series driven by 1 data pin?

Many examples around here, if you do your connections right it should work fine.

2 strings driven by 2 mcu boards connected to the same power supply.

Maybe I should try to run both circuits on one nodemcu? I’ll try to find the docs for doing that.

What is the maximum distance from an MCU to the string(s)?
Are you using any kind of level shifter?
Do both strings flicker or does one depending on which one of the 2 MCU’s you connect or does the same string always flicker?

As far as two strings on one MCU, you can either take the last LED of 1 string and feed it into the 1st LED of the other or create another string in WLED and assign it a new GPIO pin. The usual caveats about distance from the data source (MCU or pixel LED) to the string you’re feeding will apply in either case.

The string that’s flickering is 10” away from the mcu at most. The other string has a sacrificial pixel about 8” away from the mcu followed by about 15’ to the next piexel. No level shifter. The end of one string is very far away from the start of where my second string is so I would prefer to run separate strings.

If I unplug one string, the other works fine with no flicker.

10" should be no issue.
15’ from the level shifter (that’s what the sacrificial pixel effectively does) to the input is getting on the long side. You might have to consider a longer range extender (Tx-Rx RS485 pair ~2$ each) to guarantee clean data.

One other note, you haven’t mentioned how many LED’s you have in each string?
Can one PSU supply enough power for both strings?

The power supply is 600w, definitely capable of handling both strings that are 300+ leds. I ended up hooking them both up to the same nodemcu and it’s working now. The range extenders sound like a good idea. I think i’ll pick up a couple of these anyway. Thanks!

Not sure how you’re powering the nodemcu (typically 5v power), but did you make sure to connect all of the grounds together for your various elements?