Constant Flickering on the ESP32 Boards?

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(John Sahhar) #1

Constant Flickering on the ESP32 Boards?

All of my ESP32 boards do this constant flicker, it’s like one led that runs down the length of the strip and flickers (seemingly random) colors, It’s not too noticable but it’s quite annoying. I’m at the point where I’m still trying to figure out if it’s my code or it’s the hardware I’m using.

I’m using WS2812B, plus NodeMCU ESP32 boards.

(Chris Parton) #2

Hi @John_Sahhar , I’ve been using ESP32 boards (the DoIt V1 variety) successfully without flicker, but I did have flicker initially.

The main cause of flicker in my particular case was that my data wire that connects the ESP32 and the LED strip was sitting too close to my buck converter, which was creating interference.

Ensure you have the latest Arduino IDE and FastLED code. I think the new-and-improved ESP32 support is still being reviewed before being merged into the main branch, so you might want to try https://github.com/samguyer/FastLED if you’re not using it already.

Make sure the ground of your ESP32 and the ground of your LED strip are connected together, make the data wire between the ESP32 and strip as short as practically possible, and ensure all your solder and connections are secure.

Finally, if you’re not level shifting, that could likely be the culprit. Personally, I’ve been able to run ESP32s without needing any level shifting, but it’s a game of chance. If you decide to try level shifting, give the 74HCT245 a go.

And you mentioned you’re figuring out if it’s your code. Can you run something like this (https://gist.github.com/kriegsman/062e10f7f07ba8518af6) without flickering? Keep in mind that one of the rainbow effects actually has a white flicker programmed into it :slight_smile:

Good luck!

(Sam Guyer) #3

Thanks @Chris_Parton ! That is such a nice, succinct summary of how to troubleshoot ESP32 problems. I want to pin this post to the top of the group!

(Chris Parton) #4

I’m flattered @Sam_Guyer , you’re more than welcome to do so (with any edits you want) if you think it’d be useful!

(Yves BAZIN) #5

@Chris_Parton perfect. I would just ask that if you have to have long distance between the ESP32 and the strip you can use Ethernet cables or twisted a ground line with a data line to shield it. I was able to send data up to 4meters away from the esp32 without any flickering

(John Sahhar) #6

@Chris_Parton @Sam_Guyer Thank you guys so much, big thank you to you Sam. It’s rare that something just fixes an annoying problem so perfectly and quickly. I appreciate your effort.