Hi All,
I am working on my first led project which currently includes 7 LED strips to be controlled with WLED.
After a hard time with flickering, I eventually found a way to make all of the effects work properly but I need to skip the first 4 LEDs of each strip which is unwanted. Is there any known reason for this? I read that one led ca be used as a level shifter but could not find any info about scenarios where multiple LEDs in a row are needed if this is the case.
The current hardware configurations is:
- ESP32 Wroom DevKit
- 5V 60A PSU
- 4 LED strips of 56 pixels WS2812B (LED strips n. 1-2-3-4, 1 segment each)
- 3 LED strips of 116 pixels WS2812B (LED strips n. 5-6-7, 1 segment each)
- 3 level shifters (two additional strips to be added in a next step of the project for which I need a total of 9 high voltage data lines) DAOKAI 10PCS IIC I2C Logic Level Converter 4 canali bidirezionale livello di tensione Modulo 3.3-5V Shifter per Arduino, con cavo : Amazon.it: Commercio, Industria e Scienza
- each strip is connected with unshielded 3 conductor AWG22 cable of 4m / 13feet
- Only one ground, meaning that ESP32 5V and 3.3V (level shifters as well) share the same GND with PSU and LED strips
For practical reasons, the project is currently wired as follows and I am not sure if this might be a cause of the issue:
- LED strip power directly from the PSU, about 60cm / 2’
- 3 wire cable “A” 4m / 13’ : data lines for strips 5-6-7
- 3 wire cable “B” 4m / 13’ : data lines for strips 1-2-3
- 3 wire cable “C” 4m / 13’ : data line for strip 4 and 5V+GND for ESP32
On a next stage each individual led strip will have its own 3 wire cable.
At first I had several flickering issues which I tried to solve based on all the suggestions I found online:
- installing level shifters;
- 47 Ohm resistor on data line at strip connection (only on strip n. 5 to be able to spot differences against the other strips. No difference found in my case);
- 1000uF decoupling capacitor at line strip connection (as above, only on strip n. 5);
- soldering on PCB instead of using breadboard as I suspected some loose connections here and there.
None of these had a visible effects on the issue, although I guess they improve the overall system reliability.
After further investigation on this configuration, I eventually found that the issue can be solved by adjusting the segment mapping in WLED skipping the first 4 LEDs of each strip by excluding them from each segment (not from the LED preferences configuration page where “Skip first LEDs:” is always 0).
Skipping less than 4 LEDs causes flickering on two or more strips on most of effects (those with a higher refresh rate although solid works but not always).
I would like to use the full length of the strip but, most of all, I am really curious about what’s going on in sight of future LED projects.
The current ESP32 pin layout and LED mapping is as follows:
Any clue? Thank you in advance and please let me know if I missed any relevant information!
G