Hi!
I’ve successfully set up WLED on an ESP8266, utilizing a logic shifter for a smooth operation with a 24V LED strip. However, when I use a XL6019 module to convert the 24V from the power supply to 5V, so I don’t the need a separate power supply for the ESP8266 the LED strip flickers. On the other hand, connecting the ESP8266 via USB results in flawless operation. How can I convert the 24V to 5V and resolve the flickering?
I would try and run common ground from the converts input to it’s output. If you showed a diagram of how you have everything wired it might help us see an issue.
Interested to know why you settled on an XL6019 converter and if you have a link for what you chose?
Normally those are Buck-Boost converters meant to handle inputs that fluctuate above and below their output voltage. Theoretically it should work for the setup you describe, but I’d have to see better specs.
For your application a basic buck converter capable of 30V input and 5V output is all you need.
@Jinx
I’ve drawn a rudimentary schematic how it’s all connected.
@divsys
I settled on the XL6019 because it was what I have in hand. I tried a LM7805 but it would get pretty hot even with an heatsink and still had an ocasional flicker. I suppose I should try a basic buck converter, any suggestions?
Well, one obvious possible issue is the I2C style levelshifter. Those are known to have issues with addressable LEDs.
As to why it seems to work via USB but not via the BC? I have no idea at this point, and without at lot of measurements and fiddling about (that may lead to the same conclusion) it’s much simpler just to get a proper shifter.
I’d suggest a 74AHCTxxx based device, only a single 5V supply required. That I2C device will likely cause more trouble than it’s worth.
As divsys suggests I as well would start with a correct shifter.
Maybe the 7805 is swinging, because thermal shutdown. 7805 loss about 1-2 watts! It need a small convector 
I like the switcher replacements from 7805, like this: https://www.lcsc.com/product-detail/Power-Modules_YLPTEC-K7805-500R3_C2992390.html
A smart replacement for levelshifter are 2x RS485 transcivers. A 3,3V version, like SP3485 near ESP. ESP board can power this chip too. And a 5V version (SP485) near stripe. The bus line can be incredible long - up to 500 meter 
RS485 will definitely work, just overkill if you don’t need distance.
No need to look for 3V for the TX board as their inputs are TTL rated (2.4V Vin_Hi), so 3.3V is within spec even on a 5V board.
Thank you everyone for your input.
I ended up using a SN74AHCT125 as logic level shifter and a buck converter of 24v to 5v. It is stable and running. The end product isn’t pretty and stuffed in a junction box. In the end it’s impressive how much cheaper it is than buying a controller. For the fun of it I might design a PCB. There are probably many out there…
