Oh well, I’ve another bad case of flickering. The funny thing is it only happens after a while (tens of minutes of running). At the start it works without a smallest hitch, but very gradually gets to full-strip flashing corrupted data style. But when it gets there, no restarting works. It literally needs to cool down again.
Have somebody ever had a problem like this?
It’s 840 of WS2813s, Arduino Mega, FastLED 3.1.6, 300W PSU, power injected every two meters, grounds connected…
Though as I have just two 10AWG lines running from the power source from which the injects split off - under full load these get kinda lukewarm, and the voltage across strip drops to around 4.5V - but I wouldn’t think that would cause a bad case of flicker, or would it? Never had a problem running with 0.5V drop before. Other than that I just have no clue what can cause such a gradual deterioration of signal.
Sure sounds like a bad component somewhere. You got a resistor between data pin and strip?
Yep, 330R. Without it, it glitches like hell all the time, so it’s definitely helping. Though I’ve read somewhere that it should be at the strip side of the data cable lead, not near controller - I’ll try to move him to the other end tomorrow.
I’ve also read that I should run the ground from controller along the data, and connect it near strip as well - now it’s all connected together at the PSU terminal. I’ll try that as well, but I feel like I’m getting so close to voodoo magic 
I wonder if there is a bad solder join along the data line on the led strip itself? Some of those strips have resistors between each led as well. I know when I have had them its usually always been a bad or cold solder joint (that i usually made) or resistor along the strip. I would guess the data line , but sure can be power / ground as well.
Time how long it takes to start flicker… change Max brightness and then try again… might be warming the chips at near operating low end and thermal corrupting the data chain timing
It could also be the power supply starting to fail or becoming unstable as it gets hot…
It’s definitely not the supply, that’s the only thing I’m pretty sure is rock solid. Also even when I drop the load to bare minimum when it starts to flicker, it acts the same. Warming chips might be, though they’re not running particularly hot - I’d say 40 Celsius give or take.
Well when it starts to flicker the whole strip does - could a bad joint along the way do it? As the entry join is solid.
If the power wires are getting warm to the touch, I’d definitely increase the size…
Double up the 10AWG piece and see if that solves: under thermal conditions the 4.5V might easily become 4.2V
@Honza_Jedlicka it’s noise due to the static electricity building up. Twist your cable data around a ground cable. This ground should go the the gnd of the strip where your dataline is. If you are using several data lines do that with all of them. This will provide shielding for you data cable. I personnally use Ethernet cable to wire.
If after that you still have noise issue and you are using long strips do also connect the gnd of your power supply the end of the strips directly.
If your controller is further away than 2m for the strip I would suggest to add a 74hc245 to boost the data signalmissing/deleted image from Google+