Hi All,
I’m installing around 6 meters of 24v RGBW COB leds (82 modules) type: BTF-24V-FCOB-784L-W
Power supply is 24v 10A
Power provided on start and end of the strip.
I measured voltage on all modules of the stripe and all modules has more than 24v.
With 37 modules configured in wled everything works fine as expected.
If I set up all the 82 leds the entire led stripe start going crazy with random color flashing.
If I decrease the brightness to around 30/255 the LEDs starts to works file also on full length.
Data Line is around 4 meters:
I tried with classics i2c level shifter from Amazon
I tried without level shifter directly from esp output and the result is the same.
So basically if you pull a lot of current your data gets corrupted?
Without seeing your setup I can think of two ways this could happen:
Power supply is overloaded and voltage is dropping which is causing glitching.
You’re trying to pull a huge amount of current through the same ground wire as the data line is returning through and the voltage drop is screwing up the data by lifting the strip ground.
Have you measured voltage when it’s faulting? Not sure what you mean by more than 24v, you should measure less.
Additionally you cannot use i2c level shifters with addressable LEDs. If you’re running without a level shifter you will be very susceptible to noise and need to keep the wires short.
I know that i2c level shifters are not ok for addressable LEDs. I’ve ordered 74AHCT125 and I will try with that.
I also tried to connect the esp directly on the stripe led with 10 cm cable and same issue (with and without i2c level shifter).
During the glitching i measured voltage on power supply and across the led stripe and is stable at 24V.
According to the seller should be 21W/meter so 150w and my power supply is 240w.
Later I will try to make others measurements of the total current used.
10m is very unlikely to work without a level shifter.
You should measure less than 24v under load. Getting exactly 24v while pulling 150w many meters would imply a very thick copper cable.
If you’re going to build the level shifter from components, make sure you include the 100nf ceramic decoupling capacitor as close as possible to VCC/GND.
My bet is on a bad power supply or too small of wiring. I would lean to bad power supply. It is likely not providing the current needed or gets wicked noisy at higher loads. I would stick to Mean Well power supplies.
After some tests I changed the cable to a 3mm diameter cable (around 9 awg) and this improved a bit.
What I noticed is that if i inject the power only on the opposite side of the data in LEDs works fine almost to full brightness.
If I connect power also on the same end of data in the LEDs starts to go crazy.
To me this seems to strange because measuring the current is only 1.3A.
I changed 2 power supply: mean well and Siemens sitop but no changes.
I’m still waiting on the level shifter ic.
Until i wait I will try to add an additional power injection in the middle of the strip.
Without a level shifter you have literally millivolts of margin before your signal drops below being detectable, so almost anything you do can shift it from working to not working or not working back to working. If you find some combination that gives you enough signal to noise to get it working reliably, don’t touch it until you get the level shifter installed.