Ok, so I think I had my first total catastrophic hardware failure last night. I had a setup of just under 100 WS2812 mounted on a total of 10 strips. They ran perfectly when I had them setup on my workbench with my 20a power supply. I even stressed them overnight to weed out any bad pixels (there were 2.) Anyway I measured the current on full white, and I got 3.8A. I then switched over to a 5A power supply that I planned on using for this project permanently and the second I started the leds, they all flashed as if the power supply couldn’t handle the load. Yes it was a cheap power supply, and yes, I realize I shouldn’t have tried it a second time, but I did. Now, I am unable to get any lights to lite up on the whole array no matter where I inject the data, even after trying a cheap testing rf preprogrammed controller. Also, the arduino nano starts up, but I cannot get that to write to a brand new strip when trying to look for failures… Think both the the strips and the nano could have both been impacted by the surge? Should I bother trying to sort out bad strips from the good ones, or just replace them all? Are these strip prone to surge damage? Would the arduino post and not perform its programming properly if it caught a damaging surge?
Will the arduino run the Blink example that comes with the arduino IDE that blinks the onboard LED (not the FastLED Blink example)?
Have you tried a different output pin on the arduino? Maybe only the pin you were using was burnt out (if that’s what happened).
Curious if you were using a resistor on the Data line?
Or a large capacitor across the strip pos/neg connections?
@marmil so I finally got a chance to look at and diagnose my issues. The arduino definitely fried as it couldn’t sync up with the ide to write a new sketch. The leds had various shorted pixels throughout all ten strips. Now, I didn’t have a capacitor on the leds positive and negative terminals. It took me a while to remount and wire up all new leds, but this time I’m going to be wiring in a capacitor just in case of surges. What a pain in the ass this was all because of a faulty power supply.
@marmil and why a resistor on the data line?
Using a resistor on the data line helps reduce signal reflections that can cause data errors. As a secondary bonus it can also act as a bit of protection for your MCU output pin in case something gets shorted. The value would ideally be determined by the wire used, but I normally just use a 470 ohm resistor. I put it on the end of the data line near the strip, but I’ve see the reverse done also so not sure what’s best practice there. Use something in the range of 150-470, or you can even use a variable resistor and experiment with different values if you suspect data errors and want to try to dial in something more appropriate.
The capacitor between the LED strip’s pos/neg connections is used to help buffer large current changes if lots of LEDs are flashing on/off quickly. Use a 1000 uF, 6.3V or higher. I usually use 16V or 25V size.