LED Cyr wheel: WS2811 / WS2812 strip first pixel dying/burning out
I’m having trouble with the WS2811 / WS2812 strip and the first pixel dying or burning out. First off, I thought I ordered the WS2812B strips, which are supposed to be reverse voltage safe. However, I failed to take a close look at the strip I got, and it wasn’t what was in the picture from AliExpress. I have the WS2812 chips. It is too late to try to return it to China, as I took a month off to go on vacation before I came back to the project.
Still, apparently people have the same problem with the WS2812B chips, so there is still an issue. The WS2812B also needs a 5v signal, whereas a 3.3v signal from the Teensy 3.1 works for the older WS2812 chip.
Notes on issues; NeoPixel is AdaFruit’s version of WS2812, and may or may not mean the B chip
AdaFruit “Best Practices“: – Note I did this, using a ~300 Ohm resistor and 100uF cap (may have been too small), and still had one fail. So, research:
AdaFruit: NeoPixel Strip 60 LED burned first pixel problem • adafruit industries • – WS2811B chip
AdaFruit: Neopixel Strip Pixels dying (?) • adafruit industries •
Via OctoWS2811 there are these details on the signal wire WS281X signal quality(wire length, resistors, and grounds. Oh my!) — which tells me I now need a scope to figure out what resistor I actually need to smooth out the signal (so, I just ordered one).
On https://solarbotics.com/download.php?file=2159 I discovered this tidbit:
So, I’m going to give the 1N4148 diode a try. I just picked some up from Radio shack…seems to not affect things, so hopefully I won’t get anymore dead. I tried with and without the “protection” to kill LEDs by shorting and powering wrong bits, but nothing kills them on demand.
If they fail..then I have to kick down some more $ for:
http://www.aliexpress.com/store/product/4m-DC5V-WS2812B-led-pixel-srip-non-waterproof-60pcs-WS2812B-M-with-60pixels-white-PCB-only/701799_935613197.html
I heard Ray Wu is a good seller to buy from. At $190, only a little more expensive than the last set i bought…
UPDATE: Taking a look at the LEDs I bought from AliExpress I see what looks like a 1N4148 diode and resistor every ~20 pixels or so. Whereas the other strips I bought from Sparkfun don’t have such protection. I’ve been using the Sparkfun strips for testing..maybe that is why they are burning out?
