Originally shared by jason brader
I am having trouble powering this led strip. What am i doing wrong? I bought the strip from this vendor on aliexpress. SINON-LEDs ws2812 (The strip is a this one: White 5m 60 IP65 - 60leds/m ws2812b type led @ 5 meters.)
I followed the instructions on the adafruit website for the neopixels but i don’t think this is right. I added a 1000 ohm 10v capacitor before the strip. And got a 5v 20 amp led driver for power.
When powering this strip on, only a couple of leds light up and there is nothing being controlled by the arduino (Clone).
Am I missing something?
so i figured out the current direction issue but now the strip is only powering the first 20 leds. how do i get the rest to light up?
What’s the code that you’re using to drive the leds? (Just want to make sure there isn’t something off in there).
Alternatively - It is possible that you may have damaged an led in the chain, and if so, that would effectively keep any leds after that one from lighting up (because they are chained).
i dont think it is damaged…there are other leds that have power after the 20 leds that are receiving the code and lighting correctly.
I am using the pride2015 example as seen here: https://gist.github.com/kriegsman/964de772d64c502760e5
It looks like those lights may be stuck in a random state. Your video doesn’t show leds after the first 20 lighting correctly, all the leds after the first 20 appear to be stuck. If you damaged an led, it wouldn’t prevent power from going through, it but would prevent data from going through, which would keep you from being able to actually set pixel values.
how would i be able to test that?
I don’t know of a good way other than cutting past the 21st or so led and re-wiring.
You could also try running some other programs just to verify that nothing past the 20th led is doing what it should.
i got a suggestion that the timing could possibly be off. i dont really know what this means…
Here’s a terrible potato image of mine: http://i.imgur.com/DXlnz2Y.jpg
Looks like the same problem, control just stops at some point. You need to look at the datasheet for the lightstrip you bought and look for the timing portion. It will specify:
- How long the control pulse has to be total.
- How long the first part is.
- How long the second part is.
- Within the first part and second part, how long it has to stay hi or low in order to indicate hi or low to the onboard chip.
Then, you have to go into the code you’re using, make sure you’ve picked the right options, THEN go into the library and ensure that it is passing the right amount of time hi and lo to the led strip within the right amount of time.
It’s a pain, I had to reconfigure the adafruit neopixel library by adjusting some assembly instructions to ensure it met the timing requirements. The overall window was correct, the hi/lo in the middle was off.
FastlED"s asm for writing WS2812 data is pretty tightly timed/checked (I was hand counting instruction cycle times and delays - as well as staring at a logic probe’s output the entire time) - and has been driving WS2811/WS2812 (as well as a dozen variants) without much in the way of problems. That you are seeing nothing changing past the 20th led doesn’t speak to a timing problem. Timing problems either result in blasts of white, or completely off, or all the leds flickering randomly. They don’t result in a handful of leds being stuck the same color while the rest are all off.
What happens if you try running some of the example programs instead of pride? (This would indicate whether there’s a problem with the code that you’re running or not). You could also try running a sample program from Adafruit’s NeoPixel library (which would be a quick way of figuring out whether it’s a problem with FastLED or the hardware).
would the ide make a difference? 1.0.6 v of arduino
It shouldn’t - though all the development and testing of FastLED is done with Arduino 1.6.5 (from arduino.cc) or later. Errors introduced by the IDE cause timing problems, which would show up as all off, all on, or lots of flickering, like the above.
(That said, you should move to Arduino 1.6.6)
ill try the adafruit library. I tried examples in fastled. I really hope it’s not an issue with the strip being damaged. I bought this power strip from aliexpress and don’t want to deal with a return. I bought this power supply based off the specs on their store. 
You said above “figured out the current direction issue” - how were you wiring things up incorrectly before? Note that mis-wiring/mis-applying power can, depending on the chipset, fry various components (whether it’s applying a power supply’s 5v line directly to data, or swapping power and ground, or applying a higher voltage power supply to something only expecting 5 volts)
i had the direction of the current backwards. all other v+ v- was correct.
there is an arrow printed on the strip and i plugged power in like this ><
i checked the adafruit library samples code and uploaded. still has the same issue.
alright, i started hacking apart the strip and i guess i damaged it. i soldered new connections and now i have a strand of 89 / 20 / and then gotta do more testing to find more leds that are able to be controlled in series. oh well, i guess it’s part of the learning curve. 
maybe i can make a array of leds with this strip and purchase another long strip. what store in aliexpress is reccommended for purchasing led strips?
Yeah - i have so many pieces of dead strip/lines, it’s not even funny. I’ve been doing this for over five years and I still fry LEDs sometimes
I’m a huge fan of Ray Wu - http://www.aliexpress.com/store/701799 - as are many other people in this community.
