I'm building a lamp using ws2812b as the light source. There are skates every 30th LED, with a total of 240 LEDs. But when I connect the power, only the first 60 LEDs light up. If I go into the settings and change from 240 LEDs to a lower number then 60 LEDs (for example, 5 LEDs), nothing happens. But if I disconnect and reconnect the power, it light up 5 LEDs. Then, when I change the settings back to 240 LEDs while the power is still on, all the LEDs light up now, but if I disconnect and reconnect the power, again only the first 60 LEDs light up.
Does anyone know what the problem could be? I have made several similar lamps in the past, but never encountered this problem before.
Sorry to me skates go on my feet. Post a sketch showing how you have wired it including all power and ground connections. It appears to be a power problem.
Thanks for the response! Hope the sketch is good enough. This is the first time I have made a split (after the 2th led-stripe), may that be the problem? The 60th LED is at the end of the 2th led stripe. I'm using wire-connectors to splice the stripe together.
One problem is that the "split" strings are in parallel. The software can not deal with that. Those two strips will always have the same data and will appear to software as a single strip (they should be identical in length in that case). The last LED in your initial string should be able to drive two LEDs so that is probably not a problem. The other problem is that you do not say how many LEDs in each strip.
I am surprised you are not asking how to replace the regulator. From your schematic you are overloading your UNO 5V. Use an external power supply for the LEDs. Also connect the ends of the strips to the power supply.
Maybe you need to inject power in your WS2812 after LED 60 so it doesn't brown-out the other 200 neopixels? You can power your Arduino AND WS2812 with the same power supply if they both use 5vdc. (BUT never power Neopixels with the Arduino)
(updated - removed lines from uno gnd/5v) ... oops... see post #7
But you need to have the Uno GND connected to the power supply GND !
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This is expected behavior, when the leds are powered, if you send new data to the first 5 leds, that does not change the status of the other leds as long as they are still powered (and sometimes a short power cut does not clear them) . If you want to clear those leds, you should first send data to all 60 leds with color black and then send data to the first led.
that is a little odd. still without the sketch it is hard to say what is the cause of this and of course all of the power related comments should be addressed.
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