Had somebody some strange effect  led panel , apa102 ,

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1

Had somebody some strange effect
led panel , apa102 , teensy 3.1 ,280 led … noise , fire etc runs 100% ok .
FastLED.showColor(CRGB::Red); shows only 275 off led in red , rest stays black … last 5 led does not reacted with Fastled .showColor … If use blink i can address does led without any problem ? any Idea ?

2

Sounds like maybe a power problem. What kind of power supply are you using, and how many amps does it provide?
280 LEDs could draw more than 8 amps…

Here’s a test: if you turn them all to CRGB(128,128,128) how many light up? How about CRGB(255,255,255) [warning: these will be BRIGHT!]

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I uses the led at 50% and a pdu off 350 w 5 v

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Hello Hans,
I have two panels. One matrix 24*24 of 576 APA102 in serial) and the other is circular panel with 519 APA102(Divided in two series of 259apa’s&260apa’s). No problems on Arduino Due. Is the problem only with red color?

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I Will dig in to it this evening ,

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ok if you want I can compare same code with my panel

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Hey Hans, What DATA_RATE_MHZ are you using? I just try 576 apa102’s @ 20MHz and I had the same problem as you (the last 10 were flickering. Then I slowed down to 8MHz and no more problem.

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hey Mark , Tried you solution but the same result ; last 5 pixels are black or change to other color .
Power is ok and feeded on start and beginning off my led pannel . All other stuff i’m doing on my matrix is working fine , only those two FastLED.showColor(CRGB::Red); does not work correctly on my teensy 3.1

9

Ok, two more diagnostic questions:

  • are you using FastLED 3.0, or the 3.1 branch? In either case, I’d recommend making sure you have the very latest code; there have been several bug fixes recently.

  • if you measure the voltage at the START of the leds using a voltmeter/multimeter what is it? And very importantly: if you measure the voltage at the END of the leds, what is it?

My theory is that the voltage drops too low at the END of the LEDs. Are you putting power on both the start and end, or just the start?

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Hey all , voltage at the end is 4, 9 v
Teensy 3,1 , 20 MHz and failed 3.0.3 the latest

Fun is when I do the same with filling the led colors one by one , ( loop function ) fast , so no delay between white and a black its works .

The panel flickers as off the speed buth they all work …