I recently acquired an APA104 based LED strip and am having the worst time trying to control it. I am powering it with a separate 5v power supply since it draws a ton of current. I wired it up and I have tried multiple libraries and example sketches and I can not get it to work. If I use an example sketch that lights up one more LED on the chain at a time, it will work fine for a few LEDs. Then the entire strip will randomly get dimmer for a LED or two and then will continue adding to the chain just fine. After about 50 or so LEDs it will start flashing random colors and this continues throughout the rest of the time. I tried counting how many LEDs in the issues started, but it kept changing. Sometimes it started 5 LED in, sometimes 8, sometimes it was 16. It was not consistent. My first thought was a timing issue, but I have no idea where to start troubleshooting. I don't have a scope, so I can't look at the data it is sending out, unfortunately.
Sounds like a powering issue. But without a wiring diagram it´s all just guessing. Did you connect the grounds together?
What´s a ton of current? 60 mA on full white for each led is normal. So 50 leds draw up to 3 A. Is your power supply able to provide that?
With FastLED I had no trouble driving these chipset.
Helmuth:
Sounds like a powering issue. But without a wiring diagram it´s all just guessing. Did you connect the grounds together?What´s a ton of current? 60 mA on full white for each led is normal. So 50 leds draw up to 3 A. Is your power supply able to provide that?
With FastLED I had no trouble driving these chipset.
There are the 3 wires, 5v is connected to a 5v 2A wall wart power supply, gnd to gnd, and data to the pin on the arduino. So since it is only a 2A power supply, that could very well be the issue. When I get home from school I will hook up an old computer PSU that can provide 32A at 5v, so power should definitely not be an issue anymore. Hopefully that fixes it because FastLED does have support for the APA104. One thing I noticed is that if I connected the gnd of the power supply to the arduino's gnd pin, the LEDs turned off, and I'm assuming it shorted the power supply. That was quite odd but it was late and I was getting cranky about it not working so I didn't think too much of it.
...connected the gnd of the power supply to the arduino's gnd pin...
Yes, it´s essential that you do this.
Helmuth:
Yes, it´s essential that you do this.
I apologize for the delayed response, but the issue was the power supply. After hooking up the computer power supply and measuring current, at full brightness for all 3 colors (white) it was drawing nearly 8 amps! :o Man that's a lot of current. Thank you so much for you help, I am so glad I got these to work. They look absolutely beautiful and vivid! 
You´re welcome. With 8A I strongly recommend to power the strip at both ends.
Hi I've also bought a 5V APA104 RGB LED strip from eBay recently, anyone with arduino codes? Been trying with some adafruit examples, couldn't get them to work. Thanks in advance.!!