Sanity Check/Parts list

Troubleshooting
#21

Screen Shot 2021-12-07 at 3.10.20 PM

Clues:

  1. The cuttable section is every 3 LEDs. With individually addressable LEDs that have internal drive circuitry, it costs them nothing to have cuttable solder pads between each pixel so they usually do, even for high density 144/M strips.
  2. There’s an IC in addition to the LEDs, this means each LED won’t have it’s own driver, so the one IC must be able to drive 3 RGB LEDs.
  3. The IC has 10 pins only, it would need 9 pins alone just for 3 RGB LEDs driven in parallel, or 6 pins if muxed using some shared pins. It also needs 2 for power, and 4 more for data + clock inputs and outputs. There’s just not enough pins.
  4. In the description:

Q’ty of LED: 60 leds/Meter Available
Q’ty of IC: 20 pixel /Meter

The wording is strange, but the gist here is you get 20 pixels per meter even though there are 60 LEDs per meter.
5. For 12V there’s only so many ways you can efficiently drive LEDs which only need about 2.4-3.4V each.
6. None of the photos demonstrate individual pixel colors beyond every 3 LEDs, though I’ve seen fake photos so I wouldn’t take it alone.

Screen Shot 2021-12-07 at 3.20.15 PM

#22

@wizard two questions about this.

  1. Ignoring the chip, would there be any downsides you can think of to having 3 APA102s in series, if I really wanted zones of 3 and wanted to run 12V? I imagine you have to pick just one of the APA102s to pass on data and clock from, right?
  2. What in the world do you think that “APA 102 external IC” is? I can’t find reference to external APA102 chips anywhere else.
#23

It wouldn’t work to have 3 of the individually addressable 5V APA102’s in series. Their impedance varies by load so the voltage seen across any individual package could be too high or too low, and current would only flow if they were all “on” at the same time (not just data synchronized, but their PWM intervals + phase as well).

I don’t see anything wrong with 3 LEDs per pixel, thats totally fine for many illumination applications. Its like a 20/M strip density, but 3x the brightness.

My guess is that it’s some kind of clone, can’t find anything like that in a quick search.

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#24

So for the strip to actually be individually addressable it has to have one IC chip per Led.
Explains why these strips that came off these wheel ring lights I got on Amazon. Look so crappy in comparison to the Ws2815 I got on there now running the same pattern it’s like night and day.
LED Wheel Lights 15.5" 4 Wheel Set Color Chasing Moving Wireless by App for Cars Trucks https://www.amazon.com/dp/B07QZLR5FW/ref=cm_sw_r_apan_glt_fabc_3QKV7P1C86NSFA7TSNC0?_encoding=UTF8&psc=1

Lesson learned
Twilight

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#25

I purchased on your crowdsupply to support the v3 launch as at the time I didn’t need it right away. so fortunately I shouldn’t encounter the gs2808 issue with the v2. As for the glitching, if it only happens in between patterns and what not, i think that’s something that I can live with, at least for the first iteration of this project. In the future I will hopefully have more time and cash flow to order a product without the test pattern.

Thanks for the in depth explanation. Learning so much about this subject in a short time is a great boon to having picked up this controller. :smiley:

1 Like
#26

Thanks every one for your help. I just let go of around $400 for parts. Wish me luck.