These are chat archives for scanlime/fadecandy

4th
May 2016
George Profenza
@orgicus
May 04 2016 10:08
@scanlime I had some issues with some FadeCandies and I've provided details here: https://groups.google.com/forum/#!topic/fadecandy/U9bLwlr-oMU Any hints/tips on what I might be missing/doing wrong ? Thank you
J. Grizzard
@elfchief
May 04 2016 14:02
If that's FB2 frying, that would imply a lot of current flow to ground. What's your physical wiring/setup look like?
J. Grizzard
@elfchief
May 04 2016 15:42
(I guess that's technically "flow across ground")
George Profenza
@orgicus
May 04 2016 15:56
That is the FB2 frying indeed. I've just uploaded some images of the wiring setup. I am now noticing I haven't attached the power supply of the USB hub itself. Could that cause problems ?
J. Grizzard
@elfchief
May 04 2016 16:13
At worst that will just make USB not work. looks at pics You need to tie the grounds of the individual power supplies together, I think. It looks like you've got the power supplies connected to the fadecandies and pixel strings, but not to each other. Connect the output grounds all together. (Don't connect the output 5v together, though). I thiiiiiink that could cause what you're seeing.
George Profenza
@orgicus
May 04 2016 16:14
Thanks @elfchief ! I'll run a test with the grounds connected.
J. Grizzard
@elfchief
May 04 2016 16:16
(The output of the power supplies are all isolated, so unless the grounds are tied together they potentially float at different levels, and then end up equalizing those levels over the only common ground, which is the USB bus).
I'm assuming those fadecandy distribution boards tie power ground and signal ground together? (and/or do you have a schematic?)
George Profenza
@orgicus
May 04 2016 16:18
Regarding the distribution board, I think that is correct and there should be some resistors and a capacitor as per NeoPixel Uberguide best practices (https://learn.adafruit.com/adafruit-neopixel-uberguide/power)
J. Grizzard
@elfchief
May 04 2016 16:27
I boldly run my pixel strings without those capacitors. I am ... brave.
J. Grizzard
@elfchief
May 04 2016 16:34
Also note, for clarity, that the output ground is not the same as the earth/safety ground. ;)
George Profenza
@orgicus
May 04 2016 16:36
Not a whizz with electronics, so I appreciate pointing this out.
J. Grizzard
@elfchief
May 04 2016 16:44
(On my power supplies the output ground is labelled "-5V", I don't know how others are labelled. Can't see the labels on yours. :) But yeah, the one not labelled +5V :)