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Neopixels every so often invert colors
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Neopixels every so often invert colors

by figgyb on Thu Jan 17, 2019 11:45 pm

I made an airport weather map similar to this one: https://pplaviationuk.wordpress.com/creating-a-metar-map/
but using MiniPCB neopixels to make them sit flatter. I've use the same quad-level shifter to up the PiZeroW GPIO to 5v and everything seem to be mostly working ok, except maybe once every hour or so the colors on the pixels get lit inverted.

Here is my code: https://github.com/gfbarros/metarmap/blob/master/metar.py

Again, everything works fine, I update the pixels once per minute, but maybe once every hour when they update they light up with the colors mixed up.
I also noticed that sometimes when the pixels update, they flash once or twice after lighting up.
I have also tried auto_write=False mode and get the same problem.

Any ideas?
figgyb
 
Posts: 27
Joined: Wed Mar 17, 2010 5:19 pm

Re: Neopixels every so often invert colors

by oesterle on Fri Jan 18, 2019 1:49 am

Hi, figgyb!

This looks like a fun project.

Can you show sharp pictures of your wiring? (800x600 works well.) Have you connected all your grounds together?

How many pixels are in the string? What power supply are you using, and what is its rated current in amps? What gauge of wire are you using between the pixels? At maximum brightness, RGB NeoPixels can use up to 60mA each.

It's a good idea, especially for runs of more than a few NeoPixels, to use the capacitor and resistor recommended in Basic Connections section of the NeoPixel Überguide. These help protect the pixels from spikes on the data line and brownouts on the power rail.

Cheers,

Eric

oesterle
 
Posts: 607
Joined: Tue Sep 17, 2013 11:32 pm

Re: Neopixels every so often invert colors

by figgyb on Fri Jan 18, 2019 5:11 pm

Hi Eric,

Sorry, I already potted the board so can't get you a picture :( I could re-make the breadboard to show you but it looks exactly like the one on the website.

I have not used the resistor/capacitor, I'll add the cap right away and see if it makes a difference. If not I'll break it down and add the resistor to see if it helps.
I'm using this 5v 10A PS connected right at the middle of the string of LEDs:
https://www.amazon.com/gp/product/B01M0 ... UTF8&psc=1
I'm using 20AWG wire between the LEDs, there are 70 of them.

Thanks!
figgyb
 
Posts: 27
Joined: Wed Mar 17, 2010 5:19 pm

Re: Neopixels every so often invert colors

by figgyb on Sat Jan 19, 2019 9:42 pm

ok, added the cap and will keep an eye on it. Thanks.
figgyb
 
Posts: 27
Joined: Wed Mar 17, 2010 5:19 pm

Please be positive and constructive with your questions and comments.