Hi all! I have not been able to do much blinky stuff lately,

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(Sam Guyer) #1

Hi all! I have not been able to do much blinky stuff lately, but I did discover a bit more about the flickery problem I’ve been having with my reactive LED table. It seems like the LEDs are very sensitive to heat. Has anyone else seen this problem?

Here’s the setup: I have a surface with about 60 rings of 12 WS2812s all wired together. The data lines are set up so that there are logically three strips that I drive in parallel. Power is injected every 5 or 6 rings (every 60 or 70 pixels) – power does not seem to be a problem (got a beefy power supply and voltage drop is reasonable).

What I had been finding is that after some time, some of the rings would start flashing white occasionally and then freezing up. I spent a lot of time fiddling with the software and the data lines with no success.

Recently, I found that if I blow hot air on the LEDs, the same thing happens. And it doesn’t take a lot of heat to make them freeze up. When they cool down, they are fine again. On possible issue is that the rings are mounted on foam core, which is probably a great insulator, so the heat builds up a lot.

Any thoughts or recommendations?
Thanks!

(Jeremy Spencer) #2

Mount the rings on a sheet of aluminum, if that doesn’t fix it add some fans :wink:

(Sam Guyer) #3

@Jeremy_Spencer Yeah, I might just try that. Gotta be a little careful about shorting things out!

(Jeremy Spencer) #4

@Sam_Guyer Use the 3M double sided tape that’s on the back of most strips. It’s a reasonable conductor of heat and an electrical insulator. You can also get thermal conductive double-sided tape on AliExpress

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20181105232359&SearchText=thermal+conductive+double+side+tape

(Yves BAZIN) #5

@Jeremy_Spencer thank you

(Sam Guyer) #6

@Jeremy_Spencer That looks great! Thanks.

(Gibbedy G) #7

I had a similar issue where a led would fail on my strip after warming up. I found it was a connection solder joint issue in my case. Can you heat the led up to create the fault, then fix it by applying pressure to the led or chip.

My point is it wasn’t a heat issue rather a dodgy led issue.

(Sam Guyer) #8

@Gibbedy_G I should check that out more carefully. It might explain why the setup is so sensitive to heat.