Hi,
I'm working on a light up tail project using a pair of the 8x8 neopixel matric boards inside a tail. The tail is made of faux fur and stuffed with poly fil. I have an arduino micro board running them off a piece of protoboard in a case in my pocket, and I'm powering everything off a usb battery with a 2 amp output. The boards run off pin six, gnd, and +5V pins of the micro.
A single board seemed to work well, but having two boards seems to have create a heat issue. After running for about 5 minutes the boards get pretty warm, and it seems like the arduino controller I'm using konks out like it's run out of power.
I'm guessing that the boards are just heating up and the additional resistance is demanding enough power that it's killing the controller off. I'm running at full brightness, so I'm guessing a big thing I could easily do is just turn the brightness down a chunk to help. My concern with that is it may not show well through the fur.
What I'd like to ask is what else I could do besides turning the brightness down to help with the heat? I realize stuffing it inside polyfil filled faux fur is going to cause create some issues I'm just wondering if adding a separate power tap for the second board or some kind of heat sink might help. I'm open to pretty much anything, I'm even looking at trying to grab some peltier coolers to try out just for kicks.
Let me know if you need more info on how I'm putting this all together, I know I'm a bit spastic in describing things.
Thanks
Heat dissipation for 8x8 neopixel matrix
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- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: Heat dissipation for 8x8 neopixel matrix
I don't know. Are you sure you don't have a short someplace?
- adafruit_support_bill
- Posts: 88145
- Joined: Sat Feb 07, 2009 10:11 am
Re: Heat dissipation for 8x8 neopixel matrix
The insulation and lack of air-flow is not working in your favor. But 2 panels is going to be pulling a lot of current through the Micro. I suspect it is overheating the MOSFET that switches between VUSB & VIN. I' suggest splitting your pack output and feeding 5v directly to the panels.
- cyferwolf
- Posts: 16
- Joined: Wed Dec 25, 2013 2:44 pm
Re: Heat dissipation for 8x8 neopixel matrix
Thanks for the replies. I kinda figured all the added insulation was going to be a problem. :)
I'm relatively certain it's not a short, I checked all the connections out pretty, and I'm using some three jst type connectors for everything to keep it tidy and let me switch out cables if they break from the flexing.
I got redid the sketch to run the setbrightness command at 64 before all the animations. That definitely seemed to help. The matrices didn't seem to get nearly so warm, and the whole thing ran for a couple hours at a stretch. So that seemed to solve the issue completely.
I think when I have some more spare time I'll look at making some new cables that allow me to split the power input for each board off as you suggested. Hopefully that will help with the issue and enable me to run it at a bit brighter setting.
Thankfully even at that low brightness the light from the boards is still easily visible through the fur, and the tail was a big hit with my friends. Can't wait to take it to a con dance and really show off. I already have some ideas about other ways to do it.
I'm relatively certain it's not a short, I checked all the connections out pretty, and I'm using some three jst type connectors for everything to keep it tidy and let me switch out cables if they break from the flexing.
I got redid the sketch to run the setbrightness command at 64 before all the animations. That definitely seemed to help. The matrices didn't seem to get nearly so warm, and the whole thing ran for a couple hours at a stretch. So that seemed to solve the issue completely.
I think when I have some more spare time I'll look at making some new cables that allow me to split the power input for each board off as you suggested. Hopefully that will help with the issue and enable me to run it at a bit brighter setting.
Thankfully even at that low brightness the light from the boards is still easily visible through the fur, and the tail was a big hit with my friends. Can't wait to take it to a con dance and really show off. I already have some ideas about other ways to do it.
Please be positive and constructive with your questions and comments.