Cooling Raspi

requiemmg

Hi,

I have a cooling Problem with mit MagicMirror. I run on raspi 3b+, raspi overheats (Temp> 60°C) and will eventually freeze.

I’ve tried with a fan, which helps, but as the Pi is without a case attached to the back of a frame, it is almost impossible to fix the fan so that it does not touch anything else, so it gets very noisy. There is not much space between wall and back of the frame, so that a standard case will not fit behind it.

Has anyone found a working solution to this, possibly passive cooling? (A normal, small heat sink is not enough, already tried that.

On Amazon, I only found passive cooling cases for model 4, and I wonder if the would fit anyway.

pandeyprakhar00

Hello,

I am also using my mirror with Rpi3b+.
To avoid overheating of pi, a Heat Sink & Fan is enough to maintain temperature below 50 Deg C.

But as you quoted that the pi is without a case you could use cable ties to attach it to your fan just like this guy did !
https://www.instructables.com/id/Simple-Raspberry-Pi-Cooling-Fan/

Secondly, you can also make the fan automatic so that it does not runs forever ! This link below demonstrates how i did it for my own Magic Mirror !
https://www.youtube.com/watch?v=srMnIcQvDn0&t=88s

You could also decrease the speed of fan by decreasing its potential so it does not make any noise.

My mirror works 24 X 7 and it never freezes !
Check my built here : https://www.youtube.com/watch?v=sCetiJk2Qus&t=68s

Fozi

@requiemmg I’m running my RPi 3B+ just with stock heat sinks and the temperature is always at 60-61 C. This temperature is not really worrying, rather normal. What might happen is that it may start throtteling from 1400 MHz to 1200 MHz when it excedd 60C. There have been some changes in Raspbian in the last years where the temperature limit was set from 70 to 60 C for throtteling and then changed back again. What you could do is raise the throtteling temp to 70 with following entry in in /boot/config.txt:

temp_soft_limit=70

But the Pi shouldn’t freeze at any of these temps. When it freezes, then usually when the memory ran up due to a memory leak. There might be some modules around which handle memory allocation a bit sloppy. As a workaround you can setup a cron job to reboot the Pi regulary, e.g. every 6 or 8 hours for example.

requiemmg

Thanks for your hints.
Well, it does freeze at these temperatures. And I already have a cronjob which reboots the pi every 6 hours, does not help. No freezing when cooling with a fan, but far too noisy, so no, doesnt seem to be a memory problem rather than a heating problem, so I do not think that setting up higher throtteling temperatures will do any good.

sdetweil

@requiemmg why too noisy? I never hear the fans on both my pi 3, pi4 and jetson nano on the other side of the room (6 ft away)

requiemmg

AS I have no case, I have no way to fix the fan without touching anything and then it is scratching on the surface or is vibrating. Tried it a lot, always too loud. No idea on how to get it fixed.

sdetweil

@requiemmg buy a case… cheap

pandeyprakhar00

@requiemmg
Try this if it helps to hold the fan !
Try this if it helps !

requiemmg

I have several cases here, that’s not a problem. There is not enough space between frame and wall.

pandeyprakhar00

@requiemmg can you share photograph of the frame ? It would be easy to visualize. ! may be i could be of any help…