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Case for pi3

case
raspberrypi3
Tags: #<Tag:0x00007f1bdf604558> #<Tag:0x00007f1bdf604418>

(Eric Wouters) #1

I know this isn’t really the place but as I know many of you have Pi hardware hanging around I might ask …

I’m looking for a case for a pi3 that will be in my attic. clearly not a ‘cool’ place especially during summer time. I found several with dissipators and ventilators but when I start reading reviews … or not so good or noisy like hell.

Some of you have experience with some cases ? I don’t care color/transparent etc, it has to be efficient as my attic can become really hot and the little PI is running a constant 25% CPU. So I was thinking to add dissipators and a case with ventilator.
Thanks for sharing your experience/ideas


(Bill Thomson) #2

Have you measured the actual temperature in your attic?

I put a wireless thermometer in my attic a couple of years ago, and was very surprised at the results.
For example, as I write this, it’s a cool 52F outside, yet my attic temp is 71F.

During the summer, the attic temperature varies between 110 and 120F. And that’s with my roof painted white!
It was dark green before I painted it, but I didn’t have the thermometer in the attic then, so I don’t know what the temps were.

I checked the roof temp before and after painting. A coat of white paint dropped it 40 degrees, so my guess is the max attic temp was over 120 before the paint job.


(stephen krywenko) #3

probably your summer temp was closer to 150F if it was dark roof on a calm sunny day.


(Eric Wouters) #4

It can be hot in there. No measuring done but the panels producing hot water (glycol exchange system so no steam) can go to 140° C during mid summer … but in a way they take away the heat from attic … but still it will be hot in there.
Why I need to keep th pi as cool as possible and not in a standard case which will accumulate the heat … at least try at best as I have no better place to put the little pi.
And painting the roof isn’t an option …


(Bill Thomson) #5

Wasn’t suggesting you paint your roof. Just pointing out what my temps were with a painted roof. i.e. that they’d be even higher (as Stephen Krywenko pointed out) with an unpainted roof.


(Jon Murphy) #6

I’m not sure what the pi3 is doing but if it runs cool normally (not being in the attic) could you place it on the house side of the insulation (on top of the ceiling but buried under the insulation)? Maybe in a dust proof type box with an IP rating.

Or maybe in a upstairs closet with a some conduit, long cables and fire rated caulk?


(Bill Thomson) #7

Given the steady 25% load he mentioned, putting it under the insulation might have the same effect as running it in an enclosure. (During the summer. Wintertime likely wouldn’t be an issue.)


(Eric Wouters) #8

sorry for the late reply but I’m running a bit everywhere these days.

The pi is basically used to monitor planes (Flightaware) and it is already steadying a bit and cpu usage is rather going around 10% steady, maybe I can optimise it a bit more over time as I learn slowly how that works … but still the attic will become hot this summer. I already thought about putting it elsewhere but roof is pretty high and not easy to access plus it is 30° and slippery. For now the antenna is also in the attic and works pretty nice (I see about 400 km around me this way).
Later I might bring the antenna outside but even then there is no ‘sweet’ spot to install the pi with easy access. I would still bring the antenna cable in and leave the pi in the attic (if it can survive in there) So I was thinking adding 3 dissipators and a fan … At least the heat won’t ‘bild’ up inside the case. Not to sure how hot the cpu can go before it’s security kicks in (think it must be near the 85°C …) Maybe if I can put it as low as possible and center attic I can keep the temp below that level. The roof has isolation …
Next to that I will try to optimize the pi at best so it can go down a few more % cpu usage


(Bill Thomson) #9

The connection from the ADS-B receiver to the Pi is USB, correct?


(Eric Wouters) #10

indeed, and even the dongle is getting pretty hot … wonder if I shouldn’t invent a case to include both …
got the orange one for now, might get me a blue one

dongle


(Bill Thomson) #11

Have you thought of using something like this?

I use one with a Pi that runs MotionPi (camera server app)

It’s an active device, so you should be able to daisy chain two or three of them. That would give you up to 75 feet of cable between the receiver and your Pi.

Low cost too. 7USD each.


(Eric Wouters) #13

didn’t even know that existed … might be an idea … need to drill a hole somewhere to get into a storage room below that is ‘way’ cooler …
let me see if I can find that this side of the ocean
Just need to figure out what the max temp of the dongle is, but will ask that to the ‘inventers’ of it

thanks for the idea Bill


(Bill Thomson) #14

YVW, S!

The search term I used was active USB extension.


(Jon Murphy) #15

Suggestion: from the command line one could monitor the cpu temp °C with (need to divide by 1000):

cat /sys/class/thermal/thermal_zone0/temp

 

A few months ago, when my CPU load was very high, I wrote a node-red flow :
<img src="/uploads/default/original/2X/3/3310124a3cd49384a3ce019479c86d3af5c633a8.png" width=“500” height=>

maybe add a shutdown if the temp get too high.

temp_flow.json.txt (2.9 KB)


(Jon Murphy) #16

I have a active USB extension also - it works very well!

how about an SMA extension cable? https://www.data-alliance.net/sma-extension-cable-25-ft-30-ft-35ft-sma-male-to-sma-female/ ?

This would get all of the electronics out of the attic (include the active USB extension)


(Eric Wouters) #17

as this is a first time test I did last week, I wasn’t to sure how it would work out regarding reception etc. So I followed most common advice to keep dongle close to the antenna … for now there is à 2 m cable. Might play further in 2 weeks, am away coming week end

thanks for all your advice

anf this is the cpu graph

and core temp


(Bill Thomson) #18

ADS-B operates at 1.09 GHz. Keeping the feedline loss to an acceptable minimum (for anything longer than a meter or two) would require using high quality (read that as expensive) coaxial cable. Something like this.

You’re right though, getting all of the electronics out of the heat would be the best option.


(Jon Murphy) #19

Eric - I am assuming you are sending the data to Flight Aware. What info is required from the owner/user of the FlightAware device? Do you enter in longitude and latitude or a home address? or? I am just curious…


(Eric Wouters) #20

you install their soft on your pi, launch it , it phones home with the pi’s mac address and your ip
then you claim it online within your account with flightaware, you get activated and get extra menu’s
once there you add you GPS coordinates (you can choose how precise it will be shown to general public from exact to 10 km near you, so you stay private, except if you’re alone in the middle of the woods) , and that’s it
you get a premium access as reward for participating (+/- 100$/year )

but I found an alternative giving more options on the pi, will test that soon