dwl99
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Raspberry Pi 4B, tvhat & fan shim?

Tue Sep 03, 2019 9:00 pm

My Pi4 is idling at 75 degrees which I now know to be pretty normal. I'm looking for advice as to the best way to cool it. It has a tvhat fitted which I guess will limit my options. Does anyone know if the Pimoroni fan shim will fit on the board along with the tvhat? Or is there a better way such as a heat sink?
Thanks

fruitoftheloom
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Re: Raspberry Pi 4B, tvhat & fan shim?

Wed Sep 04, 2019 8:10 am

dwl99 wrote:
Tue Sep 03, 2019 9:00 pm
My Pi4 is idling at 75 degrees which I now know to be pretty normal. I'm looking for advice as to the best way to cool it. It has a tvhat fitted which I guess will limit my options. Does anyone know if the Pimoroni fan shim will fit on the board along with the tvhat? Or is there a better way such as a heat sink?
Thanks

https://shop.pimoroni.com/products/fan-shim

You can use a GPIO Height Extender with the Fan Shim, as per the Pimoroni write up !

https://shop.pimoroni.com/products/booster-header

Though you have to make sure they are not sharing GPIO Pins..
Retired disgracefully.....

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DougieLawson
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Re: Raspberry Pi 4B, tvhat & fan shim?

Wed Sep 04, 2019 8:50 am

They are not sharing pins. The TV HAT uses SPI /dev/spidev0.0 (CS0).
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alphanumeric
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Re: Raspberry Pi 4B, tvhat & fan shim?

Thu Sep 05, 2019 12:41 pm

IMHO a heatsink by itself will not be enough. I have my Pi 4B in a Pimoroni Pibow Coupe case with the matching Pimoroni heatsink. I left my 4B running with a browser window open to one of my camera feeds. Within an hour it creeped up to 80c. Ambient in that room was ~25c. If I turn the floor fan on in that room to get some air circulation it goes back down to ~60c. I have a fan shim on the way. I should have it next week some time to test out.

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PeterO
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Re: Raspberry Pi 4B, tvhat & fan shim?

Thu Sep 05, 2019 1:12 pm

alphanumeric wrote:
Thu Sep 05, 2019 12:41 pm
I have a fan shim on the way. I should have it next week some time to test out.
I have found that a fan-shim (without a heat sink) on Pi4B4 in a coupe case will reach ~62°C when running four cores flat out with a stress test.

PeterO
Discoverer of the PI2 XENON DEATH FLASH!
Interests: C,Python,PIC,Electronics,Ham Radio (G0DZB),1960s British Computers.
"The primary requirement (as we've always seen in your examples) is that the code is readable. " Dougie Lawson

alphanumeric
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Re: Raspberry Pi 4B, tvhat & fan shim?

Thu Sep 05, 2019 1:55 pm

PeterO wrote:
Thu Sep 05, 2019 1:12 pm
alphanumeric wrote:
Thu Sep 05, 2019 12:41 pm
I have a fan shim on the way. I should have it next week some time to test out.
I have found that a fan-shim (without a heat sink) on Pi4B4 in a coupe case will reach ~62°C when running four cores flat out with a stress test.

PeterO
I'm going to try it with and without the heatsink. I have extra thermal pad material to put it back on if I want.

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PeterO
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Re: Raspberry Pi 4B, tvhat & fan shim?

Thu Sep 05, 2019 2:34 pm

Some people have found that adding heat sinks can make things worse because it reduces the air flow over the heat spreader.
Also it depends on the thermal qualities of the pads.

PeterO
Discoverer of the PI2 XENON DEATH FLASH!
Interests: C,Python,PIC,Electronics,Ham Radio (G0DZB),1960s British Computers.
"The primary requirement (as we've always seen in your examples) is that the code is readable. " Dougie Lawson

alphanumeric
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Re: Raspberry Pi 4B, tvhat & fan shim?

Thu Sep 05, 2019 2:48 pm

PeterO wrote:
Thu Sep 05, 2019 2:34 pm
Some people have found that adding heat sinks can make things worse because it reduces the air flow over the heat spreader.
Also it depends on the thermal qualities of the pads.

PeterO
That's why I plan on a with and without test. My thermal tape / pad is 3M 8810

alphanumeric
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Re: Raspberry Pi 4B, tvhat & fan shim?

Fri Sep 13, 2019 8:31 pm

Installed my Fan Shim today. Mounted it on a booster header. Only had to make one small modification to its holder to lower it a little. Cut some plastic away so I could skip using the nuts as spacers.
With the stock software install the fan turns on at 65c and back off again at 55c. Takes about 20 seconds to cool down to 55c. Its a good 20 minutes plus for it to climb back up to 65c, so at this point I'm not going to bother removing the heatsink. I'm happy with how its currently working. :D

MikeDB
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Re: Raspberry Pi 4B, tvhat & fan shim?

Tue Sep 17, 2019 7:02 pm

PeterO wrote:
Thu Sep 05, 2019 2:34 pm
Some people have found that adding heat sinks can make things worse because it reduces the air flow over the heat spreader.
Also it depends on the thermal qualities of the pads.

PeterO
Agreed. Presumably because of the heat spreader on the Pi4, I found the best way is to not use a heat sink. I just use a cheap 5V fan wired in series with two diodes connected to 5V and GND to reduce speed and noise, and even under the heaviest of loads the Pi never goes about 40degC

The fan is on now less than 2 feet from me and I can't hear it at all. Saves all that messing around using up pins and software to turn it on or off as well.
Please write out 100 times "Linux is not a real time operating system so I will not suggest it is"

alphanumeric
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Re: Raspberry Pi 4B, tvhat & fan shim?

Tue Sep 17, 2019 7:11 pm

I stopped and then disabled the service that does the fan control etc of my Fan Shim. The fan just runs continuous now as long as the Pi is powered. My temp hovers right around 40c with the Pi under moderate use. About 35c if its just sitting idle. I'm happy with this setup.
The LED now stays off. The button still works and will shutdown and start up my Pi 4B.

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Pulsar33
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Re: Raspberry Pi 4B, tvhat & fan shim?

Sun Sep 22, 2019 11:40 am

Hello,

@dwl99 : I have a DVB TV pHAT in an official RPI case as you can see below. I had to hack the case in order to connect the antenna and add the fan. I used an official Heat Sink (turned 90° % usual) on which I fixed the 25x25x8 fan. I made a hole in the top case with a wood drill 20mm and added some reused protection. Using a 12vdc fan is more silent and less efficient. You can use a 5vdc fan if needed. Power your fan with GPIO pins +5vdc (J8-4) and Ground (J8-6). Type "pinout" in a shell if needed.

Here is it :
CaseHacking-Fan+DVBreduced.jpg
CaseHacking-Fan+DVBreduced.jpg (242.98 KiB) Viewed 495 times
Best regards
Pulsar33
Pi 4 with 4Gb memory, DVB TV pHAT ------------------- Desktop : Core i5 Linux MINT 19.2

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