My fan shim cooling with xhat + fixes to power issue/ reboots on custom images

Hey all.

I’ve seen a few posts regarding cooling on picade with the xhat fitted (I have the new 10" version with PI4B).
Some are very good but people seem to be hesitant. You shouldnt be.

My process was:

Buy an extended header (11mm version):

Buy a fan shim:

Buy a standoff set (I connected two together on each corner):

This standoff set may be better although I’d brought the one above:

Simply pop off the xhat. Put the fan shim on and then use the extended header and standoff set to raise the hight of the hat.
You could use a lower header and use a single standoff screw but I wanted mine to go higher for the best airflow/cooling.

You may find that at the back it will pull down slightly depending on how tight you turn the screws from the top but it works just fine and is stable. You could always use some small plastic spacers under the hat / loosen off the standoff set at the back if you buy the shorter ones.

In my setup I have just secured 3 of the 4 corners of the hat with the standoff set and it is rock solid. This is due to the fan shim corner that gets in the way of the screw. You could always snip the side of the board off if you reallly wanted to secure all 4 corners but there is not much point.

Finally, because the xhat power input is now higher, I had to make the hole on the back of the picade for the power slightly larger above. I used a stanley knife for this and just filled in the new exposed wood with a black sharpie pen. :-)

Anyway. I find pictures are always handy when it comes to this stuff. Hopfully these work:

The picade is as cool as a cucumber under a moderate 2Ghz overclock at all times.
FYI - The fan is always on when the machine is turned on, but very quiet so this isnt an issue for me. Just dont install the shim drivers as I understand it can cause a conflict with the picade hat.

In addition to this. I found some handy things for custom images.
If you find your picade reboots if powered from the HAT on custom images please see my reply in thread: Pihat keeps rebooting picade - #16 by Fazza

If you’d like to get sound working on picade boot splash screens:

Edit the asplashscreen.sh located (usually) in Opt/retropie/supplementary/splashscreen/
Find the line omxplayer --no-osd -o both -b --layer 10000 “$line”
and change it for omxplayer --no-osd -o alsa -b --layer 10000 “$line”

Your line may look different but the ‘both’ to ‘alsa’ change is the important bit just change that.

I hope this helps people googling this topic.

Regards,

Fazza

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Yeah, there are some pin conflicts, not sure if it will cause you issues or not. Might want to test all the buttons and joystick and watch for any weirdness. Some of the buttons are on the same pins used to control the LED on the fan shim.
Fan SHIM at Raspberry Pi GPIO Pinout
Picade X HAT at Raspberry Pi GPIO Pinout

By default with no control software installed the fan will run continuously. The fan control pin is the one to worry about, its used for i2s on the Picade Hat. A ground on that pin will turn the fan off.

Yeah. Although I’ve used it extensively since and no conflicts at all. As you say, as long as the shim drivers are not installed. All buttons work and the fan stays running no matter what, it doesnt stop or appear to slow on any inputs.

Overall I think this is a good way to go. Dont really need dyanmic cooling provided by the shim drivers/software as you cant hear the fan when the unit is closed.

I’d deffo reccomend this mod to picade owners.

I’m of the opinion that a Pi 4B needs cooling, heatsinks or a fan. It can’t overheat but if it throttles to keep the temp down its going to hurt performance. Even more so if its a tight confines with limited air flow.

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Thanks, this is really helpful. I have the same kit with a Pi 4 4Gb, and I’ve just finished assembling everything. I’m waiting on a new SSD before I can continue, but I was concerned about cooling, so I’ve also just bought the fan and parts following your recommendation. Hopefully I’ll be fully operational in the next couple of days!

Out of interest are you powering the screen off the Pi? I’m hoping to power a SATA 3 SSD and the display off the pi but I’m not sure if there will be enough power for both. I intend to run the OS on the SSD and not use the MicoSD card.

Just a FYI post.
The official Pi 4 case fan has a fan control pin / wire that can be connected to ant GPIO you want to use.
Raspberry Pi 4 Case Fan – Pimoroni
A config.txt edit can set it up.
dtoverlay=gpio-fan,gpiopin=18,temp=55000
Just change the gpiopin= to the pin you want to use. That’s the BCM number.
the temp=55000 is on at 55c and off at 45c. You can change that too if you want.

You’ll just have to get creative as to where you mount the fan. I think I’d go with side of case exhausting the hot air. Or on its side blowing across the Pi 4 soc.

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@saltedlolly

No problem!

I cant answer the SSD I’m afraid as I just use a 500GB SSD. - so yeah, I run everything off the PI power, including screen.
Obviously the PI can run some SSDs based on their power requirements. However its worth researching that as the screen…etc will obviously increase the power draw to the point where an SSD may not get the power it needs. Others on the forum may perhaps be able to guide you on this.

Regards,
Fazza

Edit* “I use a 500GB micro SD”

FYI I went for the longer extended Pi standoffs and they fit perfectly. SSD should be here later today.

Update: ok the SSD arrived and it won’t boot - not enough power. It looks like I may have to use a micro SD after all. Very annoying.

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