A while ago, when Raspberry Pi systems were hard to find, I bought a cheap ARM based system called an Inovato Quadra to see what it could do. It doesn’t have the GPIO options of the R-Pi, but it has USB, HDMI and Wi-Fi built in. With the optional USB dongle shown it gains faster Wi-Fi and Bluetooth as well.
Ironically, these are now sold out (they are selling them as part of a HamClock bundle rather than standalone). For those who already have one (or, should they become available again), there were a number of cooling designs online that placed large fans under the case, but they made the footprint much larger and much of the air flow from the fans was going to blow up the outsides of the case. So, I went hunting on Amazon for some better cooling options…
I found a 2-pack of 20mm 5V fans on Amazon. These things are the perfect size for the Inovato Quadra, so then I needed a stand to place them in, and the Quadra on top of it. The design could probably be converted to a single piece, but the two part design allowed me to play with options for the fan inserts.
Once I had the stand, the two fans just dropped into the spaces (make sure the air blows upwards so it goes through the Quadra), and the power cords run out the slots in the back of the stand. The Quadra needs to be inserted so the air flows over the heatsinks inside the case which means standing it on one end as shown in the photo.
Since they are 5V fans, I made a simple T-piece for the power cord that allows the original power supply barrel jack to be plugged in on one end, and provides power to a new jack for the board, and both fans. When the system is plugged in and running, the fans will be too.
I haven’t looked inside the Quadra to see if there is a good place to tap into the 5v supply there, but that might be possible too. Using a USB connector would also work as another option (5V fans are much simpler to find power for on a system like this than the 12V ones).
To test, I ran a video re-encode from H.264 to HEVC. Sadly, it doesn’t look like the ffmpeg available with Ambian has support for the Mali GPU in the Quadra’s SoC, but the CPU encoder was able to bump the temperature from around 50℃ when idle, to about 80℃. Well below the critical level of 105℃ shown in the system monitor – and it held that temperature for the entire time the process ran.
Now I have the cooling sorted out, time to use it for some more things. I will say, it is not the fastest SBC I’ve used. From an ssh session it is OK, but the VNC remote desktop (onto a virtual frame buffer as I have no monitor connected) is a little sluggish.