Been playing with my Arduino stuff today. I cooked my Nano with the 12v rail from a power supply (didn't completely take apart my previous project which happened to use 12v instead of 5v for one of the sources, and I managed to pick that one because it was the red wire....)
Anyway. Getting there with my custom air cooling solution.
The case by my least favourite brand ever.
I just have the stuff there in breakout form for diagnostics.
Pretty straight forward wiring and programming (I'd not used any of this before today).
The sensor is nested in the middle CPU fan pointing at the back of the graphics card, conveniently positioned so that it has (I think) the back of the core and the VRMs. Tested it breifly so far on GTA5 benchmark and the temperature tends to lag behind the reported core temperature, but that's understandable- however it responds pretty quickly. The biggest gap was at 60C on the core, I was getting 50C from the sensor pointed at the card.
In the picture above it's idling, the core is showing 41C. The highest temp during the benchmark was 64C.
Pretty pleased with it overall. Currently I've got all 6 chassis fans running at 80% and whilst they're not an intrusive noise, they're not quiet.
I think I've proved already that it will be reliable to build a bit of code into the Ardunio that says "if temperature is less than 40, then set fans to idle (400rpm), else if temperature is more than 40 but less than 50 then set a medium fan profile, else if higher than 60 then set a high fan profile".