Hello! I have a Radxa Rock 5C with the Penta Sata Hat that I use with OMV as a low-powered NAS. Recently I bought this HDD Tray which has support for a 120mm fan. The fans I have with me right now are 12V PC fans with 4 Pin PWM connectors. I have a DC 5.5mm barrel to 4 pin PWM adaptor that basically has only 2 cables to power the fan. This works to get the fan spinning but it is at full speed all the time, which is inconvenient from a noise and power perspective, and also just unnecessary to cool the HDDs. I was able to plug 2 more jumper wires inside the 12V DC to 4 Pin PWM adaptor so it has all the pins for the fan to be controlled via PWM.
My problem is: how do I actually use the Rock 5C to send a PWM signal to the fan? Both the SBC and the SATA Hat have fan headers, but they are 2 pin and 5V (I think, the Hat header is labeled as “5V fan” but I can only see the polarity labels on the Rock 5C header). Can I use these headers in any way to control the 4 Pin PWM fan? Is there a better solution (GPIO maybe?)?
Would really appreciate some insight if anybody has tried this before.
