In my dual system build I have a number of fans. I want to make a fan controller which works independently of either motherboard so irrespective of which system is on, all case fans will operate. There are a number of threads / examples of PWM controllers on tehnet, so this is certainly possible. My BIG problem though is that I have lovely LED fans - specifically Thermaltake Riing LED fans. The LED control on these isn't simply a matter of sending a signal to a 'normal' addressable RGB LED. Instead the fans have microcontrollers on board. A signal is sent from the proprietary Thermaltake 'control box' to these microcontrollers which in turn tell the LED's what colour and mode to operate in. Thermaltake, of course, have refused to provide any information regarding the operation of this system, claiming it as a 'trade secret' (as if other firms don't offer similar products.... ) The matter is discussed here: https://forum.arduino.cc/index.php?topic=366625.0 but evidently without resolution at that time. Even Thermaltake aren't offering a solution as to controlling multiple fans (ie more than 3, which is the maximum capacity per controller). http://community.thermaltake.com/in...ecting-multiple-rgb-riing-12-fans-in-x9-case/ and what's the point of having a control box / boxes inside the case when you'd need to open the case every time you might want to change colour, or set it to colour cycling, or whatever. If anyone has advice on this it would be much appreciated.