Hi, I want to use the standard PC motherboard hardware monitor features (temperature and fan speed) to monitor a board I´ve designed. I need to know how the interfase is; i.e. what electrical signals the motherboard expects.
It is based on the i2c bus, so is quite easy to interface to.
However, if you don't have that, then you need to use a fan tachometer input from a fan connector on the motherboard, and a thermistor input (these are rare now on motherboards) for the temperature. If that's the case, then search on the fan tachometer signal - it's easy but I can't remember the exact details. It's been discussed before.
If you can get away with just monitoring your fan, just use one with a three-wire connector and connect the tachometer wire to a spare fan header on the motherboard.
If you need more info, let us know exactly what motherboard you have.