Hardware (FAN) monitor

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.

Hi,

Many motherboards have an SMBUS header - that's what they use for the sensors. If that's what you have, take a look here for some starters:

**broken link removed**
http://www.interfacebus.com/Design_Connector_Smbus.html

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.

FoxyRick.