Anyone know how to interface with the SMBus under Windows? Linux is awesome, but I am stuck with Windows right now (job stuff).
Eater, If you're not having any joy with those parts, try these guys: RS Components Good luck - keep us posted.
I'm actually using some LM35s with ADC08831s for a little project I'm working on with a Parallax Basic Stamp II. I'm using 4 of the pairs to monitor temps around a 1990 Honda Civic Station Wagon, display them on a LCD, and then control a servo which adjusts the hot/cold control lever. -special [k]
bryan-> i found this http://www.madhacker.org/mbmsensors.htm It seems that a sensor is automaticly detected on the smbus now, we have to learn how to control an output interface, and not an input interface like this one
Bricolo, (or anyone else in the know) That's ok for temps - what about extra fan info? Could the same circuit be modified to read the tach pulses from the fans, and then get it into MBM via the SMBus?
I'm also looking for one you need an ic, that monitors temperatures, but also rotation speeds of some fans I don't know wich one, you must search for it, and it must have a smbus interface the one I'm looking for must also have pwm, for being able to control the fan's speed
Running fans with pwm usually buggers up the speed signal, it needs continuous power. You can fit an integrator ic in to convert the pwm back to linear before feeding the fan. Think I saw a circuit on the Micrel MIC502 pdf.
cant you just lob a capacitor in there to smooth the signal (as in psus)? 69 dudes edit: was 69 dude for approx 1 second
The Winbond solution (on mobos that have fan speed control in BIOS) is a 47uF capacitor (we used to call them condensers when I was a lad ) across the fan, but they run the pwm at high frequency (about 2kHz IIRC). That will give a fairly low ripple DC supply to the fan electronics, as you don't want the capacitor to fully-charge. It does get a bit complex with just a capacitor, as the fan needs to partly-drain it as fast as the pulse-train partly-charges it - and with a switching transistor that can pass high current pulses from a beefy psu that takes some balancing. The integrator circuit I've seen was nothing complex, just an op-amp IIRC.
Myke Predko has a PIC tutorial book. I got mine through Amazon. It has a PCB for making your own "el cheapo" PIC Programmer and includes software and example code. Nick Vess has a cool Mr. Baybus project at vess.com that mentioned it. The book is sitting on my "to do" shelf , but a quick scan of it looked very interesting. Myke has sample chapters and other good info at his site www.myke.com. Cheers, Mike
