Question: My Voltage is a bit off
Answer: Voltages are stored in the sensor chip as bytes, so a value between 0 and 255.
To get them into a number one must use a calculation, this calculation has to be the exact opposite of the way the board went from voltage to a byte value.
if the board maker does not stick to the exact specification in the sensor chip's datasheet then mbm will be a bit off.
An option you still have it to see if you can select another voltage configuration on the mbm voltage tab, this will effact all your voltage readout and there might be one that matches your board better.
Soundx98 Note: You can check this by changing/opening MBM5 settings - Voltages - and changing the "Voltage Configuration" from my config files default of "ITE8712F Standard 4" to "ITE8712F Standard 2" and watch the 12v line drop dramatically".
If your still out of luck you can make your own voltage configuration, simply open the voltage.ini file with notepad and start reading
how it's calculated example
the sensor chip retuns 106
MBM (and your bios): 106 * 0.016 = 1.694
0.016 has to be the exact opposite of what the resistors do (only if you made the board you know what it has to be exactly)
Since the sensor chip can only hold byte's you can have a situation where the value that goes from the resistors into the sensor chip is 106.49 = 106
even a very little 0.01 "real" voltage diffrence will cause the value in the sensor chip to go from 106 to 107
now with mbm (and your bios) that would mean
107 * 0.016 = 1.71 where it was 1.69
another way to look at it:
[real voltage 1.70384] / 0.016 = 106.49 = 106 in sensor chip * 0.016 = [voltage mbm 1.69]
[real voltage 1.70400] / 0.016 = 106.50 = 107 in sensor chip * 0.016 = [voltage mbm 1.71]
so a 0.0016 voltage change shows a 0.02 voltage change in mbm or any other program.
this also explains those voltage that seem to move or jump a lot
- Alex
Last edited by Alex van Kaam on 09-16-2003 at 06:00 AM
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