After trying to configure lm-sensors on my EPIA V5000 for some time, I found a nice thread in the lm-sensors mailing lists from 2005, with some information on how to compute the voltages from their raw values.

The response email from the thread is here or [http://lists.lm-sensors.org/pipermail/lm-sensors/2005-October/013859.html].

The part that matters most is this:

[lm-sensors] Running lm-sensors on EPIA 5000 with Debian SARGE 2.6
Roger Lucas roger at planbit.co.uk
Thu Oct 13 16:13:48 CEST 2005


I have done some more digging including probing voltages on the Eden 5000
MoBo.

IN0 is connected to the 12v rail using a potential divider from R54/R55.
The scaling factor is 0.1754.

IN1 is connected to the 5v rail using a potential divider from R51/R52.  The
scaling factor is 0.4167.

IN2 is connected to the 2.5v rail using a potential divider from R56/R57.
The scaling factor is 0.833.

IN3 is directly connected to the Vcore rail (1.2v).  The scaling factor is
1.000.

IN4 is unknown

IN5 is connected to the 3.3v rail within the VT8231.  The scaling factor is
0.6296.

After testing with these values I found that they are correct except the scaling factor of IN5. In my case, the correct scaling factor for IN5 is 1.000 as I show below in the sensors3.conf file:

chip "vt8231-*"

        label in0 "+12V"
        label in1 "+5V"
        label in2 "+2.5V"
        label in3 "+1.2Vcore"
        ignore in4
        label in5 "+3.3V"

        label temp1 "MB Temp"
        ignore temp1
        ignore fan1
        ignore fan2

        set in0_min 12.0 * 0.90
        set in0_max 12.0 * 1.10
        set in1_min  5.0 * 0.90
        set in1_max  5.0 * 1.10
        set in2_min  2.5 * 0.90
        set in2_max  2.5 * 1.10
        set in3_min  1.2 * 0.90
        set in3_max  1.2 * 1.10
        set in5_min  3.3 * 0.90
        set in5_max  3.3 * 1.10

        compute in0 ( @ / 0.1754 ), ( @ * 0.1754 )
        compute in1 ( @ / 0.4167 ), ( @ * 0.4167 )
        compute in2 ( @ / 0.8333 ), ( @ * 0.8333 )
        compute in3 ( @ / 1.0000 ), ( @ * 1.0000 )
        #compute in5 ( @ / 0.6296 ), ( @ * 0.6296 )
        compute in5 ( @ / 1.0000 ), ( @ * 1.0000 )

 And the result of running sensors is:

$ sensors
acpitz-virtual-0
Adapter: Virtual device
temp1:       +32.0 C  (crit = +60.0 C)

vt8231-isa-6000
Adapter: ISA adapter
+12V:       +12.08 V  (min =  -0.18 V, max = +14.99 V)
+5V:         +5.03 V  (min =  -0.07 V, max =  +6.31 V)
+2.5V:       +2.48 V  (min =  -0.04 V, max =  +3.16 V)
+1.2Vcore:   +1.22 V  (min =  -0.03 V, max =  +2.63 V)
+3.3V:       +3.28 V  (min =  -0.05 V, max =  +4.18 V)

That's all. I hope this information is helpful!

Published on Friday 2010/09/24, last modified on Thursday 2012/02/23