From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Date: Sat, 05 Jul 2008 16:31:45 +0000 Subject: Re: [lm-sensors] [PATCH] hwmon: it87 support for 16-bit fan reading Message-Id: <20080705183145.7936c0c3@hyperion.delvare> List-Id: References: <76366b180802102232o60442894gfca038eb4b6f181d@mail.gmail.com> In-Reply-To: <76366b180802102232o60442894gfca038eb4b6f181d@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: lm-sensors@vger.kernel.org On Sat, 5 Jul 2008 17:49:23 +0200, Bruno Pr=E9mont wrote: > On Sat, 05 July 2008 Jean Delvare wrote: > > On Sat, 5 Jul 2008 16:22:45 +0200, Bruno Pr=E9mont wrote: > > > Raw sensors readings: > > >=20 > > > it8712-isa-0e80 > > > Adapter: ISA adapter > > > in0: +1.17 V (min =3D +0.00 V, max =3D +4.08 V) > > > in1: +0.82 V (min =3D +0.00 V, max =3D +4.08 V) > > > in2: +3.01 V (min =3D +0.00 V, max =3D +4.08 V) > > > in3: +2.93 V (min =3D +0.00 V, max =3D +4.08 V) > > > in4: +1.25 V (min =3D +0.00 V, max =3D +4.08 V) > > > in5: +1.76 V (min =3D +0.00 V, max =3D +4.08 V) > > > in6: +1.60 V (min =3D +0.00 V, max =3D +4.08 V) > > > in7: +2.94 V (min =3D +0.00 V, max =3D +4.08 V) > > > in8: +3.26 V > > > fan1: 3245 RPM (min =3D 0 RPM, div =3D 8) > > > fan2: 1520 RPM (min =3D 0 RPM, div =3D 8) > > > temp1: +20.0=B0C (low =3D -1.0=B0C, high =3D +127.0=B0C) = sensor > > > thermal diode temp2: +48.0=B0C (low =3D -1.0=B0C, hig= h > > > +127.0=B0C) sensor =3D thermal diode temp3: +25.0=B0C (low = > > > -1.0=B0C, high =3D +127.0=B0C) sensor =3D transistor cpu0_vid: +1= .550 V > > >=20 > > > Bios readings: > > >=20 > > > CPU Temp: 33=B0C > > > System temp: 45=B0C > > > CPU FAN: 5769 RPM > > > Sys FAN: 1496 RPM > > >=20 > > > CPU Core: 1.1V > > > +1.2V: 1.168V > > > +3.3V: 3.008V > > > +5V: 4.992V > > > +1.8V: 1.76V > > >=20 > > > Looking at those values there could be: > > > in0 =3D +1.2V > >=20 > > Unlikely. Vcore is almost always in0, and it seems to be the case > > here. +1.2V would rather be in4. > >=20 > > > in2 =3D +3.3V > > > in5 =3D +1.8V > > >=20 > > > For the other voltages which do seem to be wired somehow even tough > > > far less are mentionned in BIOS monitoring section it's hard to > > > tell what they could match... > >=20 > > The IT8712F can only measure voltages up to 4.08V directly. Other > > voltages need scaling resistors. The nominal voltage after scaling is > > typically 3V (3/4 of the full scale). in3 and in7 are almost 3V so > > they are most probably voltages > 4V scaled down. I would guess in3 > > is +5V and in7 maybe 5VSB. Now you have to figure out the scaling > > factor. 4.992/2.93 =3D 1.703. Typical factors for +5V are 1.666 and > > 1.68, the later is the standard for the IT8712F so I'd say that's > > what you have. > >=20 > > in8 is normally the battery voltage, unscaled. > >=20 > > So my guess for the configuration of your board would be: > >=20 > > label in0 "Vcore" > > label in2 "+3.3V" > > label in3 "+5V" > > label in4 "+1.2V" > > label in5 "+1.8V" > > label in7 "5VSB" > > label in8 "Vbat" > >=20 > > compute in3 ((6.8/10)+1)*@ , @/((6.8/10)+1) > > compute in8 ((6.8/10)+1)*@ , @/((6.8/10)+1) > for second compute you were thinking in7 Oops, yes, of course. > Why are the compute lines that complex for just multiplying/dividing > with 1.68? Is this a workaround for floating-point precision issues? No, libsensors deals with decimals just fine. The above is simply matching the physical reality: the voltage is scaled down using resistors of 10 kOhm and 6.8 kOhm. You can write it 1.68 if you prefer, that doesn't make any difference. --=20 Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors