From: Guenter Roeck Date: Wed, 30 Mar 2016 20:59:58 +0000 Subject: Re: [lm-sensors] ncpXXxh103 compensation values? Message-Id: <20160330205958.GA21993@roeck-us.net> List-Id: References: <56FBDCBD.7080802@gmail.com> <56FBF7B1.1030407@gmail.com> In-Reply-To: <56FBF7B1.1030407@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Maxime Jayat Cc: Joseph McNally , Jean Delvare , lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org Hi Maxime, On Wed, Mar 30, 2016 at 05:58:41PM +0200, Maxime Jayat wrote: > I don't think it is wrong to use ncpXXxh103 instead of ncp15xh103, > because the first number refers to the physical size of the thermistor > and should not change its behavior. In fact the datasheet does the same > kind of grouping. >=20 > I was just wondering what was the reason for the discrepancy between the > datasheet and your values. > Indeed the datasheet I linked earlier, at page 15, gives you verbatim > the content of this array and the result of your calculation does not > match it. > It is not _absurdly_ wrong but, at first sight, it seems like there is a > 10 degrees difference at the extremes (but 10 kOhm at 25 C is correct). >=20 Can the two of you sort this out and send me a fixup patch if necessary ? Thanks, Guenter p.s.: Please don't top-post. > Le 30/03/2016 17:09, Joseph McNally a =E9crit : > > Hello Maxime, > >=20 > > This data was calculated for a Murata NCP15XH103XXXXX. > >=20 > > You have illustrated something to me with your question though. When I > > uploaded this patch, I was following the format of the compensation > > tables that are already present in the file. So i used "ncpXXxh103" > > instead of "ncp15xh103". Also, it was my first patch submitted to the > > Linux kernel. So I may have been over thinking some things! With some > > hindsight, I see that the name is misleading. I'm going to have to > > revisit this patch to make it more 'generic' for other thermistors, or > > make it more specific for this particular thermistor. > >=20 > > I hope that answers your questions. Thanks for pointing this out to me. > >=20 > > Regards, > > Joseph > >=20 > > On Wed, Mar 30, 2016 at 3:03 PM, Maxime Jayat > > wrote: > >=20 > > Hello Joseph, > >=20 > > You recently added support for the ncpXXxh103 in > > drivers/hwmon/ntc_thermistor.c with the following array of values: > >=20 > > +static const struct ntc_compensation ncpXXxh103[] =3D { > > + { .temp_c =3D -40, .ohm =3D 247565 }, > > + { .temp_c =3D -35, .ohm =3D 181742 }, > > + { .temp_c =3D -30, .ohm =3D 135128 }, > > + { .temp_c =3D -25, .ohm =3D 101678 }, > > + { .temp_c =3D -20, .ohm =3D 77373 }, > > + { .temp_c =3D -15, .ohm =3D 59504 }, > > + { .temp_c =3D -10, .ohm =3D 46222 }, > > + { .temp_c =3D -5, .ohm =3D 36244 }, > > + { .temp_c =3D 0, .ohm =3D 28674 }, > > + { .temp_c =3D 5, .ohm =3D 22878 }, > > + { .temp_c =3D 10, .ohm =3D 18399 }, > > + { .temp_c =3D 15, .ohm =3D 14910 }, > > + { .temp_c =3D 20, .ohm =3D 12169 }, > > + { .temp_c =3D 25, .ohm =3D 10000 }, > > + { .temp_c =3D 30, .ohm =3D 8271 }, > > + { .temp_c =3D 35, .ohm =3D 6883 }, > > + { .temp_c =3D 40, .ohm =3D 5762 }, > > + { .temp_c =3D 45, .ohm =3D 4851 }, > > + { .temp_c =3D 50, .ohm =3D 4105 }, > > + { .temp_c =3D 55, .ohm =3D 3492 }, > > + { .temp_c =3D 60, .ohm =3D 2985 }, > > + { .temp_c =3D 65, .ohm =3D 2563 }, > > + { .temp_c =3D 70, .ohm =3D 2211 }, > > + { .temp_c =3D 75, .ohm =3D 1915 }, > > + { .temp_c =3D 80, .ohm =3D 1666 }, > > + { .temp_c =3D 85, .ohm =3D 1454 }, > > + { .temp_c =3D 90, .ohm =3D 1275 }, > > + { .temp_c =3D 95, .ohm =3D 1121 }, > > + { .temp_c =3D 100, .ohm =3D 990 }, > > + { .temp_c =3D 105, .ohm =3D 876 }, > > + { .temp_c =3D 110, .ohm =3D 779 }, > > + { .temp_c =3D 115, .ohm =3D 694 }, > > + { .temp_c =3D 120, .ohm =3D 620 }, > > + { .temp_c =3D 125, .ohm =3D 556 }, > > +}; > > + > >=20 > > Where are these taken from? > > Unlike the other thermistors in the file, these values don't seem to > > match anything in the Murata NTC Thermistor Datasheet. > > See: > > http://www.murata.com/~/media/webrenewal/support/library/catalog/pr= oducts/thermistor/ntc/r44e.ashx > >=20 > > -- > > Maxime Jayat > >=20 > >=20 > --=20 > Maxime Jayat _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors