I have never used the 1-wire sensor, but I have actually used Thermochrons recorders from Dallas Semi, I still have some in equipment, and I have one in my car at the moment :-)
But there are cases where there are too big, or they are in a noisy environment, and a thermistor is more flexible. Another advantage of the thermistor is the low overhead to make a reading. On most ucontrollers, the ADC runs under interrupts, so it does not take much resources to make a reading. It's only if you want to convert the reading in degrees that you have to run a linearization routine. For low precision needs, I just use an 8 bit lookup table. That gives precision better than a degree C around 25 C with very little CPU time. It's plenty for things like thermal protection or temperature compensation. The 18B20 is almost as small as a thermistor, but I do not have code for it. Can't be too hard though. Thanks for the pointer, Didier > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Poul-Henning Kamp > Sent: Saturday, January 24, 2009 1:48 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Any experienced HP 2804A thermometer > users outthere? > > In message <cd547dcff6d34f198af32525fec67...@didierhp>, > "Didier" writes: > > For permanent measurement points, I prefer the Dallas DS18B20 > 1-wire sensors, they interface to a single I/O pin on > anything programmable and gives 1/160C resolution and +/- > .50C precision. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > [email protected] | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by > incompetence. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
