You have to connect it and read the ID.
On 06/04/14 23:05, Joris Meijerink wrote: > Hi, > > Anybody here tried to calibrate the 1-wire temperature sensors > additional to the factory calibration? Only reference I've found sofar > is this one: > http://yosemitefoothills.com/Thermometers/ThermometerCalibrations.html > > At the moment I've got 30 DS18B20 measuring inside a glass jar in a > little box of polystyrene foam with water and ice. Connected to a > Raspberry Pi which takes a measurement of all the sensors every 2 > minutes. This takes about 30 seconds. After 8 hours the water is still > pretty cold in a room which is approximately 20°C. Measurements: > http://nl.tinypic.com/r/2mz9wed/8 > > The results are a little spiky. That's probably the resolution of the > sensors? Can this be changed? Or do I have to take an average over 5 > measurements the smooth things a bit? > > When using the average of the 30 sensors as being the "true" > temperature, I can use regression analysis to compensate each sensor. > Sofar i've found that linear regression (-0,04 / +0.06) gives me a > better fit then quadratic regression (-0,14 / +0,25). Probably because > of the small range of the temperature at the moment. > > Linear: http://nl.tinypic.com/r/2u8ur1w/8 > Quad: http://nl.tinypic.com/r/23wpeme/8 > > How can one identify the sensors? Is the id code written on the DS18B20 > itself? Or do I have to plug them in one at the time to ID them? > > Kind regards, > Joris Meijerink > > > ------------------------------------------------------------------------------ > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ Put Bad Developers to Shame Dominate Development with Jenkins Continuous Integration Continuously Automate Build, Test & Deployment Start a new project now. Try Jenkins in the cloud. http://p.sf.net/sfu/13600_Cloudbees_APR _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
