On Friday, October 02, 2015 at 5:03 AM, Jan Kandziora j...@gmx.de wrote: ----- (Both the DS2450 and DS18B20 support a 3.3V bus, the DS2450 still needs 5V as supply voltage then, however.) ... > And I've 4.7K resistor from the 1-wire to +5V. > Make it 1kOhms and ***tie it to 3.3V*** instead. ----- I'm on a BBB, with Ubuntu 14.04 and their default OWFS install. When I first set up my test sensors (two DS18B20), I read somewhere that I needed to power the bus with 4.7K from the 3.3V supply. Did not get any readings, until I added a 10K resistor in parallel with the 4.7K, for 3197 ohms. Now I get solid, repeatable readings, but one sensor reads 2 degrees C above what it read in another system with a 5V bus, and the other reads 5C high. (I got distracted by other projects and never resolved how that could happen...) So is your 1K pull-up really the specification for a 3.3V supply? Could it somehow change my temperature readings? Clues much appreciated! Loren
| Loren Amelang | lo...@pacific.net | ------------------------------------------------------------------------------ _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
