Hi Mick, maybe you want to give Stefano's Python-Library for 1wire a try! https://github.com/miccoli/pyownet
It works excellent ;-) Cheers, Martin On 10.03.19 15:57, Mick Sulley wrote: > OK I have now reconfigured my system so that all the I/O modules are > individually powered rather than over the 1- wire cabling, which I am > hoping will improve reliability. Also all sensors are powered. Now > to get back to the other issues. > > How do I set the resolution? Looking at the DS18B20 manual it says > that it is done via the scratchpad, but I have no idea how to do > that. My code is all python, so I guess I can write the necessary > value to the scratchpad at startup, but what do I write? The DS18B20 > manual on GitHub does not mention the scratchpad. > > Thanks > > Mick > > On 19/02/2019 17:38, Jan Kandziora wrote: >> Am 19.02.19 um 14:35 schrieb Mick Sulley: >>> The failure happened for about 10-20 minutes, reading about every 10 >>> seconds or so, then it recovered and is reading fine again. >>> >>> All devices are powered. >>> >>> I could change my code so that it reads fasttemp and if that is 85 it >>> reads through the others to try to find a good read. Is that a >>> sensible >>> thing to do? >>> >> What I recommend to do for preparation is: >> >> * power all sensors >> * set the sensor EEPROM to 9 bit default resolution. >> >> Then, the readout thread is as follows: >> >> 1. trigger a 12-bit resolution conversion on each sensor for >> initialization. >> 2. write soemthing to /simultaneous/temperature to trigger all >> temperature conversions at the same time. >> 3. wait a second >> 4. read /uncached/<sensorid>/latesttemp of each sensor >> 5. If the result for a sensor is not 85°C, store and go to 2. >> 6. 85°C. Check the resolution. If it is still 12 bit, that's a valid >> reading. Store and go to 2. >> 7. Power-on-reset. Store an error. Trigger a 12-bit resolution >> conversion for that sensor and go to 2. >> >> >> Kind regards >> >> Jan >> >> >> _______________________________________________ >> Owfs-developers mailing list >> Owfs-developers@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/owfs-developers > > > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
