Re: [Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-31 Thread Ralph Corderoy
Hi Terry, Graeme wrote: > > 4. I see no reason for the values of electrical signals to have > > changed They could if any were incorrectly left floating, like Vdd when parasitically powered. -- Cheers, Ralph. -- Next meeting: BEC, Bournemouth, Tuesday, 2020-01-07 20:00 Check to whom you a

Re: [Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-31 Thread Terry Coles
On Monday, 30 December 2019 16:17:18 GMT Graeme Gemmill wrote: > 1. All my sensors are mounted on small circuit boards bought from (now > defunct) American company Hobby Boards. I believe the temperature > sensors are powered parasitically, though there is a 5v power injector > to feed a humidity m

Re: [Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-30 Thread Graeme Gemmill
Ralph, Terry: thanks for your comments. 1. All my sensors are mounted on small circuit boards bought from (now defunct) American company Hobby Boards. I believe the temperature sensors are powered parasitically, though there is a 5v power injector to feed a humidity meter. 2. They are connec

Re: [Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-28 Thread Terry Coles
On Saturday, 28 December 2019 14:54:52 GMT Terry Coles wrote: > I'm not sure what to suggest from a diagnostic point of view other than > measuring the voltage levels with a multimeter when the clock pin is > disconnected and simply programmed to high. Measuring the frequency and > pulse shape is

Re: [Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-28 Thread Terry Coles
On Saturday, 28 December 2019 14:12:14 GMT Graeme Gemmill wrote: > I have two 1-wire nets connected to raspberry PIs. The first includes > two DS1820 temperature sensors and a humidity sensor based on the > DS2438, which also incorporates an unspecified temperature sensor. The > second net just co

Re: [Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-28 Thread Ralph Corderoy
Hi Graeme, > I have two 1-wire nets connected to raspberry PIs. The first includes > two DS1820 temperature sensors and a humidity sensor based on the > DS2438, which also incorporates an unspecified temperature sensor.  > The second net just contains a humidity sensor with, again, > unspecified t

[Dorset] Strange behaviour of DS1820 temperature sensors

2019-12-28 Thread Graeme Gemmill
I have two 1-wire nets connected to raspberry PIs. The first includes two DS1820 temperature sensors and a humidity sensor based on the DS2438, which also incorporates an unspecified temperature sensor.  The second net just contains a humidity sensor with, again, unspecified temperature sensor.