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Unreliable DS18B20 Readings
#20
That one with cable is sure being stubborn, it seems something might be up with it. As it returns -1 that is bad data, the sensor was seen on the bus but data was no good, normally that does point to a flaky sensor. I think it's also less likely that bus will lock up for that sensor as there's no extra resistance on the line from other sensors and of course the extra filtering could help although they don't do a whole lot unless located right at the sensor, the controller also has a bypass filter on the 5v rails to each port. So yeah that sensor may be no good with reef-pi as it doesn't seem to validate, hang on to it though for when you switch to my app at some point, if that happens it will just read the sensor again so you'll never know it's happening and it won't affect anything.

The 4.7k pullup is on the board, one for the 3 temp sensor ports and on the sensor port if one of the jumpers is set to P-U as you have that's a 4.7k pullup. The P-D means 4.7k pulldown.
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Messages In This Thread
Unreliable DS18B20 Readings - by pwest - 06-19-2021, 09:04 AM
RE: Unreliable DS18B20 Readings - by Rob F - 06-19-2021, 02:34 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-19-2021, 04:25 PM
RE: Unreliable DS18B20 Readings - by Rob F - 06-19-2021, 05:28 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-19-2021, 06:56 PM
RE: Unreliable DS18B20 Readings - by Rob F - 06-19-2021, 07:26 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-20-2021, 01:56 PM
RE: Unreliable DS18B20 Readings - by Rob F - 06-20-2021, 03:07 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-20-2021, 04:17 PM
RE: Unreliable DS18B20 Readings - by Rob F - 06-20-2021, 04:39 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-26-2021, 09:22 AM
RE: Unreliable DS18B20 Readings - by Rob F - 06-26-2021, 02:52 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-26-2021, 04:27 PM
RE: Unreliable DS18B20 Readings - by Rob F - 06-26-2021, 04:41 PM
RE: Unreliable DS18B20 Readings - by pwest - 06-26-2021, 05:07 PM
RE: Unreliable DS18B20 Readings - by Rob F - 06-26-2021, 05:50 PM
RE: Unreliable DS18B20 Readings - by pwest - 07-04-2021, 03:33 PM
RE: Unreliable DS18B20 Readings - by Rob F - 07-04-2021, 07:10 PM
RE: Unreliable DS18B20 Readings - by pwest - 07-10-2021, 04:14 PM
RE: Unreliable DS18B20 Readings - by Rob F - 07-10-2021, 05:18 PM

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