Quote:
Originally Posted by Daox
...The noise in the lines must be fairly easily overriding this though.
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One of the great things about 1-wire is that if a spike occurs during a packet transmission, instead of an erroneous data being acted upon, the affected packet is viewed as corrupt, so it is rejected.
Quote:
Originally Posted by Daox
I also added additional on time delays to the latest version that I'm running. When it turns on, it turns on for 30 seconds no matter what. This can probably be extended so its a few minutes as AC Hacker suggested. I've kept the off time delay short in case a spike happens it can kick back on relatively quickly. I think its set to ~5 seconds right now.
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By "spike" do you mean a thermal spike?
It occurs to me that your sensors might be mounted sub-optimally. If you have them exposed, the slightest stirring of the air would create erratic behavior.
When I mounted the outdoor sensor for my whole house temperature logging project, I knew that wind & rain would have a disturbing effect on my data, so I enclosed the sensor inside a plastic plumbing pipe assembly, with the sensor at the top, but held away from any plastic. The assembly has small holes that will allow air flow but not bug flow.
I had a similar problem with the sensor in my Freezerator. I had to shield it from the environment enough so that it was not affected by short term events (drips of condensation) but still able to detect changes of temperature.
So I guess that it is mechanical hysterisis, rather than software hysterisis.
Quote:
Originally Posted by Daox
I do not have an SD card logger. It would come in quite handy though! Right now I just have some serial printing in the code to show some things.
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This little jewel has an SD card ability, and also a serial port for remote logging, AND it is open source with source code (that will work in the Arduino IDE) available for customization.
(Did I mention it has a header ready to accept a string of 1-wire sensors (70 sensors have been tested to work, maybe more... Travis ran out of 1-wire sensors to test).
You could even build a small trickle-charged battery that would keep it going in case of a power loss.
-AC