- Thu Nov 26, 2015 12:12 am
#35022
I have a few esp modules with ds18b20 attached. Mostly they work fine (I use nodemcu fw).
For the last few weeks I see, from time to time, the module returns an incorrect reading (mostly up to 1dC off) and the following reading is correct again. I attached a few (up to 4) sensors to a module and I noticed that this failure happens to all the sensors at the same time.
Also, at one time a module went completely bad and practically every reading was off, but always within about 1dC error. See example here. The same sensor was tested later and it worked properly.
This is not a problem with the ow protocol as the checksum is correct. I suspect a power issue, but I do not see any other indications of bad power (it runs off fully charged batteries using an LDO). I would like to hear from others who may have experienced such events and how they resolved it.
TIA
For the last few weeks I see, from time to time, the module returns an incorrect reading (mostly up to 1dC off) and the following reading is correct again. I attached a few (up to 4) sensors to a module and I noticed that this failure happens to all the sensors at the same time.
Also, at one time a module went completely bad and practically every reading was off, but always within about 1dC error. See example here. The same sensor was tested later and it worked properly.
This is not a problem with the ow protocol as the checksum is correct. I suspect a power issue, but I do not see any other indications of bad power (it runs off fully charged batteries using an LDO). I would like to hear from others who may have experienced such events and how they resolved it.
TIA
