Dallas DS18b20 strage behaviour

[dproetel]

Good morning,

one of my ESPeasys has a strage behaviour. It should send data to a fhem system. After a while the sensor stop sending date. Rebooting helps sometimes, sometimes just edit the sensor .

All of the times, the webside of the esp shows sensefull data. In the log (Debug dev 9) no sensor request is logged. any hints?

[grovkillen]

Version?

[dproetel]

Soory,
mega-20190925 and mega-20191208 tested.

ciao Daniel

[grovkillen]

And you know the signal is good enough? How long are the cables etc?

[dproetel]

Hi, cable around 3 m with 2 connectors. Never had the problem that one sensor doesn't show his id in espeasy.When editing the sensor and just press save a value is transmitted, but not based on the timing which is entered.

[grovkillen]

Are the wires twisted?

[dproetel]

Yes, I am using J-Y(St)Y 10x2x0,6

with an raspberry pi attached the sensors are working fine.

[grovkillen]

Can you please get more info for us to work with? How are the sensor powered etc?

[mrwee]

I am also struggling with DS18x20 sensors.

Setup:
Official Wemos D1 Mini Pro 2.0
6 x DS18S20 on 1,2m twisted cable
DS18S20 are connected to GPIO-16
Powering D1 Mini Pro via USB (Have also tried 5V)
DS18S20 are 3,3V powered from the Mini Pro
Resister for DS18S20 is 4,7K
Mega 20191208, pre-built bin
First flashed with blank, then the firmware. All seems normal

My observations:

• Configuring the individual devices, seems unstable. Temperature reading can be 0.0, but if I reconfigure a device (e.g. change error value), then the correct temperature is shown.
  Changing error value between NaN, 0, 125, -127 and ignore, sometimes revert to the old value, sometimes I don't get any sensor data.
  Often I cannot change resolution either. It often reverts back to 12 bit or doesn't work at all.
  In the device list, temperature sometimes switch between NaN and nan (If error level is set to "NaN")

I feel confident that all DS18S20 are soldered fine, and the above observations are done while the setup is physically untouched.

Is there an earlier version which have proven stable with multiple DS18S20, which I could test as a reference?

[TD-er]

Please try another GPIO pin as GPIO-16 is a bit different compared to the other pins.
See: https://espeasy.readthedocs.io/en/lates ... on-esp8266


Also there are a lot of counterfeit Dallas sensors on the market.
Some report that counterfeit Dallas sensors may work fine when using only a single one, but may fail when using multiple (>3 for example)

[mrwee]

Good input, thanks. Will try another GPIO. They should be the real thing, as they're bought from an official shop.

[mrwee]

Update: re-flashed to mega-20200204 and moved to GPIO-14. Seems to work like a charm! Thanks for the hint