Issues with DS1820B Sensor Temperature Reporting - Negative temperature and reports to HA

Actually this "simple" driver only supports one device. One restriction is that for small code we simply ask "all devices" and not a dedicated one.
It's even not possible to have multiple devices on different pins: the DS1820 code would work in this case ("all" devices is on), but handling more than one pin is just not implemented.
There is some more complete DS1820 code, but it never was fully adapted yet.
Maybe, if I have some spare time ...

We can try to get some DS18B20 with @DeDaMrAz and help, what exatly is left to be done? To be ported? I guess something that looks like I2C scan? I don't know OneWire protocol well..

If I remember correctly, the DS18(X)20 code is already in git. It probably will be something like porting the usleep from the "simple " code to the complete one and add some code to get and display the results.

@sx642005elektroda what kind of device do you use?
I'm trying to add the other driver which allows multiple DS18B20 or maybe just extend the actual one.
I will add a testing version the next days for I don't have multiple sensors to test the code during the week...

@max4elektroda

do you have a compiled OTA for N module where I can test that DS sensor again?? And of course share if you have that, thanks.

I use this DS18B20 on this image "OpenBK7231N_1.17.780.rbl".
I tested these 2 sensors on tasmota which detects the 2 together. As the platform I will use has a BK731N chip, OpenBeken is the solution for my need.
I changed the value several times (0 then 1 then 2) in the channel field associated with the DS1820_IO module, but it had no effect.

Added after 7 [minutes]:

Désolé @max4elektroda, je n'avais pas lu ta réponse du 01 Dec 2024 19:18 ( #31 21328160) avant de faire ma réponse.

Added after 33 [seconds]:

English version
Sorry @max4elektroda, I didn't read your answer of 01 Dec 2024 19:18 (#31 21328160) before making my answer.

O.k., as I'm busy today, please find my first try for BK7231N attached.
Define pin like other driver - or keep definition, if already done

Thank you max4elektroda, I read your message way too late. I'll test this new version later (tomorrow), I'm going to bed!

First code can be found here:
https://github.com/MaxineMuster/OpenBK7231T_App/tree/DS1820_full_wip



Added after 9 [minutes]:

Hi max4elektroda,

I tested your dev version (dev_20241203_072219) then the latest (1.17.794), and I get the same result, still an error.
I also changed the number of channels (0 to 2) without effect.
This is the error message with dev_20241203_072219 version :
Info:SENSOR:DS1820[0] - Starting conversion
Info:SENSOR:DS1820[0] - Temp=23.12
Error:SENSOR:DS1820[0] - Read CRC=40 != calculated:c7 (errcount=1)
Error:SENSOR:DS1820[0] - Scratchpad Data Read: 70 1 55 5 7f a5 a5 66 40
Error:SENSOR:DS1820[0] - Read CRC=40 != calculated:c7 (errcount=2)
Error:SENSOR:DS1820[0] - Scratchpad Data Read: 70 1 55 5 7f a5 a5 66 40
Error:SENSOR:DS1820[0] - Read CRC=40 != calculated:c7 (errcount=3)

The latest version won't help, the new driver is only in the testing branch or in the zip file.
Seems you did activate the "old" driver, but to test the new one, you need to run (only!) the new driver with

Please note the B between 18 and 20.

I'm trying to get this sensor working in home assistant. I've set up the pin and channel and started the driver; the device is shown at the first page and shows values correctly.

But I can't seem to be able to get that value to publish to homeassistant.

Any ideas what to configure? I've set the DS1820 to channel 1

Set channel type to Temperature.

He publishes the temperature to MQTT as soon as it changes by 0.06 degrees, but it changes with every measurement on the DS18B20 sensor. How can I set it up so the temperature is sent once every 5 minutes or when it changes by 0.2 degrees? (Learning C is easier than OpenBeken.)

Usually that's intended to have the actual temperature, for "no message" can mean "no change in temperature" or "the device/sensor doesn't report any temperature" (might be dead).
But I can check if/how it would be possible to change the behavior by either sending updates only every X seconds, regardless if it changed or not or introduce a minimum change needed to trigger an update (which might lead to the problems mentioned above)

Added after 5 [minutes]:

Btw, thinking it over again: it should be possible even now to change the interval of updates:
Calling the driver with an additional value is possible.
So if you start it with

startDriver DS1820 300

should trigger a reading of the sensor every 5 minutes and hence the updates should follow the readings.

Hi guys,
Today I've upgraded the version of OpenBeken to version 1.18.94 and now the DS1820 sensor that I have does not communicate anymore.
In the logs I receive errors about bad CRC.



Before that, I was running on version 1.17.754 and this same sensor was working fine. Only I had occasional reboots of the micro-controller and it triggered the relay rapidly. Which was disturbing the compressor of my freezer.

I read somewhere to try the DS18B20 driver, but I cannot seem to find it?

Hey, can you help us and narrow down which version breaks DS18B20 for you?

This works for me on at least 1.18.92 and 1.18.95 tested



Do you have a pullup resistor on the DS data line?

imvaloo wrote:

oday I've upgraded the version of OpenBeken to version 1.18.94

You use a BK7231N, right?

Beken timing is kind of unreliable, but there is another approach form git user "rpv-tomsk" for timing which is very promising (https://github.com/openshwprojects/OpenBK7231T_App/pull/1579).
I made some slight changes, you may try this version from here (if you have a git user to download the artifacts:
https://github.com/MaxineMuster/OpenBK7231T_App/actions/runs/14796474485

Added after 30 [minutes]:

Just tried here with the version you mentioned:
"Built on Apr 25 2025 15:29:36 version 1.18.94"
Works for me on BK7231N with my DS18B20 clones