MH-Z19B - MHZ19: Unknown response: 0 0 0 0 0 0 0 0 0

[dgcracker]

Thx for reply. I have loaded test file into nodemcu v3 and there is no change. Still can't read sensor values. Only in logs I see messages “MHZ19: Unstable reading, ignoring! PPM value: 776 ...." PPM and Temp in logs are changing but each read of sensor values report "Unstable reading....". Sensor red leds are blinking from time to time so it looks like sensor is OK. Any ideas?
Thank you for help!

[timbiker]

Thx for reply. I have loaded test file into nodemcu v3 and there is no change. Still can't read sensor values. Only in logs I see messages “MHZ19: Unstable reading, ignoring! PPM value: 776 ...." PPM and Temp in logs are changing but each read of sensor values report "Unstable reading....". Sensor red leds are blinking from time to time so it looks like sensor is OK. Any ideas?
Thank you for help!

I already had this issue and T-Der answered me. That's because you have the B version of the sensor. Like me

You have to get the MH-Z19 plugin from the "2.0" branch of the Espeasy github

[TD-er]

You seem to have the "B" version of the sensor, which gives a "0" as S-value.
Starting version dev-13, this will be supported, but you can also compile a version for yourself if you need it faster.
I don't think the new dev-13 release will take long, since the last 2 days, a lot of pull requests were merged and I think it is only testing for a (short) while with these new versions before the new release will be created.

[dgcracker]

Thx for reply and help. Exactly I have "B" version. So I have to wait for dev-13 or in the meantime compile it myself

[dmq]

But I though about that today, I recently wasted my time in having a lot of issue on a project. I just solved them in changing my power supply : as this sensor is quite hungry during peak, check with a good power supply and a good cable

Ah, timbiker. Cool. I just changed the power supply and now I have the same state as dgcracker, because I own the same B version. But it works.

Thanks TD-er and timbiker!

[dmq]

Just for information. The old power supply was rated at 5VDC/2A and the measurement was stable. The new one has the exact same values but works.

[dmq]

You seem to have the "B" version of the sensor, which gives a "0" as S-value.
Starting version dev-13, this will be supported, but you can also compile a version for yourself if you need it faster.
I don't think the new dev-13 release will take long, since the last 2 days, a lot of pull requests were merged and I think it is only testing for a (short) while with these new versions before the new release will be created.

Did already tested someone the dev-13 release and the "B" version? At the moment I have no access.

Thanks.

[TD-er]

You seem to have the "B" version of the sensor, which gives a "0" as S-value.
Starting version dev-13, this will be supported, but you can also compile a version for yourself if you need it faster.
I don't think the new dev-13 release will take long, since the last 2 days, a lot of pull requests were merged and I think it is only testing for a (short) while with these new versions before the new release will be created.

Did already tested someone the dev-13 release and the "B" version? At the moment I have no access.

Thanks.

Ehh I don't understand your post (maybe lack of coffee, or sleep, or both )
Is your question about whether someone tested the latest builds? (both v2.0 and Mega have nightly builds now)
Or did you test it and it still doesn't work?

[dmq]

Ehh I don't understand your post (maybe lack of coffee, or sleep, or both )

Nope, you were perfectly ok. I think I had too much coffee

Is your question about whether someone tested the latest builds? (both v2.0 and Mega have nightly builds now)

Yes, exactly. You wrote in another post:

You seem to have the "B" version of the sensor, which gives a "0" as S-value.
Starting version dev-13, this will be supported, but you can also compile a version for yourself if you need it faster.

Question is, if someone with this version of the sensor now can see the correct values in the interface and not only in the logs.

Thanks.

[TD-er]

With the latest builds, the B version of the sensor is fully supported.
I run one here for a while now.

[dmq]

Very good. Thanks.