MLX90614 with ESp8266 and EspEasy 1037.55

[Dondolo]

MLX90614 with ESp8266 and EspEasy 1037.55


Hi there,
the MLX90614 IC2 infrared sensor only shows 1037.55.

unfortunately I only get the value 1037.55 regardless of whether the object or ambient temperature is
displayed under ESP_Easy_mega_20201022_normal_ESP8266_4M1M.
Initially, and only as a flash, a realistic temperature value was displayed.

Have already tried the following without success:
- current and older version of EspEasy installed
-3V or 5V
-IC2 clocking set to 100000Hz, connected alone or with another sensor
-ESP8266 changed
-IC2 used with pullup, IC2 address is 05xA

Anyone have an idea what else I could do?

[TD-er]

Hmm that plugin is not changed for a while and also not a lot of issues about it.
So either the issue you're seeing is perhaps more hardware related, or it isn't used a lot.

What value of pull-up resistors do you use?
How long is the cable?
Does the sensor show up at that address when you perform an I2C scan?

[Dondolo]

Hi TD-er,
Thanks for the feedback.

Do you mean that the sensor is defective?

First I tried the internal resistors,
then with 10kOhm, 3.3kOhm and with 50kOhm everything was unsuccessful.

With an LCD and an ADS115 on the IC2 bus, I occasionally get values.
The cable is approx. 20 cm long.
The address for the IC2 scan is displayed with 0x5A.

Code: Select all

26538: EVENT: infrarot#Temperature=1037.55
26577: ACT  : lcd,1,1,1037.55
26638: EVENT: DummyCo2#Co2=0.00
26738: EVENT: DummyCo2#=0.00
27491: MLX90614  : Temperature: 23.45

[TD-er]

I'm not sure if it is defective.
More likely the connection is flaky.

Which pins do you use for the I2C? Just the standard ones? (4 & 5)

20 cm long wire should not be a problem.
And if you're using some kind of pull-up resistors (when they are not already present on the sensor boards) between 3k and 10k it should be OK.

With an LCD and an ADS115 on the IC2 bus, I occasionally get values.

That sounds like those are also flaky?

[Dondolo]

Hi,
yes i use standard pin D4 / D5 for IC2.
The sensor is installed on a breakboard with 2 x10kOhm resistors,
Actually, it doesn't need any additional resistance.
The LCD works fine, the IC2 connection works.
I assume that it is defective or processed improperly.
Let's see if I can exchange the sensor.
Thanks for your support.
Greetings Dondolo

[Ath]

Please check your wires, I've seen so many of those cheap breakout-board wires having no, or bad, connections inside, I test 'm all individually using a multimeter (and wiggling the wire a bit) before ever using them, to avoid any dissappointment.

[TD-er]

Maybe also check with a build of roughly a year ago.
A while ago (not sure about the timeline...) the code for I2C was changed in the esp8266/Arduino core.
This lead to a number of sensors showing issues. Most of those issues were resolved by lowering the I2C clock for them, but that's something you already tried.
Still I would love to know if it does work with a version of let's say Q1 of 2020.

[Dondolo]

Please check your wires, I've seen so many of those cheap breakout-board wires having no, or bad, connections inside, I test 'm all individually using a multimeter (and wiggling the wire a bit) before ever using them, to avoid any dissappointment.

Hi Ath,
checked all cables and used them without a breakboard. Nothing helped but the note from TD-er below helped, thanks for the support.

[Dondolo]

Maybe also check with a build of roughly a year ago.
A while ago (not sure about the timeline...) the code for I2C was changed in the esp8266/Arduino core.
This lead to a number of sensors showing issues. Most of those issues were resolved by lowering the I2C clock for them, but that's something you already tried.
Still I would love to know if it does work with a version of let's say Q1 of 2020.

Thanks for the hint, it worked stably with the following version.

ESP_Easy_mega-20200204_normal_ESP8266_4M1M.bin

Can I then no longer update the current version?

[TD-er]

[...]

Can I then no longer update the current version?

Not sure if you kept an eye on the commits for this repo?
Whenever we find such a problem we try to fix it.
So for now, until it is fixed, you should use an older version for this specific setup.

[ce4]

Thanks for the hint with the old version, had the same issue with the MLX90614 sensor.
Anything that I can do to help you guys with debugging?

[TD-er]

I have ordered one, so as soon as that one arrives, I will have a look at the plugin and when I have a test build, I will try to remember to post it here also (made an issue for it on GitHub)