Repository navigation
Replies: 7 comments 4 replies
|
FWIW, I'm using SCD40 (not SCD41, but same driver) on Tasmota 12.2, no problems. |
0 replies
|
Could be a i2c bus problem. Does the sensor work if you remove the other i2c sensors? |
0 replies
|
Maybe. For testing I desoldered the pull-up resistors from the sensor board and now the sensor works when nothing else is connected. Does Tasmota activates the internal pull-up resistors on the I2C pins? It's strange that it worked on version 12.1.0.0. |
0 replies
|
i2c is a bus. For a correct bus setup the last device (seen from wiring) should only be terminated with pull up resistors. Lower resistors are more resilent against "noise". |
0 replies
|
Supply is stable, wires are short (5cm) and I sodered an extra decoupling cap near the sensor because noise was one of my assumptions. So I used my logic analyzer an here are the results: 0x62 SCD41 Address Good Version with 12.1.0.0 everthing looks normal: DetailsVersion 12.2.0.6: DetailsI think it's the combination of SCD41 and SGP30. Maybe someone has this combo running and can report whether it works for the person otherwise I will look deeper in the sources. |
1 reply
|
There does appear to be some conflict. When I added a SGP30 to the board with SCD40, the SGP30 visible on I2C address 0x58 was not detected by the Tasmota driver, even when having the driver for the SCD40 disabled. Only after unplugging the SCD40 breakout board, the SGP30 became detected in addition to only being visible on the bus. |
|
After a few tests it looks like that the SGP40 implementation has a problem. When only one implementation is active (SGP30 or SGP40) everything runs as expected (expect i2cscan {"I2CScan":"Error 5 at 0x02"}). When both are enabled the bug happens. |
1 reply
|
With I2CScan errors, I'd first triple-check for appropriate wiring and good power. |
|
Have this problem on 12.3.1.4/ESP32. SCD40 is a breakout module with pullups and a cap. No other devices on I2C. Sensor is found at the correct address, then 3x "SCD40: no data available", then one correct reading, and then no data again. No reaction to any SCD40 command. Any other I2C sensors work. |
2 replies
|
Make sure to have a good power supply. According to Sensirion, SCD40 may need up to 205 mA of power, which is much more than "typical" sensors. Powering via 5V or 3.3V may make a difference, your board may not have enough 3.3V to spare. And of course how you power the whole setup matters too. Anyway, getting "no data available" may not mean much, if you still get good readings. CO₂ is not a type of measurement highly dependent on updates every second. I'm also seeing such messages, but found no reason to call it a "problem" in my SCD40+ESP32 setups. |
|
Seems like it is a logging problem. In fact, the values update according to the teleperiod set, while with the loglevel >=3 the log is flooded with "no data available" Commands and responses yet to check |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Uh oh!
There was an error while loading. Please reload this page.
PROBLEM DESCRIPTION
A clear and concise description of what the problem is.
Hi,
the CO² sensor SCD41 no longer works under the Tasmota 12.2.0.0 (and 12.2.0.6). In the version 12.1.0.0 the sensor works normal. I use the Adafruit QT Py ESP32-C3 board with the SCD40, SGP30 and VINDRIKTNING sensor. A WS2812 LED is also used. I looked into the Tasmota libs for sensor control and i2c control but i can't find a change the explains this behavior.
Hope my informations can help you.
REQUESTED INFORMATION
Make sure your have performed every step and checked the applicable boxes before submitting your issue. Thank you!
Backlog Template; Module; GPIO 255:Backlog Rule1; Rule2; Rule3:Status 0:weblogto 4 and then, when you experience your issue, provide the output of the Console log:TO REPRODUCE
Steps to reproduce the behavior:
Connect SCD41 with QT Py ESP32-C3.
EXPECTED BEHAVIOUR
A clear and concise description of what you expected to happen.
Normal read out from the SCD41 sensor
SCREENSHOTS
If applicable, add screenshots to help explain your problem.
ADDITIONAL CONTEXT
Add any other context about the problem here.
(Please, remember to close the issue when the problem has been addressed)
All reactions