martin010 wrote:Hi All,
When the unit is left alone in the room overnight values are roughly about ~425 PPM for the CO2 and about ~10 PPB for the VOC. Now when people enter the room in the morning, the sensor very quickly spikes till its maximum values for both the CO2 and VOC. When I rest the unit, all the values are normal..
Is this behaviour normal? Should I normalise values for a certain amount of time before using them?
martin010 wrote:Hi All,
When the unit is left alone in the room overnight values are roughly about ~425 PPM for the CO2 and about ~10 PPB for the VOC. Now when people enter the room in the morning, the sensor very quickly spikes till its maximum values for both the CO2 and VOC. When I rest the unit, all the values are normal..
Is this behaviour normal? Should I normalise values for a certain amount of time before using them?
I still have to do the measurements mike suggested though.
Hi Backdraft,
I kind of guessed it as Mike describes is.. It's consistent when the room is empty for a while and suddenly you start to cook, or come in with a few persons. It settles down in the end though. How did you fixed it? something coded?
Same problem here. Using a Adafruit HUZZAH ESP8266 with the Adafruit CSS811. The CSS hangs up at least once an hour. I also connect a wire from the ESP to the CSS RST line to reset the CSS, if it hangs up.
I like to change the "ClockStetchLimit" like Alex but I can't find the "core_esp8266_si2c.c" at my linux machine.
Haven't had any issues after changing the twi_setClockStretchLimit..no resets, all works fine. Had to redo this when 2.4.0 came out though..
On the mac you can find it here: /Library/Arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_si2c.c
Thank change Line 74: twi_setClockStretchLimit(230) ---> twi_setClockStretchLimit(460);
Thank you very much. At Linux you can find it at:
/home/[username]/.arduino15/packages/esp8266/hardware/esp8266/2.4.0/cores/esp8266/core_esp8266_si2c.c
I haven't tried it yet but looks good. Thank you, Simone.
Ohhh... Unfortunately it does not help for me. My ESP8266 + CCS811 still make I2C error and kill I2C bus after 10...20 minutes... It look like setClockStretchLimit(500) in this place have no effect.
That's interesting. At the beginning, the fix in the CCS811 Lib solved my I²C problem. But before a couple of days I started a new project with the CCS811 and got this I²C problems, again. Even though I used the new I²C Lib.
Only after I edited the twi_setClockStrechLimit() in core_esp8266_si2c.c the problems are gone.
Follow up on the discussion, I am also seeing some strange CCS811 readings. I have 4 in the office space and after few month of deployment, the one on my desk starts to fluctuate a lot. Reset seems to bring the sensor back to normal reading (for a few hours at least) and it seems not every one of the CCS811 has the same problem. My question is how often do I need to toggle the CCS811 reset line to get the value back to reasonable range?
drafted reading
IMG_9193.jpeg (177.12 KiB) Viewed 519 times
IMG_9194.jpeg (173.38 KiB) Viewed 519 times
These are the recent reading examples. Any suggestion for best practice with CCS811?