problemwith sensair co2 sensor

[BartSr]

Hi I hooked up the sensor to a nodemcu.
G and 3V to supply the sensor D9 - D10 for communication
The sensor only displays 10000PPM after callibration (bcal to ground for 5 sec) it shows 0 ppm
Any suggestion?
Datasheet says powervoltage 5V. Might this be causing the problem?
Temp display is OK.
KR
-Bart

[TD-er]

Yep, it must be powered by 5V (and not > 5.25V as it will damage the sensor)

And secondly, and I keep repeating myself over-and-over again, do NOT!!! try to calibrate a CO2 sensor as you can't do it yourself.

Pulling bCal to GND for 4 - 8 seconds will let the sensor assume the current CO2 concentration is 400 ppm (which it isn't as you're breathing on it, so you're seriously messing with the factory calibration)

But here's the really pain when messing with this pin;
When closed for minimal 16 seconds, you're entering 0 ppm CO2 sensor exposure.

So in short:
Let's hope you "only" messed with the 400 ppm level.
If so, then hopefully the sensor will get in proper ranges again in a few weeks (!!!)
If you shorted this pin for too long, you essentially destroyed the factory calibration and it is next to impossible to do it correct.

Let's say it once more....
Do NOT!!!!!!!
I repeat, do NOT!!!!
try to force calibration on CO2 sensors yourself.