CCS811 air quality sensor kills some other function

Other Hardware Sensors
1

Hello,
I have built a weather station comprising 4 sensors driven by a Nano 33 iot.
All it worked fine for a while, then, for some unknown reason, it started to fail.
I changed the Nano board, thinking it may be it, but no, it didn't solve.
After a long fault finding search, I discovered that it was the CCS811 Air sensor that some how "pulled down" the system and even prevented the Nano to connect to the WiFi.
I have discovered that if I detach the +V wire from the sensor, all starts to work fine, except the air sensor, of course.
As soon as I attach again the +v wire, the WiFi communication drops and all comes to a stop.
The sensor is attached to a I2C bus, together with another 2 sensors, a BMP280 barometer and a SHT31 temp and humidity sensor, On the same I2C there is also an Oled display.
The question is, since there is no short circuit to the +Vcc and -Vcc I2C bus, because even when I connect all the wires, the voltage is fine and the Oled display works fine.
So, the I2C bus is still operating, as indicated by the fact that the Oled display still works, how is it possible that the faulty sensor kills the board wifi and other functions ?
Did anyone ever experience similar problems ?
I will eventually try to change the CCS811 sensor, to see if it all start working again. Be it, that if I disconnect it, all seem to work fine.
Tried to scan the I2C ports and I get the reading of all addresses, including the supposed faulty sensor.
Here are the port scans:
Without the sensor connected
Scanning...
I2C device found at address 0x44 !
I2C device found at address 0x60 !
I2C device found at address 0x6A !
I2C device found at address 0x77 !
done

And with the incriminated sensor connected
Scanning...
I2C device found at address 0x44 !
I2C device found at address 0x5A ! <------
I2C device found at address 0x60 !
I2C device found at address 0x6A !
I2C device found at address 0x77 !
done

Now I am totally confused...

2

Lots of people. The problem is usually faulty system design or construction: insufficient power supply capability, overloading the Arduino 5V or 3.3V output, drawing too much current from output pins, poor I2C wiring or incorrect I2C pullup resistors, etc.

Please post links to the data sheets or product pages for the sensors and the power supply and also, a carefully labeled wiring diagram (not Fritzing, hand drawn preferred) of the entire setup.

3

Hello Jremington,

my fault !

Thanks to you, as I went to search for the data sheet, I realized that it has a 5V supply and not a 3.3V as I beleived it had. Nano 33 Iot is currently working at 3.3V.

Somehow I must have missed this parameter when I sourced the item and I was confident it was a 3.3V device.

I am going to get a new sensor that operates on 3.3V and see what happens.

I feel so bad, it was so simple, just slipped my attention, how could I have made such a silly mistake… ;-(

Thanks again.

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