UNO and SCD30 CO2 sensor I2C

[eagleeyesg58]

Hi
I have been reading that the SCD30 CO2 sensor I2C is
compatible at 3volts for I2c but the UNO's I2C communications
is at 5 volts..

I noticed diagrams hooking up the SCD30 to the UNO without
any level shifting... won't this blow the SCD30 overtime?

Am looking for an explanation.

[kolaha]

@eagleeyesg58

SCD30

...

[Koepel]

@kolaha

need you more explanation?

Yes, because you show that the I2C voltage level should not exceed 3.0V.

Manufacturer's page of the SCD30: https://www.sensirion.com/products/catalog/SCD30/

Datasheet:

The power can be 3.3V to 5.5V, but the SDA and SCL need a I2C bidirectional level shifter.
The same pins in Modbus mode allow up to 5.5V, so it is weird, but I suggest to follow the datasheet and use level shifters.

@eagleeyesg58

won't this blow the SCD30 overtime?

That is hard to tell. Maybe it does not matter at all. The datasheet has guaranteed safe numbers after all. No one knows the real limits. Maybe something inside can heat up. The Bosch sensors are less accurate with voltage levels that are too high. Some sensors stop working. It is vague. That is what the datasheet is for, to stay away from any vague situation.

[kolaha]

ah, yes, sorry, my bad.
i got one such, 86€, connect to arduino and it is not better as CCS811(8€) or MH-Z19C(17€).

[eagleeyesg58]

HI Ok I finally found a Carrier board for I2C for the SCD30 that has level shifters
for the I2C pins.

Thanks for all the input.

[kolaha]

co-ol