TWI Scanner I2C address is 1 bit wrong

[StevenW807]

I'm using <TWI Scanner> example on nRF52 DK to find my sensor's address.

According to the sensor datasheet, the sensor's address is 0x21. However, <TWI Scanner> finds the address at 0x20. 

Any idea, please? 

[StevenW807]

I used this Arduino code from Github. Please remember to uncomment the code at line 13, which is used to customize the I2C address. If I change line 13 as I2C address 0x21, my sensor works well. For all other I2C addresses, my sensor has no data output. 

[Einar Thorsrud]

Hi,

I see. Can you also make plots of the exact same read operation as you do from the nRF? I would like to see a comparison in order to understand more. Unfortunately I do not have the SDP31 so I am not able to test with that on my side.