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]

Today, I tried to use Arduino UNO to connect with my sensor via I2C. Arduino UNO correctly shows that my address is 0x21. If I change the resistor value at ADDR, the address will be changed to 0x21 or 0x22 or 0x23 successfully (see datasheet page 4, section 3.3). 

However, Nordic nRF52 DK (nRF52832) shows my address is still 0x20 no matter which resistor value I use at the ADDR port. 

So I guess it's something wrong in code or nRF52 DK. 

[Einar Thorsrud]

Hi,

This is puzzling... Can you upload a corresponding plot from when using the Android device so that I can compare with the nRF5 device? Also, if you can upload the full code for Android as well that would be good. Are you using the same configuration in other regards, same frequency?