TWI Error NRF_TWI_ERROR_ADDRESS_NACK

[arjun]

Hi guys,

I am trying to interface nrf52832 with PMIC(BQ25121). I have earlier interfaced PMIC with nrf52832 successfully, and I am using the same code. However this time, I am getting NRF_TWI_ERROR_ADDRESS_NACK error.

I have looked over the error, and verified that my pin mappings are correct.

I could check for the scl/sda voltage levels in logic analyser, however I can't take scl/sda lines, as mine is a custom board.

Could anyone suggest any other possible causes and means to rectify this error....

[Sigurd]

Hi,

Are you using the correct address? Try the twi_scanner example in the SDK, and see if you can find the device. Also sometimes you have to shift the address left or right, see this post.

[arjun]

Hi Sigurd,

As I have mentioned above, I have earlier interfaced the PMIC with nrf52832, and I am using the same code here also. So I believe the address should be correct. However I made sure that the address is correct by checking the datasheet (7 bit address 0x6A).

Is there any configuration setting that I may be missing..

[Sigurd]

• What SDK version are you using? is it the same version as you used last time?
• Does this happen on several custom boards? or just this one?

It could be hard to debug TWI issues without a logic analyzer.

[arjun]

I am using sdk version 11. Yeah, it is the same version that I used last time.

I tried it with two different custom boards, but in both the cases, I get the same result.

[Sigurd]

When do you get the NRF_TWI_ERROR_ADDRESS_NACK error? Is there a specific register you try to read or write when this happens? Did you test the twi_scanner example ?

You should check for broken traces or wires, wrong address, noise making the address look wrong, weak/strong pullups distorting the data and bad power. Also check that the BQ25121 is correctly connected/mounted and powered, and that pins that should be grounded is correctly grounded.