Connecting nRF52832 and TI BQ27441-G1: an issue with I2C

[SKR]

Hi!

I'm using nRF52832 dev board and lastest SDK to connect with a battery babysitter (Sparkfun dev board). The latter uses TI BQ27441-G1 fuel gauge; its configuration can be reached via I2C. 

The issue is that half the time the fuel gauge doesn't respond to commands as there is no ACK returned. On logic analyser I always see nRF outputing SDA and SCL signals, but sometimes there is no ACK, even though nothing has changes electrically, or in the code. For example, when using the TWI Scanner example, the gauge's address is sometimes found and sometimes it isn't.

I know the issue is more likely to be on the fuel gauge side, but I would like to make sure that I'm doing everything right on the Nordic's side of things.

Here are the questions:

1.) Is there anything I do to confirm the I2C master on the nRF52 is working correctly? So far, I've tried different input voltages, different pins for SDA and SCL, different clock frequencies, but the results are always the same.

2.) Is there, by chance, any reported implementation of the BQ27441-G1 fuel gauge on the nRF?

[Dmitry]

Hi,

we have used another gauge model (BQ27621) with similar interface. The chip has very low-power internal logic with some limitations - you have to insert a 66-us pause between commands, the host should issue no more than two commands per second, sequential reads are supported only at frequencies up to 100kHz (I would say, it's better not to try higher ones at all).

A logic analyzer trace would help much.