This is just an information: In case anybody is experiencing random i2c shifts when reading bytes it may be due to an issues by the hardware timing on the nrf52840: https://devzone.nordicsemi.com/f/nordic-q-a/48166/i2c-clock-stretching-on-nrf52840
Hopefully this pull will fix it: https://github.com/particle-iot/nrf5_sdk/pull/9
Interesting find 
Could you add this info to that issue and/or open a separate issue?
This issues still persist on bsom devices which makes them not usable with i2c devices that do clock stretching (Battery managements for example). Are there any plans to move to an nrf chip which doesn’t suffer from such basic issues?
@lympik Did you ever get the Argon communicating with the BQ40z50 via Clock Streching?
I’m working with the same chip and the I2C hangs when it worked just fine on a Photon.
Do I need to add the Clock streching command on the Argon?
Was the 
Clock Streching command added for the Gen3 line specifically?
You need to enable 400khz in bq studio. Don’t know if this is present in BQ40z50
Sweet! I’m using the BQ4050 so that should work.
