• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 1038 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ78350 Calibration Issue

martin gibbs
Intellectual 520 points
Other Parts Discussed in Thread: BQ78350, BQSTUDIO

Hi Ti Forum,

I am having an issue with calibration of bq78350 within bqstudio.

I calibrated OK with simulated cell voltages with the resistor ladder. I have followed 6.4 of the Eval document and have now connected an 8s2p Li ion cell pack. All appears to be OK.

However:-

I am entering the average cell voltage based on the pack voltage but get a failed calibration with the red text message

"Voltage calibration - A read of data written failed comparison"

Please see attached dashboard and registers.

Thankyou for your time.

6735.bq78350 calibration issue.docx

Regards

Martin Gibbs

  • 0
    TI__Prodigy 20 points

    Martin,

    I tried this with the posted version of bqStudio under bq78350.  External Ave Voltage cal worked.    The posted version is bqStudio 1.3.24.   From the information you posted, it should work for you.   In your screen shot, the gauge is reading Ext Ave Cell Voltage of 3763mv.  You entered value of 3781mv is correct.  This is only 20mv voltage difference.   I tried +-200 mv here and was able to pull it either direction. 

    External Ave Cell voltage is enabled in Data Flash by the parameter Settings, Configuration, DA Configuration. You have this enabled since you have a valid voltage reading for ExtAveCellVotls.

    Here is what to try.  Check you bqStudio version.  This is done from "Top Menu" "About".  If your version is older than 1.3.24, download and install this bqStudio  from www.ti.com/bq78350

    If your version is the same or  later, please send the version of bqStudio your are using and information on the Eval document you are using. 

    Thanks,

    Andy Hughes

  • 0 in reply to Andy Hughes
    Intellectual 520 points

    Thanks for the prompt response.

    My bqstudio version is 1.3.24.201409161253. It is the very latest as a result of Ti solving the chemistry updater issue I had last week. See WM5295 response to me.

    The EVAL document is Literature Number: SLVU925B April 2014–Revised July 2014.

    I tried entering exactly the Ext av voltage and still got the same message.

    Is the error message  "Voltage calibration - A read of data written failed comparison" an indication of where the problem lies?

    Anyway the upshot is that after I depowered and re-programmed the firmware it then calibrated OK. 

    So I guess the question is answered. Thanks.