Other Parts Discussed in Thread: BQSTUDIO
Dear TI-Forum users,
Recently I found out how to calibrate the voltage measurement of the BQ35100 with my own code. But calibrating the current seems a bit more difficult.
From my understanding it should be something like this:
-First, make sure in ACC mode, GE on.
-Then do the voltage calibration and then calibrate CCoffset and BoardOffset without "battery" (without current flowing).
-Then do the current calibration (I connected an electronic load to the BAT+ and PACK- connections to get 1A flowing):
- Read CCOffset from Dataflash 0x4008;
- Read Board Offset from Dataflash 0x400C;
- Obtain the avg raw current value;
- ccGain = (float) knownCurrent / (float)((int)avgRawCurrent - ( CCOffset + BoardOffset ) / 16 ;
- ccDelta = ccGain * 1193046;
- convert the float to a uint32 value and send CC Gain to 0x4000 and CC Delta to 0x4004;
For some reason, with the electric load connected the current() command gives a value of 11657mAh after calibrating. Some factor of 10 from what I'm expecting.
CCoffset = 22010;
Board Offset = -61;
CCgain is negative?: -0.79302 ==> after the float2bytes convention it changes to 7403cb80;
CCdelta = -946111.06250 ==> after the float2bytes convention it changes to ffff9080;
I have already read everything noted on this forum: https://e2e.ti.com/support/power-management/f/196/p/785441/2912877#2912877. I'm curious about the special considerations noted on this forum: https://e2e.ti.com/support/power-management/f/196/t/628425?tisearch=e2e-sitesearch&keymatch=cc%20calibration.
This is the manual I'm following for the calibration: http://www.ti.com/lit/an/slua640b/slua640b.pdf , together with the TRM.
Hopefully someone who already figured out how to calibrate the BQ35100 without bqstudio could help!
Thank you,
Jorg
