BQ35100: can't get right current

Hi
I would recommend using hooking up bqstudio and using that as a reference to guide you on the calibration using your host.

Also, see similar posts below on calibration:

e2e.ti.com/.../2791398
e2e.ti.com/.../628425

thanks
Onyx

Hi，Onyx
I'm not sure how I store ccgain and ccdelta correctly, because the initial value in TRM is a floating point number. Could you give me the initial value in the register, please?

Such as 0x4000 3B.

And I'm very concerned about the fact that CCA can't set 1 at Board_Offset, but I can't find the reason.
thanks
Lsen Li

CC Gain and Delta are displayed as floating. It uses a special type of mantissa.

The initial value for CC Gain and Delta are found by programming the default firmware imagine on ti.com.

Are you sending the CCA command after the board boots up for calibration of CC Offset?

Board Offset is calibrated via the "Calibration" plug-in in bqStudio.

Here are my steps for cc calibration ：

1.GE = 1;

2.send Gauge_Start()(0x0011) to 0x0000;

3.send Enter_cal()(0x0081) to 0x0000;

4.send CC_offset()(0x000A) to 0x0000;

Then,I get the value of CCA is 1. Waiting for it to empty；

5.send CC_offset_save()(0x000B) to 0x0000;

Next is board calibration：

6.send Board_offset(0x0009) to 0x0000;

I can get the BCA = 1 but CCA = 0 .When I read the TRM 3.6 , BCA =1 &&CCA = 1 is the right value，but I don't know what I overlooked.

7.send Gauge_Stop()(0x0012) to 0x0000;

8.send  Exit_Cal()(0x0080) to 0x0000;

END 

Even if CCA = 0 in Board_offset(), I still get the value of Board Offset, but I'm not sure if it's true.

And I want to know the significance of Register（cc offset/AD I offset /board offset ） Value to make sure my problem.Because I found that in the TRM description, the initial values in registers do not match each other.

Such as，ccgain=0.04768 ccdelta=56774.45.BUT ccgain*1193046=56884.43

Thanks

CC Offset and Board Offset are values which are changed during the calibration procedure using the calibration plug-in. These short across SRN and SRP internally and open SRN and SRP internally when 0 current is flowing to calculate CC Offset (Short SRN-SRP) and Board Offset (Open SRN-SRP).

CC Gain and Delta have internal units. These are to reflect AvgCurrent() and Qpass() registers. CC Delta is our coulomb counter setting and CC Gain is our current measurement setting. I would just follow the calibration plug-in and use values there after selecting a sense resistor.

In this calibration process, CCA = 1 can not be obtained according to the operation specified in the figure above.