BQ27750: Security register values are wired.

Hi Onyx,

Thanks for the reply.

I would love to provide the bqstudio screens - but i'm not using the bqstudio, despite a fact I have bqstudio installed - it would not solve the problem. Also I'm not using standard EV3200 tool for communication as I don't have one in our lab.
My setup is next : I have cortex M4 MCU with TWI interface and BQ27750EVM-837 + logic analyser on top of TWI and some battery with load (LED + small resistor to have a higher current).

I have ported the gauge.c /.h from SLUA801 and implemented low level driver for TWI communication.
It works fine while reading - which is good, but things go wrong when I'm trying to write/configure something.
I have started investigating the root of the issue and bumped into a security bits uncertainty with "reserved" state I wrote above.

My readings for command mode look fine, but I still cant get my gauge configured (the firs thing I was thinking is a "design capacity" value update), but due to a lack of really good manual for MCU approach (If you know one - please point me) without using EV2300 tool I have stacked with this idea.
My reading's are

getManufacturerAccess:0x0C02
getAtRate:0
getAtRateTimeToEmpty:65535 min.
getTemperature:2987 x0.1K
getVoltage:3806 mV
getBatteryStatus:C0
getCurrent:-61 mA
getRemainingCapacity:2182 mAh
getFullChargeCapacity:5191 mAh
getAverageCurrent:-59 mA
getAverageTimeToEmpty:2219 x15 sec.
getAverageTimeToFull:65535 x1 min.
getStandbyCurrent:-1 mA
getStandbyTimeToEmpty:65535 min.
getMaxLoadCurrent:-500 mA
getMaxLoadTimeToEmpty:262 min.
getAveragePower:-22 mW
getInternalTemperature:2977 x0.1K
getCycleCount:0 cycles
getRelativeStateOfCharge:43 %
getStateOfHealth:97 %
getChargeVoltage:4400 mV
getChargeCurrent:4488 mA
getDesignCapacity:5300 mAh

Also I have stucked with understanding of addressing for flash values access, I have read through some e2e posts regarding flash operations but still cant understand the way of memory addressing.

If I want to access "design capacity"
Then class is "Gas Gauging"
Subclass is "Design"
and some address referred in BQ27750 RM is 0x4563 - what this hex address means ?

And what parameters should be passed to "gauge_write_data_class()" function to get access to "design capacity" value ?

I got bunch of questions, and no proper tools to figure those out end even less documentation to sort it out on my own.

Thanks for your assistance and good advice.

Kind regards,
Dmytro.

Hi Onyx,

One more update, I have successfully sealed the IC and now it replies with
CONTROL_STATUS = 0x620D - which corresponds to "sealed" state, but now I cant get the Idea how to get it usealed back.

And probably I would be able to get EV2300 soon for proper debug purpose using TI tools.
And I think I get the Idea of the right way to communicate with "design capacity" value, but I would prefer to hear you explanation if possible or super fine manual for MCU ninja's.

Thanks.
Kind regards,
Dmytro.