BQ34110: I2C Communication read bytes

Gehad Elkot

Intellectual 400 points

Part Number: BQ34110
Other Parts Discussed in Thread: EV2400, BQSTUDIO

According to application note SLUA790 it indicates that when reading command data 0X08 it responds with 2bytes data

but in actual test for this command and any similar commands it responds with 3 bytes data .

can you explain this result, pleas?

over 4 years ago

0 Wyatt Keller over 4 years ago

TI__Guru** 105800 points

Hello Gehad,

What was the voltage you are trying to read? Are you getting the correct value assuming the last byte is redundant? Are you seeing it every time you send the command? Is this with bqStudio and an EV2400?

Sincerely,

Wyatt Keller

0 Gehad Elkot over 4 years ago in reply to Wyatt Keller

Intellectual 400 points

I'm trying to read battery voltage it is 14.2v Li-Ion pack battery .

No it isn't correct ; expected 443mv and getting : 377 mv after Hardware voltage divider

yes i found this every time and with other commands

i use my own hardware not evaluation board and this capture from logic analyzer display.

..........

i note that i can't access data flash memory i tried to write required address in ManufacturerAccessControl()
then read it .the reading value is 0x0000.

why i receive 3 bytes ? and what is the correct number of bytes should i receive?

0 Wyatt Keller over 4 years ago in reply to Gehad Elkot

TI__Guru** 105800 points

Hello Gehad,

Are you able to check with the TI toolchain using EVM, EV2400, and bqStudio to see if you are getting the same issues?

You should only receive 2 bytes back, Sometimes a 3rd byte will be present but the first 2 are the only ones with relevant information. I attached an example from another similar gauge. I suspect it may be a hardware issue or host MCU firmware issue.

Sincerely,

Wyatt Keller

0 Gehad Elkot over 4 years ago in reply to Wyatt Keller

Intellectual 400 points

Hello Wyatt,

can you suggest HW scenarios that may cause this problem.

Sincerely,

Gehad

0 Wyatt Keller over 4 years ago in reply to Gehad Elkot

TI__Guru** 105800 points

Hello Gehad,

I was thinking the voltage divider may not be correctly setup, so you're reading the voltage but it's scaled incorrectly to give you a very low voltage. There are examples in the TRM for voltage scaling.

Sincerely,

Wyatt Keller

0 Gehad Elkot over 4 years ago in reply to Wyatt Keller

Intellectual 400 points

Hello Wyatt,

i checked HW and it works well it may be firmware problem can you suggest any check for firmware may cause this problem ?

Regards,

Gehad

0 Jessica H. over 4 years ago in reply to Gehad Elkot

TI__Genius 11535 points

Hi Gehad,

Were you able to check with the TI toolchain using EVM, EV2400, and bqStudio as Wyatt suggested to see if you are getting the same issues? Can you walk me through how you are using ManufacturerAccessControl() and writing and reading from the device?

Power management

Power management forum

BQ34110: I2C Communication read bytes