BQ76940: BQ7694002DBTR

Dharmender Singh

Part Number: BQ76940

i am using BQ7694002DBTR part which is a TI AFE without CRC. I am trying to communicate with the same using my renesas controller R5F104FCG. in the write sequence and in the read sequence i am getting ACK from the AFE in the reply on the reception of the IC , Register address and after data transmission. but whenever i tried to read the data of the reqisters i am getting only 0x00 in return no other value.

So please help me why this is happening and how to solve this issue. for reference i already attached the images of the communication.

over 4 years ago

0 Matt Sunna over 4 years ago

TI__Guru* 81034 points

Hi Dharmender,

Can I ask what sequence exactly you are trying to write and read? From the waveform it looks like you are trying to write to multiple registers (block write) and then I do not see the I2C reads? Also, what frequency are you running the I2C clock?

Regards,

Matt

0 Dharmender Singh over 4 years ago in reply to Matt Sunna

Prodigy 30 points

This is another sequence in which i am writing 5 different register locations and try to read the same after ending the write sequence. please check.

and my I2C frequency is 90KHz. and also please share what are the default values of these location.

thanks

0 Matt Sunna over 4 years ago in reply to Dharmender Singh

TI__Guru* 81034 points

Hi Dharmender,

The default values are listed in the device datasheet.

It doesn't look to me like you are doing read operations correctly. Have you looked at the datasheet waveforms to understand the protocol? Section 3.2 of this document may also be helpful: https://www.ti.com/lit/an/slva704/slva704.pdf

Best regards,

Matt

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BQ76940: BQ7694002DBTR