BQ40Z80: Accessing different registers

Ankur Aggarwal

Part Number: BQ40Z80

Hello,

My team is using the BQ40Z80 as a fuel gauge. When I probe for manufacturer info (0x20), I get a clear Ack and proper response as shown. However, I don't get the same response when I query 0x71, which contains the DAStatus that I'm interested in for Cell Voltages 1-4. Instead, I get a NAK

Alternatively, is there an easier way to obtain those cell voltages?

Best Regards,

Ankur Aggarwal

over 2 years ago

0 Shirish over 2 years ago

TI__Guru 57697 points

Hello Ankur,

Manufacturer name 0x20 is a direct command whereas DA Status is a manufacturer access command.

See TRM section 18.1 0x00 ManufacturerAccess() and 0x44 ManufacturerBlockAccess()

This will apply to read DAStatus regosters

0 Ankur Aggarwal over 2 years ago in reply to Shirish

Prodigy 50 points

Hi Shirish,

I'm trying ManufacturerAccess() as it appears to be described, and I'm not getting meaningful results. I used the Chem ID (0x0006) example in the TRM, as well as my intended DAStatus1 (0x0071). In both instances, I get the 0x20 (I assume this means 32 bytes) followed by 0x61, 0x62, 0x63...etc., in sequence, which does not make sense in either context, as shown in my logic analyzer traces.