BQ27542-G1: BQ27542-G1

Mark Mendelsohn

Part Number: BQ27542-G1
Other Parts Discussed in Thread: BQSTUDIO

That Data Flash for Subclass 81 (Gas Gauging, Current Thresholds) can be read correctly and the calculated checksum matches the checksum value stored.

Subclass 48 (Configuration, Data) is offset by 1 byte when read and the checksum does not match. Even after adjusted for the missed first byte, the calculated

checksum still does not match.

Fullscreen class81.txt Download

 0> DBG1> 0: 0x00
 0> DBG1> 1: 0x3c
 0> DBG1> 2: 0x00
 0> DBG1> 3: 0x4b
 0> DBG1> 4: 0x00
 0> DBG1> 5: 0x28
 0> DBG1> 6: 0x00
 0> DBG1> 7: 0x3c
 0> DBG1> 8: 0x3c
 0> DBG1> 9: 0x01
 0> DBG1> 10: 0x90
 0> DBG1> 11: 0x00
 0> DBG1> 12: 0x00
 0> DBG1> 13: 0x00
 0> DBG1> 14: 0x00
 0> DBG1> 15: 0x00
 0> DBG1> 16: 0x00
 0> DBG1> 17: 0x00
 0> DBG1> 18: 0x00
 0> DBG1> 19: 0x00
 0> DBG1> 20: 0x00
 0> DBG1> 21: 0x00
 0> DBG1> 22: 0x00
 0> DBG1> 23: 0x00
 0> DBG1> 24: 0x00
 0> DBG1> 25: 0x00
 0> DBG1> 26: 0x00
 0> DBG1> 27: 0x00
 0> DBG1> 28: 0x00
 0> DBG1> 29: 0x00
 0> DBG1> 30: 0x00
 0> DBG1> 31: 0x00

Fullscreen class48.txt Download

0> DBG1> Reading 32
 0> DBG1> 0: 0xd8
 0> DBG1> 1: 0x00
 0> DBG1> 2: 0x31
 0> DBG1> 3: 0x00
 0> DBG1> 4: 0x00
 0> DBG1> 5: 0x00
 0> DBG1> 6: 0x01
 0> DBG1> 7: 0x00
 0> DBG1> 8: 0x05
 0> DBG1> 9: 0x03
 0> DBG1> 10: 0x84
 0> DBG1> 11: 0x03
 0> DBG1> 12: 0xe8
 0> DBG1> 13: 0x0e
 0> DBG1> 14: 0xd8
 0> DBG1> 15: 0xfe
 0> DBG1> 16: 0x70
 0> DBG1> 17: 0x50
 0> DBG1> 18: 0x00
 0> DBG1> 19: 0x0a
 0> DBG1> 20: 0x7f
 0> DBG1> 21: 0x07
 0> DBG1> 22: 0x01
 0> DBG1> 23: 0x00
 0> DBG1> 24: 0x00
 0> DBG1> 25: 0x00
 0> DBG1> 26: 0x00
 0> DBG1> 27: 0x00
 0> DBG1> 28: 0x00
 0> DBG1> 29: 0x00
 0> DBG1> 30: 0x00
 0> DBG1> 31: 0x3b

over 5 years ago

0 Andy Liu (BMS) over 5 years ago

TI__Guru 52115 points

Hi Mark,

I would suggest you change one parameter in bqSutdio and use a logic analyzer to capture the i2c communication to see how bqStudo updates that subclass.

Andy

0 Mark Mendelsohn over 5 years ago in reply to Andy Liu (BMS)

Prodigy 70 points

listviewdevkitall.csv listviewfromispfixed.csvAndy,

Attached are two I2C traces,. One from the BMS dev kit and one from our ISP. Both are issuing the same command sequence, but the ISP is always missing the first byte of the 32 byte read for Configuration/Data subclass. This does not happen when reading the Gas Gauging/Current Threshold subclass. HW and FW Versions of both devices match.

0 Andy Liu (BMS) over 5 years ago in reply to Mark Mendelsohn

TI__Guru 52115 points

It seems like there should be something wrong with your ISP. Is this ISP something like a microcontroller?

Andy

0 Mark Mendelsohn over 5 years ago in reply to Andy Liu (BMS)

Prodigy 70 points

Its a board with an ARM processor on it and the TI BMS. But regardless of that, the analyzer on the I2C is showing

the same interaction, except for missing the first byte on the one particular subclass. Other subclass read OK.

That seems to me to mean the TI BMS has different behavior depending on which 32 byte subclass gets read.

0 Andy Liu (BMS) over 5 years ago in reply to Mark Mendelsohn

TI__Guru 52115 points

I don't think the firmware code will handle that particular subclass differently. Can you see the same issue if you use the Advanced Comm I2C in the bqStudio?

Andy

0 Mark Mendelsohn over 5 years ago in reply to Andy Liu (BMS)

Prodigy 70 points

The same issue does not exist using the studio.

I got around it by shifting the data that was read by one byte. Inserting the missing byte in the front of the buffer.

Writing the modified data and the newly calculated CRC.

Power management

Power management forum

BQ27542-G1: BQ27542-G1