Part Number:BQ34Z100-G1
I just spent a long time trying to configure a BQ34Z100-G1 gas gauge by changing a few parameters, e.g. Voltage Divider and CC Gain. Whatever value I entered, it reported "A read of data written failed comparison". I tried sending the UNSEAL and UNSEAL_FULL_ACCESS commands first, and of course switching everything off and back on. Always I got the same report.
In frustration I tried a second board, which as far as I know is identical to the first. It worked first time! These are both brand new parts from the same batch and the boards have had full anti-static precautions taken. The circuit is of my own design, but apart from different component values for my specific battery, is copied from Texas Instruments example schematic. My configuration tool is Battery Management Studio (bqStudio) 1.3.54.1. I'm hoping this isn't a chip failure which would not bode at all well for production: I'm assuming it's some sort of configuration problem.
Can anyone suggest why one chip works and another doesn't? Is there anything I should / should not have done, or can someone suggest how to diagnose the problem please? Thanks for any help.
For information, I've attached a csv capture of the bad I2C data. It's split into two bursts because my 'scope doesn't have sufficient record length / resolution to capture it all in one hit.
| FIRST BURST OF DATA: | |||||
| Tektronix MSO2024B, version v1.56, serial number C021227 | |||||
| Bus Definition: I2C | |||||
| Time | Repeat Start | Direction | Address | Data | Missing Ack |
| -4.00E-06 | Write | AA | 61 00 | ||
| 1.60E-02 | Write | AA | 3E 68 | ||
| 3.20E-02 | Write | AA | 3F 00 | ||
| 6.36E-02 | Write | AA | 40 7F 71 27 D4 94 08 99 F9 FB 50 00 00 00 00 82 64 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ||
| 7.80E-02 | Write | AA | 60 B5 | ||
| SECOND BURST OF DATA: | |||||
| Tektronix MSO2024B, version v1.56, serial number C021227 | |||||
| Bus Definition: I2C | |||||
| Time | Repeat Start | Direction | Address | Data | Missing Ack |
| -4.00E-06 | Write | AA | 61 00 | ||
| 1.50E-02 | Write | AA | 3E 68 | ||
| 3.10E-02 | Write | AA | 3F 00 | ||
| 6.20E-02 | Write | AA | 40 | ||
| 6.23E-02 | X | Read | AB | 7F 71 27 D4 94 08 99 F9 FB 50 00 00 00 00 13 88 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | |
| 7.90E-02 | Write | AA | 60 | ||
| 7.93E-02 | X | Read | AB | 0 | |