Other Parts Discussed in Thread: EV2400, BQSTUDIO
To control the bq40Z80, we are monitoring voltage and current data using the MCU's I2C communication.
And it sends some control commands to the bq40z80 to learn battery characteristics.
Until now, STM32F103(MCU) is successfully performing I2C communication, and I get the data I want correctly.
However, after sending the command to SEAL the bq40Z80 device, the device is deadlocked.
Among SEAL, UNSEAL, and FULL ACCESS commands, communication is cut off only in SEAL command.
In detail, if I send a command to monitor the flag status after sending the SEAL command, the CLK line goes to a low level and then does not recover.
Even after reinitializing the GPIO of the MCU's I2C line and resetting the MCU, the bq40z80 is still deadlocked.
Interesting phenomenon is that in this state, if I disconnect the communication wire with the MCU, connect the EV2400, and drive BM STUDIO, I can get the data of bq40z80 normally.
At this point, BM STUDIO indicates that bq40z80 has entered SEAL mode.
Then, if you disconnect the EV2400 and connect it to the MCU again, communication is restored and other data can be received normally.
This unknown phenomenon has been haunting me for days.
I am considering adding a bus buffer IC between MCU and bq40z80 to solve this problem.
In case someone has any experience solving similar problems like this, please share.
Best regards.
