Other Parts Discussed in Thread: BQSTUDIO, EV2400
Tool/software:
Hi
After power up of my CPU, I check the ITPOR flag in the FLAGS register of the BQ27426. If this one is set, I read the CHEM_ID, what is 0x3230. Because I need another CHEM_ID, I do an UNSEAL and enter config udate mode. Then I check if CFGUPMODE ist set. With a good device, I read 0x01F9 (so CFGUPMODE ist set). Then I set the correct CHEM_ID and exit the config update mode. Then I read back the FLAGS register until CFGUPMODE flag is reset (value changes from 0x01D9 to 0x01C9). Then I make an SEAL.
In a next step, I want to write the correct parameters for the battery.
So I do an UNSEAL, enter config update mode and check if the CFGUPMODE is set. With a good device, I get 0x01D9 in this case. Then I can write the correct parameters, exit config update mode and make a SEAL.
This worked now for several devices (>30 devices).
Now I have a device that behaves different:
ITPOR is set after power up as expected, and default CHEM_ID is 0x3230, as it should be.
After the UNSEAL and entering config update mode, I get 0x47FE when reading the Flags. So there are several more bits set compared to the normal case (under-temperature, full-charge, SOC1 and SOCF). Although powering the device with the same battery as the other devices.
But because CFGUPMODE is set, I write the correct CHEM_ID, exit config update mode and make a SEAL.
But the problem is now, after a new UNSEAL and enterig config update mode, I just get 0x4FCE. So the CFGUPMODE-Flag is not set. I read this flag several times, it does not get set.
Even when doing the whole process again (UNSEAL and enter config mode) after about 10 seconds, the CFGUPMODE-Flag does not get set anymore.
The CHEM_ID got written correct, but I can't enter config update mode again to write the battery parameters.
Do you have any inputs why CFGUPMODE could not be set anymore? And why do I read flags like under-temperature, although its about 25°C?
Thank you very much, best regards
Michael
