BQ76905EVM: Seal to Full Access the device

Hi Pranav,

When sending the Fullaccess keys to unseal the device, you write the keys directly to 3E/3F and you do not send a checksum for them.

Regards,

Max Verboncoeur

Thank you for the reply

For the command sequence above, the device is not unsealed. The sequences attempting to unseal it are as follows:

1st Sequence:

1. W: 10 3e 30 00 /* Seal the Device */
2. W: 10 3e 14 04 /* Unseal the Device */
3. W: 10 3e 72 36

2nd Sequence:

1. W: 10 3e 30 00 /* Seal the Device */
2. W: 10 3e 14 04 /* Unseal the Device */
3. W: 10 3e 72 36
4. W: 10 3f 14 04
5. W: 10 3f 72 36

Still device is in Sealed State in battery status.

Hi Pranav,

You do not need a separate pair of commands to write the keys to 3F. The command [W: 10 3E 14 04] will write 0x14 to address 3E, and 0x04 to address 3F.

The first sequence should work, the second sequence may not work if the keys are being overwritten before the device checks them.

Also make sure to refresh the registers page after sending the command to update the readout.

One thing to note, I tested the sequence I sent before on an EVM and it works as expected, so if the first sequence is not working, you may want to check the communications with a logic analyzer.

Regards,

Max Verboncoeur