Multiple MC33772B in TPL configuration

[Lex1]

Hi, I have been trying to get the Monitoring_Diagnostics software to work with multiple MC33772B's.
I have been using the S32K144 with the FRDM33664 and TPL to communicate to the MC33772B's.
But when I try to change the amount of devices I get a communication error: 'An error occurred during BCC initialization: (0x0004)' and I am unable to figure-out how to fix this.
This error does not happen when the device count is 1.
I have also tried to reassign CID's with the use of the soft_reset, but after changing the first one to CID 2 I am unable to find another with the CID 0 or 1.

Thanks.

Lex

[JozefKozon]

Hi Lex,

please make sure, that you have the MC33772B components with TPL communication option. They should have the letter T in their part number. The components with S in their part number cannot communicate via TPL interface. Please see examples below.

MC33772BSA1AE-only SPI interface.

MC33772BTA1AE-TPL interface or SPI interface.

Have you created your own design or are you using our Evaluation boards. Please share your schematic with voltage levels and part values if you have created your own design. If you are using our EVBs, please share the full board numbers of all EVBs you are using.

With Best Regards,

Jozef

[Lex1]

Hi, I have made sure that the MC33772B are the MC33772BTA1AE variant.
The EVB's that we are using are: S32K144EVB-Q100 and the FRDM33664BEVB.
We don't use an EVB for the MC33772B and the schematic that we use is shown in the figure below.

Because we are able to communicate with the first node in the chain the cell voltages are shown below together with the voltage of the TPL connection.

Thanks.

Lex

[JozefKozon]

Hi Lex,

please refer to the section 11.1.1 in the MC33772B datasheet. You need to initialize each node with a new CID value. After power-up you need to write to the first node with CID equal to 0000, program it with a new CID. This way the first node is initialized. Then you need to close the bus switch writing to the INIT[BUS_SWITCH]. Now you need to initialize the second node with new CID same way as the first node. 

With Best Regards,

Jozef

[Lex1]

Hi, I am now able to reassign the CID and close the bus switch.
I then use the startApp function but it stops after reading the GUID and the GUID reads all zero's, when before it had an actual number/letter sequence.

Thanks.

Lex

[JozefKozon]

Hi Lex,

thank you for letting me know. Is the communication working correctly now? I couldn't find the meaning of the GUID in the MC33772B datasheet.

With Best Regards,

Jozef

[Lex1]

Hi, The GUID is a unique serial number hard-coded in every MC33772B chip by NXP and is unchangeable as far as I know.
There is a function called "BCC GUID Read" in the PG_BCC (Battery Cell Controller Software Driver
v1.1 (Full))
And I use this to make sure I have a connection with the different MC33772B chip's.

Thanks.

Lex