Communication problem between s32k344 and mc33775a via mc33664 transceiver

[hbsantos]

I am using the s32k344 microcontroller and the MC33775A TPL via MC33664 transceiver. I took the example code provided by NXP in the latest SDK version SW32K3_BMS_SDK_4.4_1.0.0, but when I send a command to the MC33775A via MC33664, the MC33775 does not send any data. My application is configured as shown in the figure below and the attached code. Are there any settings that have not been adjusted correctly?

[hbsantos]

I had an evolution, analyzing the LSPI_0 signal, the SCLK_TX was 4MHz, twice the configured frequency (2MHz).

So I set the clock source of LSPI_0 (AIPS_FLAT_CLK) to 40MHz.

To perform a test, I am sending the wakeup command continuously and viewing the signals from the master SPI and the slave SPI, as shown in the figure below.

But I'm still having trouble getting any response from MC33775A.

[JozefKozon]

Dear H.B. Santos,

please confirm, that you have followed the Installation Guide below. Please note, that the HVBMS example is not compatible with the S32DS IDE v3.5 only with S32DS IDE v3.4. If you haven't followed the instruction in the Installation Guide, please delete the S32DS IDE and start from the scratch again.

Please download the ug763620 "HVBMS Software Installation Guide". 

It is very important to follow the steps in the in the "Installation Guide". As the first step must be installed the S32DS IDE. Please uninstall the S32DS IDE, then install it again and please follow the procedure. If you will not follow the install order, even if you install everything, the HVBMS software bundle will not work.

https://community.nxp.com/t5/S32K/HVBMS-bring-up-example-build-problem/td-p/1650994

With Best Regards,

Jozef

[hbsantos]

Dear Jozef,

I followed the installation sequence provided by the HVBMS Software Installation Guide. Before, I identified that the SPI clock was twice what it should be. I fixed this by adjusting the AIPS_FLAT_CLK clock to 40MHz as demonstrated in my previous reply.

I have updated to the latest version of the BMS SDK, but the MC33775 still does not send a response to the microcontroller. Investigating the MC33775 board, I found that the VDDC input was not reaching the minimum operating voltage, so I added an external 5V supply. From this change, the MC33775 started to operate in 300ms (timeout), but still does not send a response. Would the MC33775 work if the VBAT was powered with 12Vdc and the VDDC input with 5Vdc?

Best regards,

Higor.

[hbsantos · Accepted solution]

Dear Jozef,

I powered the VBAT with 12Vdc and VDDC with 5Vdc and the MC33775 worked perfectly.

Best regards,

Higor.