BMS & MBDT - RDDRONE-BMS772 MC33772B / S32K144 SPI COMMUNICATION FAULTS

[OGUZ1]

Hi,

We try to communicate between MCU(S32K144 - 48Package) and MC33772B on board RDDRONE-BMS772 by using matlab simulink. 

First of all, we changed the oscillator on the board with an 8 MHz oscillator, since we couldn't select the Matlab Simulink "XTAL clock" value of 32 MHz.

Then we fed our board with a 6S battery pack (20.41Volt).  Since we wanted to measure 6 cells, we made the pin connections. Then, we set the mosfets, we got 20.41 volts from the output of the card.

We connected a 24 Volt 0.15A fan to the output of the card. There are differences between the values we get and the values we see in FreeMaster.

The cell voltage values we measured;
Cell_[0] : 3.391V
Cell_[1] : 3.405V
Cell_[2] : 3.406V
Cell_[3] : 3.407V
Cell_[4] : 3.406V
Cell_[5] : 3.399V

The Isense CURRENT value we measured; 120mA

Question 1) Why are the values of Cell Voltage lower than the real value in FreeMaster?? Especially ISENSE_CURRENT??

Question 2) How do I fix these fault values? (HardwareFault values) ??

Question 3) When we send 0 value from Matlab simulink to the gate of the mosfet, we still measured 20.41 volts at the output. After some time (about 30 minutes), the output voltage dropped to 0. Why doesn't it drop to 0 instantly?

Oguz

Regards

@mariuslucianand 

[OGUZ1]

@mariuslucianand 

Hi,

Are there any results?

[RoggeJ]

Thanks for the information, I will try to figure it out for more. Keep sharing such informative post keep suggesting such post.

[OGUZ1]

Hi @mariuslucianand ,

I want to use CAN communication but I still can't get 5V from SBC. I still could not get 5V output from SBC. Are you interested in me?

I'm using UJA1169 configuration and SPI0 but I can't see any effect. I always read something like 2.7Volt from pin V2. I always read 3.3 volts from V1 pin. I still read the same values when I press the reset button. I couldn't figure out what it means. I tried all the configurations. Vbat and Wake pins are the same value in SBC.
When I press reset, the Wake pin drops to 0. 3.3 volts is always going to the SBCWake pin of the processor.

@mariuslucianand 

Best Regards!

[OGUZ1]

@

@mariuslucianand 

Hi,

Are there any results?

[mariuslucianand]

Hello @OGUZ1 ,

It's really impressive to see your work using our MBDT!

Regarding the clock configuration, there is a way in which the files for generating code can be configured to work with the crystal oscillator of 32MHz, in a similar manner presented here: https://community.nxp.com/t5/Model-Based-Design-Toolbox-MBDT/Clock-Configuration-of-MPC5744P-using-M... But for now, if you've changed the crystal on the board, let's focus on the data acquisition correctness for the analog front end.

For the ISENSE current, I had a look at the board schematic, and I've seen that the Shunt Resistor is a physical 0.5mOhm resistor, so please make sure that this value is correctly typed inside the configuration block under the "Pack Settings" tab.

For the fault values, you can try resetting them into the controller using the MC3377xB_Fault_Clear_Status.

For the correctness of the values, can you describe the connections you performed? I am interested about POWER IN, and CT6..1.

Hope this helps,

Marius

[OGUZ1]

Hi,  @mariuslucianand 

Thanks, we adjusted the Shunt value and the value we measured was the same as the value in freemaster.
We used the ClearFault block as shown in the figure.

We only connected a 6S battery to the card. We made the jumper configuration of our board as shown in the schematic. Total battery voltage is 21 volts. Each of our cells is maximum 3.4Volt - minimum 2.9Volt. We have written  the cell voltages we measured by multimeter . At the same time, there is a value difference of factor:0.01 about 10mV.

I have a few more question...

Question 1 -) When we make the mosfet gate gate "0" by MBDT at the output of the card, why do we still get the value at the output (same as 20 volt input.)

Question 2 -) Do you have any examples for using the screen on the card?