S32K312 FLEXCAN1 is not working

[vinaychitturi]

Hello,

I am using the s32k312 evaluation board for my testing, On that board i configured two flexcan's Flexcan0 and flexcan1.

For the flexcan0 testing i am using the ports PTA6 AND PTA7 and it is working completely fine. I am able to receive the messages and transmit the messages.

But the flexcan1 is not working. I am trying to send the dummy data on flexcan1 but i am seeing nothing on that ports(PTC8) . Currently for flexcan1 i am using ptc8 and PTC9. To use those two ports for the flexcan1, I need to remove the resistors R461 AND R157 which are connected to the FS26 in the evaluation board to use for the flexcan1.

Can you please share any sample or example project where this flexcan1 is used?

Thanks in advance

[vinaychitturi]

Hello, 

Thanks for the reply.

I tried to test this can1 on evaluation board by connecting the external can transceiver but still I am not seeing any communication at the transceiver end. In our production board we connected the can1 to sbc transceiver and I enabled the can in sbc through spi but still I am not seeing any communication on production board also.

Can you please verify if i did the configuration for the flexcan1 properly? 

Thanks in advance

[Senlent]

Hi@vinaychitturi

I test your project and i can receive frame from CAN1.

Senlent_0-1726733504888.png

[vinaychitturi]

Hello,

Thanks for the quick reply and for your testing.

So you did this testing by connecting a external can transceiver from can1 then you are able to see this can frame.

Because from my end after connecting the can transceiver or sbc after sending an message from flexcan1 that mb is always staying bus is busy, once the tx is sent we should change back to idle state through the flexcanirq_txmbinterrupt.

But in my end I never hit any breakpoints for the tx or rx mb interrupts.

Have you seen this kind of behaviour before or Is there anything I am missing while testing?

Thanks in advance.

[Senlent]

Hi@vinaychitturi

This may still be related to your FlexCAN1 hardware connection.

I did not test FLEXCAN1 on S32K312EVB. As I said, the hardware of S32K312EVB does not allow you to evaluate FlexCAN1.

I have special hardware to evaluate your code.

[vinaychitturi]

Hello,

Thanks for your reply.

I am doing few testing's from my end on evaluation board to make sure MCU is transmitting properly because we are still not seeing any CAN messages on the CAN1 channel on the actual production board with SBC transceiver.

For testing whether evaluation FLEXCAN1 functionality is working or not we are tried few things

1) I enabled the loop back mode for the flexcan1, so that without the can transceiver also I need to receive the data back from the flexcan1 ( It will send and receive the messages internal to the can1 controller). In this testing also I didn't received any data through the flexcan1.

2) I enabled can1 and can2 controllers and I am sending from can1 TX pin to Can2 RX pin directly without the can transceiver to see whether the data is being transferred from can1 and received to can2. Even in this testing also I am not seeing data from can1 to can2

If the following two methods are not the right way for testing, can you please let me know what I can do for testing the microcontroller flexcan1 without can transceiver to confirm that our microcontroller is having no issues?

I am attaching the above mentioned two projects. Please let me know if I did anything wrong in the configuration.

If the above methods are proper way of testing can you please share the example code for the flexcan1 loop back mode using interrupt and transferring the data for  flexcan1 to flexcan2 using interrupts.

Thanks in advance.

[Senlent]

Hi@vinaychitturi

Made some change base the demo " Flexcan1_loopbackmode.zip"

test result.

Senlent_0-1727087343480.png

I'm sorry that I couldn't upload the complete project to you after trying several times.

I uploaded the configuration file and the modified main.c only.

[vinaychitturi]

Hello,

Thanks for your support and for the changes for the loop back mode.

I forgot to add the hardware object for the can1 Rx, But with your changes loop back mode for the flexcan1 testing it is working good.

Regarding the second test i mentioned in my previous comment, I added the hardware object for receiving the message for can2. In that test, From hardware side i connected CAN1TX(ptb22) to can2RX(ptc16). i am sending the message from can1 TX(PTB22) to the can2RX pin(PTC16). In this test i am unable to see any messages from can1 to can2 without can transceiver.  I am attaching the updated project as mentioned above.

Is it a feasible test to verify the flexcan1 from the MCU side.

Thanks in advance

[Senlent]

Hi@vinaychitturi

This method doesn't work, please don't waste your time on it.

[vinaychitturi · Accepted solution]

Hello @Senlent,
Thanks for your support and information

[vinaychitturi]

I am attaching the project i am using for testing the flexcan0 and flexcan1. In that example i am sending dummy messages for both CAN's. But i am seeing those messages only from the CAN0( PTA7). I am attaching the screenshot i am seeing when running this sample project

flexcan.PNG

In the above screenshot channel5 corresponds to the data I am sending through CAN0-TX(PTA7), Channel4 corresponds to CAN1TX(ptc8). 

Please let me know, If I configure something wrong for the FLEXCAN1.

[Senlent]

Hi@vinaychitturi

You need to note that CAN1 is not used on the S32K312EVB hardware.

If you need to use the evaluation CAN1 instance, it needs to be supported by additional CAN

transceiver hardware. This may be the reason why you cannot measure the CAN1 signal.