Problems using CAN PAL for S32K144W

[fhoetzinger]

Hello everyone,

I am using S32K144W to communicate via CAN using the CAN PAL in S32 SDK and the S32 Configuration Tools in S32DS. So far i tried to send a message based on the can_pal_s32K144w example project. However when i try to measure the signal on the Tx Pin i get wrong frames:

This is the code i used:

 Best regards.

[Julián_AragónM]

Hi @fhoetzinger,

I can see the signal from after the transceiver just fine:

Are you measuring j109.7 & j109.8? Also, I can see you've modified the nominal and data bitrate. The example configures it by default to 500kbps and 1 Mbps. By your picture, I believe it is configured for 500kbps both nominal and data bitrate, correct? 

Make sure that both the EVB and your CAN analyzer tool are set to the same bitrate and sampling point.

Best regards,
Julián

[fhoetzinger]

Hi @Julián_AragónM ,

apologies for replying so late, as i did not have the EVB at hand. The measurements were made on a custom board at the TX pin directly, so before the transceiver.

I tried modifying the CAN_PAL example to use CAN1 on Pins PTC6 and PTC7 (which are the ones used on the custom board) and ran it on the EVB.

When pushing the buttons on the unmodified program the messages are sent correctly. However with the modifications the TX Pin (PTC7, measured at J5) simply stays high now.

The only changes i did were in the Configuration Tools, the code in main.c is left unmodified.

Regards,

Fabian

[Julián_AragónM]

Hi @fhoetzinger,

In your custom board, are PTC6 & PTC7 going through a CAN transceiver? 

This sounds like a hardware issue, as the project works normally on EVB, and even on custom board when not modifying the pins. You can also compare the design with our Hardware Design Guidelines for S32K1xx. 

Best regards,
Julián