TCAN4550: Sending and Reading CAN messages

Hi Naveen,

The link you provided to the e2e post you took the linux code from appears to be broken.  When I try to pullup that link I get a message stating:

Hi Jonathan,

Thanks for the quick response.

Here is the link for the thread

Thanks!

Naveen

Hi Naveen,

I would like to clarify my understanding because I have a couple of questions.

1. Are you creating a bare-metal application based on the example code you have referenced, or are you trying to use a Linux based application?  The code you have referenced is for a bare-metal application typically used with a non-Linux MCU, but you have also mentioned that you are using a Linux driver.  There is an official Linux driver adopted and supported in the Linux Kernel so I want to make sure I understand what you are trying to accomplish.  At the moment I am assuming that you have a Linux environment and are trying to create some bare-metal code to interface with the TCAN4550 in a form of hybrid system.  This is fine, but I just need to understand the goal.
2. When you mention "CAN message is been transmitted continuously," does that mean that you are issuing the transmit command continuously, or is the transmitting board continuously transmitting the same message after only a single write command from the processor?  If the device is transmitting repeatedly on its own based on a single write command from the processor, then this is an indication the receive board has not "acknowledged" the message on the CAN bus and the transmitting board is simply following the CAN protocol of automatically re-transmitting the message again until it is acknowledged.  You can disable the automatic re-transmission feature with the DAR bit in the CCCR register.  But this could indicate the receiving board is not configured properly, or there is a hardware/schematic issue with the bus that is causing the signal to not be received properly.
3. To help me better debug your communication issue, can you share with me the TCAN4550 portions of the schematics so that I can review them for errors or adjustments?  If you can share them in the forum that is great, but if you would prefer to keep them off the forum just let me know and I can send you an email. 
4. Can you also share with me your configuration settings for the TCAN4550 devices?  What is the clock frequency, Nominal and Data Bit Timing settings, etc.

Generally speaking, if your receiving TCAN4550 device is configured with the proper bit timings, then it will acknowledge any message on the CAN bus regardless of whether the processor is reading the incoming message from the RX Buffer/FIFO.  So we need to ensure that both the TX and RX devices are configured for the same settings, there is the proper CAN bus termination of 120 ohms at each end of the wiring harness, the clock frequencies are the same (typically 20Mhz or 40Mhz for CAN applications), the Vsup and Vio supply voltages are correct, etc. 

Regards,

Jonathan

Hi Jonathan, 

Thanks for your detailed queries.

My replies below:

1. We have created our own linux driver and imported all the functions from msp430 demo code...like Init_CAN , writing to tx buf ID 0x144 and reading from rx_buf

2. We are transmitting only once and seeing continuous retransmission
3. I would prefer to share our codes and schematics over mail to you. This is my email: <Removed for privacy>
4. We are using the same settings as in demo software. We would be sharing our codes over mail for your review.

Regards,

Naveen