Setting up CAN interface for Xilinx ZCU102

CAN won't transmit anything if there isn't anything to receive the messages.

Can you post a sketch of your test setup.

So,

1: a HOST pc (ubuntu)

2: Waveshare USB CAN to PC adapter (Tested, Working)

3: Xilinx ZCU102 ultrascale board

USB CAN is connected to the Host PC, Other side PINs (CAN_L CAN_H and GND) are connected to zcu102 board on J98.

Also, Petalinux 2022.2 built with CAN enabled.

Hi michaelkellett Do you have any leads on this?

You need to provide more info,

Tell us how the Waveshare is set up. If it has its own software then use that rather than your own Python script. I've not used a Waveshare but CAN adapters often come with some basic software that allows you to set things up, tx/rx basic messages and gives diagnostics.

connect a scope channel to each of CAN_H, CAN_L and show us what you see.

CAN uses several different hardware standards and buses need to be terminated and biased correctly.

If you have access to a working CAN device that will talk to the Waveshare that will prove that you are driving it correctly.

MK

I have tested both, software of waveshare as well as SocketCAN script using. I can see transmitted data on the oscilloscope.
The problem is, when i do the same from the board. I dont see anything on the oscilloscope.

e.g. I send data using (cansend can0 123#1234) from the board. I dont receive on the host using (candump can0). Also when i send from host, i dont receive anything on the board.

While in the loopback operation (on both) i receive data. Which assures me that drivers are fine.

Usually you need to set up CAN to receive and acknowledge messages. If you don't then the bus will stall very quickly.

Loopbacks are deceiving in that they don't test the hardware connection.

MK

Actually thats what i was looking for at the beginning, any guide or tutorial in which it describes how to set up CAN for this specific board. Documentation provided by Xilinx do not contain any information on how to set up CAN.

I am new to CAN interface. Lacking even the basic knowledge here. Just wanted to perform a small test to check if i am possible to maintain data through CAN.

You have my sympathy.

I've never done CAN with an FPGA but always with microprocessors.

Your best bet with X is to find an example.

I found this which was promising:

https://adaptivesupport.amd.com/s/question/0D54U00006ao0dESAQ/what-is-the-proper-way-to-calculate-the-can-bus-bittiming-values-for-the-zcu102?language=en_US

Until I saw that AMD never answered !

But the question may help you a little.

But if your CAN tool never sends to the board at all that looks like a hardware set up thing.

You can see from the question above that the PCAN tools help with some diagnostics  - I've spent quite  a bit of time looking at the BUS-HEAVY message !

In order to learn enough about CAN you may need to play with some kind of micro based CAN boards.

Your board does have jumpers for CAN termination - it would be worth checking for documentation on them.

MK

Thank you michaelkellett 

I will follow this and will see if i get something.