UJA1169 TRANSCEIVER

[hajianik]

Hi ,

I'm trying to run the project example FlexCAN on the S32K DESIGN STUDIO with no success.

I suspect the culprit is UJA1169 Transceiver. This project originally uses a different Transceiver.

However I modified it to use the UJA1169 .

But it is not working for me .

I 'm pretty certain that I connected the boards and all the jumpers are set properly however I'm not a %100 sure.

CAN_HI/LO to CAN_HI/LO and Ground to Ground  and jumpers j109/j108 are at default 1-2 position to insert the termination. THE BOARDS ARE POWERED VIA micro USB connector .

But I can't see anything on the scope on TX/RX CAN_HI/CAN_LO and it is not toggling the LEDS as it is supposed to.

When I choose the loop back mode for the CAN, it works

The project is attached.

Thanks,

Koorosh Hajiani

Original Attachment has been moved to: FlexCAN.zip

[robertboys]

Here is a CAN prime that is easy to understand:  It explains several "gotchas" that catch many.....including no ACK bit.

Page 4 shows a "cheat" you can use to connect two controllers that do not have transceivers.

http://www.keil.com/appnotes/files/apnt_247.pdf 

Bob

[hajianik]

This is very helpful.

Thanks,

Koorosh Hajiani

[hajianik]

I believe the Can controller keeps sending the frame until another node would acknowledge it by pulling the bus low for 1 bit time.

[danielmartynek]

Hi,

The UJA1169 Transceiver needs 12V power supply.

Regards,

Daniel

[hajianik]

Hi Daniel,

I just found that out last night.

Do I really need to initialize this transceiver. On the power up it resets and coming out of reset it goes in Normal mode or standby mode.

I don't need the regulator nor the watchdog feature of this. so do I really need to send bunch of SPI frame to initialize it when I just need the CAN transceiver?

One more thing , I only have power supply for one board currently ,so only one board is  running and yet I see activities on the TX_CAN line continuously, when I send the CAN frame only once, IS IT BECAUSE AS LONG AS THIS FRAME IS NOT ACKED BY A RECEIVING NODE.

TRANSMITTING NODE KEEPS SENDING IT ? OR THESE ARE JUST ERROR FRAMES? and why continuous?

I don't have a CAN tool, just a scope.

Thanks,

Koorosh Hajiani 

[razva_tilimpea]

Hi,

When the board is delivered the SBC is in Forced normal mode and the CAN transceiver is enabled. You can skip SBC initialization if you need only the the CAN transceiver. For more details about this mode please check this http://www.nxp.com/docs/en/data-sheet/UJA1169.pdf , chapter 7.1.1.7.

Best regards,

Razvan

[danielmartynek]

Hi,

I'm not familiar with the SBC. But you can use the SDK driver for UJA1169 and configure everything you need.

Regards,

Daniel