28335 eCAN listen-only

Roger Périat

Expert 2040 points

Hello,

I'm using the 28335 and I am trying to implement a eCAN listen-only mode.

The idea is to listen to the CAN bus without disturbing any (!) running communication.

In case of one special CAN message I would like to stop the listen mode and start to communicate.

Did anybody already implement something like this?

Thank you for every hint!

Regards,

Roger

Note that a initialization of the eCAN with the wrong bit rate will disturb a running communication, even if I do not send anything!

A auto-baud function for eCAN would also solve my problem...

over 12 years ago

0 Gautam Iyer over 12 years ago

Guru 192875 points

Ohh... your protocol would eavesdrop on the communication. You'll have to avoid using interrupts and use mailbox_read and mailbox_check functions.

Note that a initialization of the eCAN with the wrong bit rate will disturb a running communication, even if I do not send anything!

This happens not only with CAN but other communication protocols too :)

I've not implemented this, but seems to me like a very much possible implementation.

Good Luck.

Regards,

Gautam

0 Roger Périat over 12 years ago in reply to Gautam Iyer

Expert 2040 points

Hi Guatam,

Thank you for your response.

Unfortunately it is not the same as on other communications... The initialized CAN module on my controller will disturb a communication on the CAN bus which runs at other Bit rate. Even if I do not send anything

Example:

2 systems do communicate over the CAN bus with 500 kBit/s and then my controller boots and inits its CAN to 250 kBit/s.

The communication of the 2 partners will be disturbed, even if my controller does nothing (no TX).

I found a possibility to stay quiet with setting the CANMC.STM bit. So I do mark this thread as resolved.

Thank you anyway

Roger

0 Gautam Iyer over 12 years ago in reply to Roger Périat

Guru 192875 points

Hi Roger,

Great that you've resolved the issue. But Flexray and LIN are probably the other 2 communication protocols in which, one can disturb the other communication channel partners.

Regards,

Gautam

0 shweta PC over 11 years ago in reply to Gautam Iyer

Prodigy 40 points

Hi All,

I dont know how to start new thread so m just following here..

I am studying about FlexRay protocol.

I need help.

0 Gautam Iyer over 11 years ago in reply to shweta PC

Guru 192875 points

Hi Swetha,

All you've to do to create a new post is :

1. Go to the interested forum, like this forum is for C2000 devices

http://e2e.ti.com/support/microcontrollers/c2000/f/171.aspx

2. Click on this button to start a new thread:

Regards,

Gautam

0 shweta PC over 11 years ago in reply to Gautam Iyer

Prodigy 40 points

Thank you Gautham.

C2000™︎ microcontrollers

C2000 microcontrollers forum

28335 eCAN listen-only