CAN COMMUNICATION

Bruno Duarte28

Other Parts Discussed in Thread: CONTROLSUITE

Hello,

I'm starting a project and i need to implement CAN communication between my LaunchpadXL F28377S and a device.

Since this is the first time working with CAN, and to better understand how it works i am trying to use one of the device examples.

While using the example can_loopback_interrupt_cpu01 i'm getting an error.

The only thing i've change on the code was the pin configuration to use the GPIO70/GPIO71 to use the launchpad transceiver.

Can someone help me to get in the right path ? I'm a bit lost ...

Thank you all.

Best Regards,

Bruno

over 9 years ago

0 Gautam Iyer over 9 years ago

Guru 192875 points

Hi Bruno,

What error do you get? Can you paste the same?

Regards,
Gautam

0 Bruno Duarte28 over 9 years ago in reply to Gautam Iyer

Intellectual 270 points

Hello Gautam,

It enters on the "if(g_bErrFlag)" condition.

If i change the pins to GPIO30 / GPIO31, as it was on the original code it doesnt show any error.

In the LaunchpadXL-F28377S overview, in the schmatics show that the CAN transciever is connected to the GPIO70/GPIO71 .

Thanks

0 Gautam Iyer over 9 years ago in reply to Bruno Duarte28

Guru 192875 points

Thats odd. Are you selecting the correct muxing scheme?

0 Hareesh Janakiraman over 9 years ago in reply to Bruno Duarte28

TI__Guru* 95315 points

Bruno,

This is strange. Are you saying if you run the original/unmodified Controlsuite example (using GPIO30/31), the example works fine, but not after you change the GPIO assignment to 70/71?

0 Bruno Duarte28 over 9 years ago in reply to Gautam Iyer

Intellectual 270 points

Hmm... It could be the problem ... but in the overview those pins are not specified on the Muxiing scheme.

I Have the following code:

GPIO_SetupPinMux(70, GPIO_MUX_CPU1, 1); //CANRXA
GPIO_SetupPinMux(71, GPIO_MUX_CPU1, 1); //CANTXA
GPIO_SetupPinOptions( 70, GPIO_INPUT, GPIO_ASYNC);
GPIO_SetupPinOptions(71, GPIO_OUTPUT, GPIO_PUSHPULL);

I'll try to search in the datasheet in the setup Pin Mux is correct and give you some feedback.

thank you

0 Bruno Duarte28 over 9 years ago in reply to Hareesh Janakiraman

Intellectual 270 points

Dear Hareesh,

Yes, Exactly.
Following the Launchpad overview, the CAN transciever pins are connected to the GPIO70/71.
When i change the base example to those pins, it enters on the error condition.

As Gautam said, it may be the SetupPinMux that may be incorrer. I'm going to try to find information on that and see if that is the problem.

Thanks

0 Christopher Chiarella over 9 years ago in reply to Bruno Duarte28

TI__Mastermind 30255 points

Bruno,

The controlSUITE examples are setup for controlCARDs, the F28377S Launchpad has a different external oscillator clock. Go into the project properties->Build->C2000 Compiler->Advanced Options->Predefined Symbols and add "_LAUNCHXL_F28377S". This will make sure your system clock is being setup correctly, otherwise you will be running at 100Mhz and not 200Mhz.

Best Regards
Chris

0 Bruno Duarte28 over 9 years ago in reply to Christopher Chiarella

Intellectual 270 points

Dear Christopher,

Thank you for the advice. I'll change that.

Best Regards,
Bruno Duarte

0 Christopher Chiarella over 9 years ago in reply to Bruno Duarte28

TI__Mastermind 30255 points

*edited*

Bruno,

After reviewing further, I believe your muxing is incorrect.

The peripheral mux selection value should be 5.

GPIO_SetupPinMux(70, GPIO_MUX_CPU1, 5); //CANRXA

GPIO_SetupPinMux(71, GPIO_MUX_CPU1, 5); //CANTXA

GPIO_SetupPinOptions( 70, GPIO_INPUT, GPIO_ASYNC);

GPIO_SetupPinOptions(71, GPIO_OUTPUT, GPIO_PUSHPULL);

Best Regards

Chris

0 Bruno Duarte28 over 9 years ago in reply to Christopher Chiarella

Intellectual 270 points

Thank you Christopher,

I've Corrected that and it seems to be sending something on the pins connected to the transciever.

Just need to check on the CAN side of the transciever if it shows the data being send.

Thanks,

Best Regards,
Bruno

0 Bruno Duarte28 over 9 years ago in reply to Bruno Duarte28

Intellectual 270 points

Dear Christopher,

I've implemented the communication from CANA to CANB and it works fine,

Thank you all.

Bruno

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CAN COMMUNICATION