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eCAN basic setup problem

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Posted by stan2992

on Jul 11 2008 07:51 AM

Hello,

I have a MSc project in mobile robotics which involves the use of TMS320F2812 DSP and CAN. I would like to setup a test configuration. I compiled example programs from TI but unfortunately there is no signal change on the CAN TX pin. During debugging I noticed, that the program never actually leaves the InitECan function because it gets trapped in a loop waiting for the CCE bit to be set - and this does not happen. Forcing a change with Code Composer lets the program through, but there is no sign of CAN frames. I would be very happy if anyone could help.

Regards,

stan

All Replies

Posted by JayBe

on Jul 17 2008 07:16 AM

Prodigy95 points

Hi Stan,

have You connetced a transceiver to the CAN-Pins of the CPU and have You wired the CAN-Bus correctly ? Incorrect connection of thee Transceiver as well as a shortcut on the CAn-bus can cause this error.

The CPU has to sense CYNRX high prior able to set the CCE to one. For our systems we had to implement a break inside this loop, because sometimes the system does have a corrupted CAN-bus.

/* Enter setup mode */
ECanaRegs.CANMC.bit.CCR = 1 ;
CCR_timeoutCounter = 0;
while(ECanaRegs.CANES.bit.CCE != 1 ) // Wait for CCE bit to be set...
{
if (CCR_timeoutCounter++ > MAX_CCR_TIMEOUT_COUNTER)
{
    ECanaRegs.CANMC.bit.CCR = 0;
    status = CAN_ERROR;
    return status;
}
}

Regards,

JayBe

Posted by Gaston_Melo_Arg

on Jul 29 2008 21:32 PM

Genius4065 points

Sta...i'm gaston and i new in the dsp family, i have a ezdsk 28335 and my problem is i can't run a program because i don't know how to make a .cmd, i just want to do a sine wave, i know how to do the c code but de .cmd not. can you help me. Thanks. Gaston.

Posted by Mr M

on Aug 11 2008 03:30 AM

Prodigy90 points

Hello Remember to activate the CAN clock in DSP281x_SysCtrl.c. SysCtrlRegs.PCLKCR.bit.ECANENCLK=1;