LAUNCHXL-F28379D: CAN data transfer between 2 LaunchXL-F28379D boards using C2000ware example programs

Hey Thomas, 

Thanks for your query.

Thomas Cox said:

simple Tx and simple Rx example projects were not designed as a compatible pair

They were designed to be a compatible pair as found in the C2000ware package. There might be an error in your implementation.

Kindly see the personal message to get the contact details to share the zip files.

Thanks,

Sahil Deshpande.

Thomas,

    Have you looked at the debug tips in www.ti.com/lit/sprace5? 

I have looked at the tips, and believe I am in compliance with all of them. I found your document after I created my modified projects, and struggled with how to import a project based on an existing C2000ware project, had not gone back and used the process in section 4.2 because my new projects seemed to build cleanly and run. This morning I created a 2nd copy of  the simple receive project for CAN-B by following section 4.2. I just ran the project pair on my two LaunchXL-F28379D boards. The simple receive project still receives all 0x00 data bytes, not the values transmitted by the simple transmit project.

Sahil - I have sent the ZIP file containing my two modified CAN simple Tx and Rx projects, as you requested.

Since ZIP files are a problem, how about this? If you follow section 4.2 of make a project based on the generic C2000ware example can_ex5_simple_receive, name the new project to reflect CANB on LaunchXL-F28379D, and replace the generic source file with the source code below, configured per my changes listed above, and then let me know if you find any errors in my source code changes that would cause the program to fail to decode from a project based on can_ex4_simple_transmit, but modified as below to use CANB on a LaunchXL board?

//#############################################################################
//
// FILE:  CANB_ex5_simple_receive_LaunchXL.c
//
// TITLE:   CAN Simple Receive Example
//
//! \addtogroup driver_example_list
//! <h1> CAN simple example that illustrates data reception </h1>
//!
//! This example initializes CAN module B for Reception. When a frame with a
//! STD-MSGID of 0x1 is received, the data will be copied in mailbox 1.
//! If a message of any other MSGID is received, an ACK will be provided.
//! GPIO65 will be toggled in both cases. Completion of reception
//! is determined by polling. No interrupts are used.
//! Note: RxOK bit is set even when the MSGID does not match.
//!
//! \b Hardware \b Required \n
//!  - An external CAN node that transmits to CAN-B on the C2000 MCU
//!
//! \b Watch \b Variables \n
//!  - rxMsgCount - A counter for the number of messages received
//!  - rxMsgData - An array with the data that was received
//!
//
//#############################################################################
// $TI Release: F2837xD Support Library v3.12.00.00 $
// $Release Date: Fri Feb 12 19:03:23 IST 2021 $
// $Copyright:
// Copyright (C) 2013-2021 Texas Instruments Incorporated - http://www.ti.com/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//   Redistributions of source code must retain the above copyright
//   notice, this list of conditions and the following disclaimer.
//
//   Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the
//   distribution.
//
//   Neither the name of Texas Instruments Incorporated nor the names of
//   its contributors may be used to endorse or promote products derived
//   from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// $
//#############################################################################

//
// Included Files
//
#include "driverlib.h"
#include "device.h"

//
// Defines
//
#define MSG_DATA_LENGTH    0   // "Don't care" for a Receive mailbox
#define RX_MSG_OBJ_ID      1   // Use mailbox 1

//
// Globals
//
uint16_t rxMsgData[8];
uint16_t rxLastDataRcvd[8];
volatile uint32_t rxMsgCount = 0;

//
// Main
//
void main( void )
{
	//
	// Initialize device clock and peripherals
	//
	Device_init();

	//
	// Initialize GPIO
	//
	Device_initGPIO();

	//
	// Configure GPIO pins for CANTX/CANRX
	//
	GPIO_setPinConfig( DEVICE_GPIO_CFG_CANRXB );
	GPIO_setPinConfig( DEVICE_GPIO_CFG_CANTXB );

	//
	// Configure GPIO pin which is toggled upon message reception
	//
	GPIO_setPadConfig( 15U, GPIO_PIN_TYPE_STD );
	GPIO_setDirectionMode( 15U, GPIO_DIR_MODE_OUT );

	//
	//	Toggle LED1 on the demo board too.
	//
#if defined(_LAUNCHXL_F28379D)
	GPIO_setPadConfig( 31U, GPIO_PIN_TYPE_STD );
	GPIO_setDirectionMode( 31U, GPIO_DIR_MODE_OUT );
#else
	GPIO_setPadConfig( 65U, GPIO_PIN_TYPE_STD );
	GPIO_setDirectionMode( 65U, GPIO_DIR_MODE_OUT );
#endif

	//
	// Initialize the CAN controller
	//
	CAN_initModule( CANB_BASE );

	//
	// Set up the CAN bus bit rate to 500kHz for each module
	// Refer to the Driver Library User Guide for information on how to set
	// tighter timing control. Additionally, consult the device data sheet
	// for more information about the CAN module clocking.
	//
	CAN_setBitRate( CANB_BASE, DEVICE_SYSCLK_FREQ, 500000, 16 );

	//
	// Initialize the receive message object used for receiving CAN messages.
	// Message Object Parameters:
	//      CAN Module: B
	//      Message Object ID Number: 1
	//      Message Identifier: 0x1
	//      Message Frame: Standard
	//      Message Type: Receive
	//      Message ID Mask: 0x0
	//      Message Object Flags: None
	//      Message Data Length: "Don't care" for a Receive mailbox
	//
	CAN_setupMessageObject( CANB_BASE, RX_MSG_OBJ_ID, 0x1,
							CAN_MSG_FRAME_STD, CAN_MSG_OBJ_TYPE_RX, 0,
							CAN_MSG_OBJ_NO_FLAGS, MSG_DATA_LENGTH );

	//
	// Start CAN module A operations
	//
	CAN_startModule( CANB_BASE );

	//
	// Start reception - Just wait for data from another node
	//
	while( 1 )
	{
		//
		// Poll RxOk bit in CAN_ES register to check completion of Reception
		//
		if((( HWREGH( CANB_BASE + CAN_O_ES) & CAN_ES_RXOK )) == CAN_ES_RXOK )
		{
			//
			// Get the received message
			//
			int i = 0;
			CAN_readMessage( CANB_BASE, RX_MSG_OBJ_ID, rxMsgData );
			GPIO_togglePin( 15U );
			GPIO_togglePin( 31U );
			rxMsgCount++;
			for( i = 0; i < 8; i++) {
				rxLastDataRcvd[i] = rxMsgData[i];
			}
		}
	}
}

//
// End of File
//

I had trouble entering the source code for the Tx program adapted for LaunchXL-F28379D and CANB. Let me try it again.

//#############################################################################
//
// FILE:   canB_ex4_simple_transmit_LaunchXL.c
//
// TITLE:   CAN simple External Transmit Example for the LaunchXL-F28379D demo board.
//
//! \addtogroup driver_example_list
//! <h1> CAN-B External Transmit </h1>
//!
//! This example initializes CAN module B for external communication.
//! CAN-B module is setup to transmit data for "n" number of times,
//! where "n" is the value of TXCOUNT. Another CAN node configured for the
//! same bit-rate is needed to provide the ACK. No interrupts are used.
//!
//! \b Hardware \b Required \n
//!  - A C2000 board with CAN transceiver and another CAN node configured
//!    for the same bit-rate to provide the ACK.
//!
//! \b Watch \b Variables \n
//!  - TXCOUNT - Adjust to set the number of messages to be transmitted
//!  - txMsgCount - A counter for the number of messages sent
//!  - txMsgData - An array with the data being sent
//!
//
//#############################################################################
// $TI Release: F2837xD Support Library v3.12.00.00 $
// $Release Date: Fri Feb 12 19:03:23 IST 2021 $
// $Copyright:
// Copyright (C) 2013-2021 Texas Instruments Incorporated - http://www.ti.com/
//
// Redistribution and use in source and binary forms, with or without 
// modification, are permitted provided that the following conditions 
// are met:
// 
//   Redistributions of source code must retain the above copyright 
//   notice, this list of conditions and the following disclaimer.
// 
//   Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the 
//   documentation and/or other materials provided with the   
//   distribution.
// 
//   Neither the name of Texas Instruments Incorporated nor the names of
//   its contributors may be used to endorse or promote products derived
//   from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// $
//#############################################################################

//
// Included Files
//
#include "driverlib.h"
#include "device.h"

//
// Defines
//
#define TXCOUNT  		1000
#define MSG_DATA_LENGTH    8
#define TX_MSG_OBJ_ID      1

//
// Globals
//
volatile unsigned long i;
volatile uint32_t txMsgCount = 0;
uint16_t txMsgData[8];

//
// Main
//
void main( void )
{
	//
	// Initialize device clock and peripherals
	//
	Device_init();

	//
	// Initialize GPIO and configure GPIO pins for CANTX/CANRX
	// on module B
	//
	Device_initGPIO();
	GPIO_setPinConfig( DEVICE_GPIO_CFG_CANRXB );
	GPIO_setPinConfig( DEVICE_GPIO_CFG_CANTXB );

	// Configure GPIO pins which are toggled upon message reception.
	//	Monitor GPIO15 with an oscilloscope.
	//
	GPIO_setPadConfig( 15U, GPIO_PIN_TYPE_STD );
	GPIO_setDirectionMode( 15U, GPIO_DIR_MODE_OUT );

	//
	//	Toggle the LED too
	//
#if defined(_LAUNCHXL_F28379D)
	GPIO_setPadConfig( 31U, GPIO_PIN_TYPE_STD );
	GPIO_setDirectionMode( 31U, GPIO_DIR_MODE_OUT );
#else
	GPIO_setPadConfig( 65U, GPIO_PIN_TYPE_STD );
	GPIO_setDirectionMode( 65U, GPIO_DIR_MODE_OUT );
#endif

	//
	// Initialize the CAN controllers
	//
	CAN_initModule( CANB_BASE );

	//
	// Set up the CAN bus bit rate to 500kHz for each module
	// Refer to the Driver Library User Guide for information on how to set
	// tighter timing control. Additionally, consult the device data sheet
	// for more information about the CAN module clocking.
	//
	CAN_setBitRate( CANB_BASE, DEVICE_SYSCLK_FREQ, 500000, 16 );

	//
	// Initialize the transmit message object used for sending CAN messages.
	// Message Object Parameters:
	//      CAN Module: B
	//      Message Object ID Number: 1
	//      Message Identifier: 0x95555555
	//      Message Frame: Extended
	//      Message Type: Transmit
	//      Message ID Mask: 0x0
	//      Message Object Flags: None
	//      Message Data Length: 4 Bytes
	//
	CAN_setupMessageObject( CANB_BASE, TX_MSG_OBJ_ID, 0x95555555,
	                        CAN_MSG_FRAME_EXT, CAN_MSG_OBJ_TYPE_TX, 0,
	                        CAN_MSG_OBJ_NO_FLAGS, MSG_DATA_LENGTH );

	//
	// Initialize the transmit message object data buffer to be sent
	//
	txMsgData[0] = 0x01;
	txMsgData[1] = 0x23;
	txMsgData[2] = 0x45;
	txMsgData[3] = 0x67;
	txMsgData[4] = 0x89;
	txMsgData[5] = 0xAB;
	txMsgData[6] = 0xCD;
	txMsgData[7] = 0xEF;

	//
	// Start CAN module B operations
	//
	CAN_startModule( CANB_BASE );

	//
	// Transmit messages from CAN-B
	//
//	while( 1 )
	//
	// Comment for infinite transmissions
	//
	for( i = 0; i < TXCOUNT; i++ )
	//
	{
		CAN_sendMessage( CANB_BASE, TX_MSG_OBJ_ID, MSG_DATA_LENGTH, txMsgData );

		//
		// Poll TxOk bit in CAN_ES register to check completion of transmission
		//
		while( (( HWREGH( CANB_BASE + CAN_O_ES) & CAN_ES_TXOK)) != CAN_ES_TXOK )
		{
		}
		//	Visibly signal end of transmission.
		GPIO_togglePin( 15U );
		GPIO_togglePin( 31U );
		DEVICE_DELAY_US( 10000 );
	}
	//
	// Stop application
	//
	asm("   ESTOP0");
}

//
// End of File
//

Is anyone still participating this thread? I have heard from neither Salil or Hareesh since their initial replies, more than 2 days ago.

If anyone is investigating the apparent problem I have encountered when applying C2000ware drivers and example programs to CANB on a LaunchXL-F28379D board, can they post some sort of notification of status and any progress made?

Thanks.

Thomas,

    Sahil is unwell. I will take a look at this today, else first thing tomorrow. 

Sorry to hear that Sahil is ailing. Thank you for pursuing this issue. I look forward to hearing your findings.

Thomas,

                I will take a look at your source code. In the interim, please answer these questions: 

Do you have a CAN bus analyzer that logs the frames transmitted on the bus? 

Can you provide a scope capture of the CANTX and CANRX pins of the transmitting node? Ideally, I'd like to see an image similar to Figure 2-6. Waveform at the CANRXA Pin in www.ti.com/lit/sprace5. Specifically, I want to know whether your receiving node is able to ACK the received frame. If the ACK is correctly seen, it tells me that there are no H/W issues and we can shift our focus to correct configuration of the receive message object. 

I find the line " The simple receive project still receives all 0x00 data bytes, not the values transmitted by the simple transmit project" intriguing. Are you saying the frame itself is received, but the data bytes are not received? If so, I'd like to know how you determined that.

Thomas,

    You are using 0x95555555 as the ARBID for the Transmit object, but 0x1 for the Receive object. That will not work. Change that to 0x95555555 and it should receive correctly. Below are the changes:

CAN_setupMessageObject( CANB_BASE, RX_MSG_OBJ_ID, 0x95555555,
CAN_MSG_FRAME_EXT, CAN_MSG_OBJ_TYPE_RX, 0,
CAN_MSG_OBJ_NO_FLAGS, MSG_DATA_LENGTH );

In answer to your questions, not in the order asked:

2)   The hardware for CANB on LaunchXL-F28379D has CANH and CANL pins, not CANTX and CANRX. The latter are fed through an onboard transducer, and there is no easy way to access those signals

1)   My client is planning to build a cable that adds a DB9 T-tap between CANH and CANL, which we can then attach to a Peak CAN adapter to listen and log data sent between the two LaunchXL boards. I have not had the opportunity to get that data yet. When we do, it will help determine whether the problem is on the Tx or Rx side.

3)   Yes, apparently frames are received, since number received equals number sent. We monitor that by adding to the Expressions tab of CCS debugger the variable i in the Tx loop of the Tx program, and variable rxMsgCount in the Rx program. Packet contents can be monitored when programs are paused by adding to Expressions variable rxMsgData or rxLastDataRcvd in the Rx program and the variable txMsgData on the Tx program.

I made the change to the ARBID parameter as you suggested. Behavior of the system has not changed. All data bytes in the Rx program are decoded as 0x00.