main.c

MICROCHIP J1939实例代码

/*
Example 4

This example shows the same concept as Example 2, except that broadcast 
messages are used rather than messages sent to a specific address.

Both Node 0 and Node 1 should be programmed with the same code, except
that OTHER_NODE should be defined as the other node抯 J1939 Address.

Application Maestro should be run with the following options changed 
from their default values (in addition to NAME, Address, and bit rate 
values): 

None
*/

#include <p18cxxx.h>
#include "j1939.h"

J1939_MESSAGE Msg;

// Define some arbitrary values.  They must agree with the other node's
// values.

#define OTHER_NODE		129
#define TURN_ON_LED		4	
#define TURN_OFF_LED		5	

void InterruptHandlerLow (void);

//--------------------------------------------------------------------
// Low priority interrupt vector

#pragma code InterruptVectorLow = 0x0018
void InterruptVectorLow( void )
{
  _asm
    goto InterruptHandlerLow 
  _endasm
}

//--------------------------------------------------------------------
// Low priority interrupt routine

#pragma code
#pragma interruptlow InterruptHandlerLow

void InterruptHandlerLow( void )
{
	if (PIR3 != 0x00)
		J1939_ISR();
}

//--------------------------------------------------------------------

void main( void )
{
	unsigned char	LastSwitch = 1;
	unsigned char	CurrentSwitch;

	TRISBbits.TRISB4 = 1;			// Switch pin
	TRISD = 0;							// LED pins
	LATD = 0;							// Turn off LED

	J1939_Initialization( TRUE );
   INTCONbits.PEIE = 1;		// Enable peripheral interrupts
   INTCONbits.GIE = 1;		// Enable global interrupts

	// Wait for address contention to time out
	while (J1939_Flags.WaitingForAddressClaimContention)
		J1939_Poll(5);

	// Now we know our address should be good, so start checking for
	// messages and switches.

	while (1)
	{
		CurrentSwitch = PORTBbits.RB4;
		if (LastSwitch != CurrentSwitch)
		{
			Msg.DataPage				= 0;
			Msg.Priority				= J1939_CONTROL_PRIORITY;
			Msg.DestinationAddress	= OTHER_NODE;
			Msg.PDUFormat 				= 254;
			Msg.DataLength				= 0;
			if (CurrentSwitch == 0)
				Msg.GroupExtension= TURN_ON_LED;
			else
				Msg.GroupExtension= TURN_OFF_LED;
			while (J1939_EnqueueMessage( &Msg ) != RC_SUCCESS);
			LastSwitch = CurrentSwitch;
		}

		while (RXQueueCount > 0)
		{
			J1939_DequeueMessage( &Msg );
			if (Msg.GroupExtension == TURN_ON_LED)
				LATDbits.LATD0 = 1;
			else if (Msg.GroupExtension == TURN_OFF_LED)
				LATDbits.LATD0 = 0;
		}
	}
}