main.c

本代码是AVR单片机的完整IIC通信程序

#include <iom16v.h>
#include <macros.h>
#include "muti_mcu_function.h"
// Sample TWI transmission commands
#define TWI_CMD_MASTER_WRITE 0x10
#define TWI_CMD_MASTER_READ  0x20

// Sample TWI transmission states, used in the main application.
#define SEND_DATA             0x01
#define REQUEST_DATA          0x02
#define READ_DATA_FROM_BUFFER 0x03
#define REQUEST_DATA_two      0x04
#define TRUE 1
#define FALSE 0

#define Uchar unsigned char
struct data                     //位定义 
{ 
    unsigned bit0:1; 
    unsigned bit1:1; 
    unsigned bit2:1; 
    unsigned bit3:1; 
    unsigned bit4:1; 
    unsigned bit5:1; 
    unsigned bit6:1; 
    unsigned bit7:1; 
}bit_flag; 
#define send_busy_flag bit_flag.bit0
#define GPS_validframe_flag bit_flag.bit1
#define receive_data_flag bit_flag.bit2
#define GPS_datalen 70;

Uchar GPS_status_frame;
Uchar GPS_receive_buffer[72];
Uchar GPS_send_buffer[72];
Uchar GPS_data_conut;
Uchar GPS_data_start;
Uchar GPS_data_end;

Uchar *com_send_ptr;
Uchar com_datasen_len;

void GPS_data_send();
void delay_1ms(void)                 //8ms延时函数
  {
   unsigned int i;
   for (i=0;i<1140;i++);
  }
  
void delay_nms(unsigned int n)       //N*8 ms延时函数
  {
   unsigned int i=0;
   for (i=0;i<n;i++)
   delay_1ms();
  }
  
 unsigned char TWI_Act_On_Failure_In_Last_Transmission ( unsigned char TWIerrorMsg,unsigned status )
{
                    // A failure has occurred, use TWIerrorMsg to determine the nature of the failure
                    // and take appropriate actions.
                    // Se header file for a list of possible failures messages.
                    
                    // Here is a simple sample, where if received a NACK on the slave address,
                    // then a retransmission will be initiated.
 if(status == TWI_master_MCU)
 {
  if ( (TWIerrorMsg == TWI_MTX_ADR_NACK) | (TWIerrorMsg == TWI_MRX_ADR_NACK) )
    TWI_Start_Transceiver(status);
 }
 if(status == TWI_slave_MCU)
 {
  //PORTB = TWIerrorMsg;
  TWI_Start_Transceiver(status);
 }
    
  return TWIerrorMsg; 
}

void uart0_init(void)
{
UCSRA=0x00;
//UCSRB=(1<<RXCIE)|(1<<TXCIE)|(1<<RXEN)|(1<<TXEN);
UCSRB=0xd8;
UBRRH=0x00;
UBRRL=0x33;
//UCSRC| = BIT(URSEL);
UCSRC=BIT(URSEL)|0x06;
}
void port_init(void)
{
 DDRA  = 0xFF; // Set to ouput
 PORTA = 0x00;
 DDRB  = 0xFF; // Set to ouput
 PORTB = 0x00; // Startup pattern
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD = 0x80;
}
void system_init()
{
GPS_data_conut=1;
GPS_status_frame=0x00;
GPS_validframe_flag=FALSE;
receive_data_flag=FALSE;
}
#pragma interrupt_handler uart0_rx_isr:12
#pragma interrupt_handler uart0_tx_isr:14
void uart0_rx_isr(void)
{
 	UCSRA|=(1<<RXC);//清接收中断标志
	if(GPS_validframe_flag)
		{return;}
	if(GPS_status_frame==0x00)//////////////接收数据起始字符68H
		{
		GPS_data_start=UDR;
		if(GPS_data_start!=0x24)
			{
			GPS_status_frame=0x00;
			}
		else
			{
			GPS_status_frame=0x01;
			GPS_receive_buffer[0]=GPS_data_start;
			}
		}
	else if(GPS_status_frame==0x01)//////////开始接收数据
		{
		GPS_receive_buffer[GPS_data_conut]=UDR;
		GPS_data_conut++;
		if(GPS_data_conut==GPS_datalen+1)
			{
			GPS_status_frame=0x02;
			}
		}
	else if(GPS_status_frame==0x02)
		{
		GPS_data_end=UDR;
		if(GPS_data_end!=0x0a)
			{
			GPS_validframe_flag=FALSE;
			}
		else
			{
			GPS_receive_buffer[71]=GPS_data_end;
			GPS_validframe_flag=TRUE;
			}
		GPS_status_frame=0x00;
		receive_data_flag=TRUE;
		}
}
void uart0_tx_isr(void) 
    { 
       UCSRA|=(1<<TXC);//清发送中断标志 
       if(com_datasen_len>0)/////////////数据缓冲区数据没有发送完毕
		{
		UDR=*com_send_ptr;
		com_send_ptr++;
		com_datasen_len--;
		}
	else
		{
		send_busy_flag=FALSE;
		}
   }
void main( void )
{
  CLI();
  unsigned char messageBuf[4],TWI_slaveAddress,TWI_targetSlaveAddress,TWI_targetSlaveAddress_two;
  unsigned	char temp_data[250],pressedButton,key=0,button_check=0;
  int i;
  for(i=0;i<250;i++)
  temp_data[i]=i;
  TWI_statusReg.lastTransOK=1;
  /*DDRB  = 0xFF; // Set to ouput
  PORTB = 0x00; // Startup pattern
  DDRA  = 0xFF; // Set to ouput
  PORTA = 0x00;
  PORTD = 0x00;
  DDRD = 0x80;*/
  port_init();
  uart0_init();
  system_init();
  SFIOR&=~BIT(2);
  OSCCAL=0xb9;
  /************************/
  //always mcu keep slave status, only master in the sending datas status
  // Own TWI slave address
  TWI_slaveAddress = 0x10;
  TWI_targetSlaveAddress = 0x30;
  TWI_targetSlaveAddress_two = 0x20;
  TWI_Slave_Initialise( (TWI_slaveAddress<<TWI_ADR_BITS) | (TRUE<<TWI_GEN_BIT) ); 
  SEI();
  TWI_Start_Transceiver(TWI_slave_MCU);
  
    while(1)
  {    
  	  // pressedButton = PIND;
    // Check if the TWI Transceiver has completed an operation.
    if(receive_data_flag)
		{
		send_com_data();
		receive_data_flag=FALSE;
		GPS_validframe_flag=FALSE;
		GPS_data_conut=1;
		}
	   pressedButton = 0x01;
	   if (pressedButton)       // Check if any button is pressed
       	  { 
	  	   	 if((pressedButton==0x01))  //master check
	   		 	 {
	   	             button_check =1 ;
	   	 			 TWI_Master_Initialise();
		 			 delay_nms(100);
         			 messageBuf[0] = (TWI_targetSlaveAddress<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT); // The first byte must always consit of General Call code or the TWI slave address.
         			 messageBuf[1] = TWI_CMD_MASTER_WRITE;             // The first byte is used for commands.
	     			 messageBuf[2] = temp_data[key];
		 			 TWI_Start_Transceiver_With_Data( messageBuf, 3 , TWI_master_MCU );
		 			 //key++;
		 			 //if(key==190)key=0; 
		   		     if ( ! TWI_Transceiver_Busy() )
   		   			 	 {
	 	 	  			  	delay_nms(2);
						 }
					 else
					 	 { 
	  		  			   	TWI_Act_On_Failure_In_Last_Transmission( TWI_Get_State_Info( ), TWI_master_MCU);
					     }
					 //added for the second mcu	 
					 /*TWI_Master_Initialise();				 
					 messageBuf[0] = (TWI_targetSlaveAddress_two<<TWI_ADR_BITS) | (FALSE<<TWI_READ_BIT); // The first byte must always consit of General Call code or the TWI slave address.
         			 messageBuf[1] = TWI_CMD_MASTER_WRITE;             // The first byte is used for commands.
	     			 messageBuf[2] = temp_data[key];
		 			 TWI_Start_Transceiver_With_Data( messageBuf, 3 , TWI_master_MCU );	
					 if ( ! TWI_Transceiver_Busy() )
   		   			 	 {
	 	 	  			  	delay_nms(2);
						 }
					 else
					 	 { 
	  		  			   	TWI_Act_On_Failure_In_Last_Transmission( TWI_Get_State_Info( ), TWI_master_MCU);
					     }	  */	 
					 key++;
		 			 if(key==190)key=0;
	              }
	       }
	   else
	       {
	       	   if(button_check == 1)
		  	   	 {
		    	  	 TWI_Slave_Initialise( (TWI_slaveAddress<<TWI_ADR_BITS) | (TRUE<<TWI_GEN_BIT) );
			         TWI_Start_Transceiver(TWI_slave_MCU);
			         button_check = 0;
		         }	 
			   if ( ! TWI_Transceiver_Busy() )                              
    	   	     {
    // Check if the last operation was successful
       		        if ( TWI_statusReg.lastTransOK )
      				    {
	    
    					 	// Check if the last operation was a reception
       		 	 		    if ( TWI_statusReg.RxDataInBuf )
        		 	   		   	 {
         			   			  	  TWI_Get_Data_From_Transceiver(messageBuf, 3, TWI_slave_MCU);         
			 		   				  if ( TWI_statusReg.genAddressCall )
          			   	  			  {  
									     delay_nms(1);  
						  			  }   
    								  // Ends up here if the last operation was a reception as Slave Address Match                  
          	   		   	   			  else
         			   	  			  {
    								     // Example of how to interpret a command and respond.
       							         // TWI_CMD_MASTER_WRITE stores the data to PORTB
             						 	 if (messageBuf[0] == TWI_CMD_MASTER_WRITE)
                			                  PORTB = messageBuf[1];                            
          					            // TWI_CMD_MASTER_READ prepares the data from PINB in the transceiver buffer for the TWI master to fetch.
             							if (messageBuf[0] == TWI_CMD_MASTER_READ)
            				   			    {
   	 						   	 			 	 key = messageBuf[1];
			  					 				 PORTA=0xff; 
			  									 messageBuf[0]= temp_data[key];                     
              					 				 TWI_Start_Transceiver_With_Data( messageBuf, 1, TWI_slave_MCU );
			           
            		   		   			    }
          				  			  }
                      			 }
    							 // Ends up here if the last operation was a transmission                  
        	   		   	     else
        			  		 	 {
								 //            __no_operation(); // Put own code here.
        	  		  			 }			
    							 // Check if the TWI Transceiver has already been started.
    							 // If not then restart it to prepare it for new receptions.             
             		if ( ! TWI_Transceiver_Busy() )
             		   {
          	  		   	    TWI_Start_Transceiver(TWI_slave_MCU);
       		 		   }      
      	  		}
    // Ends up here if the last operation completed unsuccessfully
       		   else
       		    {
           		   TWI_Act_On_Failure_In_Last_Transmission( TWI_Get_State_Info(), TWI_slave_MCU );
           		}
    	 }
  } 	   	   	  
}
}
void GPS_data_send()
{
	if(!send_busy_flag)
    		{
    		com_datasen_len=72;
		com_datasen_len--;
		com_send_ptr=GPS_receive_buffer;
		send_busy_flag=TRUE;
	 	UDR=*com_send_ptr++;
    		}
}