main.c

AVR单片机实现SPI通信完整源码,可直接拿过来用了

// Compiler : IAR EWAVR
// Target : M8
// Crystal: 8Mhz
// Date   :2006-12-01

#include  <iom8.h>
#include  <inavr.h>
#include  <iomacro.h>
#include  "main.h"
#include  "spi.c"
#include  "usart.c"

//#define  _EEPUT(ADR,VAL)  (*((unsigned char _eeprom *)ADR) = VAL)   //write the eeprom
//#define  _EEGET(VAL,ADR)  (VAR = *((unsigned char _eeprom *)ADR))   //read the eeprom
void port_init(void)                      //I/0 ports initialize
{
  PORTB = 0x00;
  DDRB  = 0x00;
  PORTC = 0x00;                            //m103 output only
  DDRC  = 0x00;
  PORTD = 0x00;
  DDRD  = 0xD0;                           //PORD6,7 is out
}

void watchdog_init(void)                  //WATCHDOG initialize
{
  __watchdog_reset();                      //this prevents a timout on enabling
  WDTCR = 0x08;                            //WATCHDOG ENABLED - dont forget to issue WDRs
}
//^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
void delay(uchar time_num)                 //general delay function
{
  uchar i;
  while(time_num--)
  {
    i = 200;
    while(i--)
      ;
  }
}

void delay_adc(uchar time_num)            //delay function for adc convertion
{
    while(time_num--)
      ;
}


//******************************************************
//Encoder
//external interrupt initialize
void ext_interrupt_init()
{
  ;
}

//ADC initialize
// Conversion time: 3uS
void adc_init(void)                        //ADC initialize
{
  ADCSR = 0x00;                            //disable adc
  ADMUX = 0x20;                            //AREF reference;left adjust;select adc input 0
  ACSR  = 0x80;                            //Analog Comparator Disable
  ADCSR = 0x81;                            //ADC enable;division factor :2;ADC interrupt disable
}
//*************************************************************************
//ADC result deal with
//every time see about if the ADC convertion complete
//afer delay time over
void adc_result_deal()
{
  uchar i = 0;
  do
  {
    ADMUX &= 0xF0;
    ADMUX |= i;                             //change the ADC channel
    SET_BIT(ADCSR,6);                       //start ADC convertion
    delay_adc(50);                          //wait for ADC convertion complete
    if(ADCSR & 0x10)
    {
      ;                                     //save ADC result
    }
    SET_BIT(ADCSR,6);                       //start ADC convertion
    delay_adc(50);                          //wait for ADC convertion complete
    if(ADCSR & 0x10)
    {
      adc_result[i++] = ADCH;               //save ADC result
    }
  }while(i <= 3);
}

//*************************************************************************
void Timer0_init()                        	//timer0 initialize
{
    TCCR0 = 0x00;                         	//stop timer0
    TCNT0 = 0x9C;                         	//100 uSEC time
    TCCR0 = 0x02;                         	//clock select clkI/8/(from prescaler) start timer
}

//Timer0 interrupt server
#pragma vector = TIMER0_OVF_vect          	//Timer0 interrupt server program
__interrupt void timer0_ovf_isr(void)
{
    TCNT0 = 0x9C;                         	//reload counter value
    LED_CONTROL_FLAG = 0x01;
}

//encoder scan ,use the external interrupt pins
//

void  main()
{
  	uchar temp_data;
    __disable_interrupt();                			//disable interrupt
    dsp_boot_wait();								//wait for DSP bootloader relate port are all Hi-Z
    //while((PIND & 0x20) == 0x20);					//if pind.5 is high wait until "XF" is low
    port_init();                          			//port initialize
    //watchdog_init();                      		//watchdog initialize
    //Timer0_init();                        		//Timer0 initialize
    adc_init();                           			//ADC initialize
    MCUCR = 0x00;                         			//MCU control register
    TIMSK = 0x01;                         			//Timer0 interrupt enable
    uart0_init();
    SPI_init();
    P_uart_data = uart_ping_data;
    //eep_program_enable();							//initilize AT25128,program enable
    __enable_interrupt();                 			//interrupt enable
    //SET_BIT(PORT_SPI,SS);                 		//SS is high
    //uart_rec_data =0x00;
    status_flag.at_all = 0x00;
    status_flag.bit0 = 1;
    SPI_once_end_flag = 0x01;						//initilize the flag,for the first writing buffer
    while(1)
    {
      	__watchdog_reset();                     	//reset watchdog
      	adc_result_deal();
        //***********write the eeprom******************************
        if(adc_result[2] > 0x80)
        {
       		put_spi_char();
      		if(SPI_op_code == 0x00)												//the array first data transmit start
        	{
          		if((SPI_Rstatus_flag == 0x00) || ((SPI_status & 0x01) == 0x01)) //not read register or eep busy
            	{
              		SET_BIT(PORT_SPI,SS);          								//
                	SPI_Rstatus_flag = 0x01;									//set flag for read the status register
                	CLR_BIT(PORT_SPI,SS);										//pull down the SS
          			SPDR = RDSR;												//read the status
            	}
          		if(((SPI_status & 0x01) == 0x00) && (SPI_Rstatus_flag == 3))	//eeprom in ready state
            	{
                  	if(SPI_end_flag == 0x00)
                  	{
						SET_BIT(PORT_SPI,SS);          							//pull up SS
						if(SPI_address_count == 64)
						{
							SPI_address_count = 0x00;							//clear the data num counter
							temp_data = SPI_tx_addl;
							SPI_tx_addl += SPI_tx_counter;						//adjust the write address
							if(SPI_tx_addl < temp_data)
							{
								SPI_tx_addh += 1;
							}
							SET_BIT(SPCR,7);									//Enable SPI interrupt
						}
          				CLR_BIT(PORT_SPI,SS);									//pull down the SS
        				SPDR = WREN;                     						//set write enable latch
                  	}
                  	else														//send programming protect code
                  	{
						SET_BIT(PORT_SPI,SS);          							//pull up SS
                        CLR_BIT(PORT_SPI,SS);									//pull down the SS
                        SPDR = WREN;											//
                  	}
            	}
        	}
        }
        //**********read the eeprom for test***********************
        else
         	SPI_rx_flag = 1;
        if(SPI_rx_flag == 0x01)
        {
       		if(SPI_rx_counter == 0x00)										//the array first data transmit start
        	{
          		SET_BIT(PORT_SPI,SS);										//
          		CLR_BIT(PORT_SPI,SS);										//pull down the SS
        		SPDR = READ;                     							//set write enable latch
        	}	
            if(SPI_rx_counter == 36)
            {
              	SET_BIT(PORT_SPI,SS);										//
          		CLR_BIT(PORT_SPI,SS);										//pull down the SS
        		SPDR = RDSR;    											//read status register
            }
        }
        //**********************************************************
      	if(uart_ping_data[0] == 0x5A)
      	{
        	usart_transmit(SPI_rx_buffer);          						//transmit data
            SPI_rx_counter = 0x00;
        	uart_ping_data[0] = 0x00;               						//transmit stop
      	}
        if(SPI_end_flag == 0x01)											//
        {
          	SET_BIT(PORTD,7);
    		SET_BIT(PORTD,6);
        }
        if(adc_result[2] < 0x80)
        {
          	SET_BIT(PORTD,7);
            CLR_BIT(PORTD,6);
        }											
      	delay_adc(200);
    }
}