用AtmelStudio6.2跑mega16例程(69)MAX6955驱动LED

/*

 * GccApplication32.c

 *

 * Created: 2014-12-11 22:11:01

 *  Author: Administrator

 */ 



#define F_CPU 4000000UL

#include <avr/io.h>

#include <util/twi.h>

#include <util/delay.h>

#include <string.h>

#include <stdint.h>



#define MAX6955R 0b11000001 

#define MAX6955W 0B11000000 



#define Wait() while((TWCR & _BV(TWINT))==0)

#define START() {TWCR = _BV(TWINT) | _BV(TWSTA) | _BV(TWEN);Wait();}

#define STOP() (TWCR = _BV(TWINT)| _BV(TWSTO) | _BV(TWEN) )

#define WriteByte(x) {TWDR=(x);TWCR = _BV(TWINT)|_BV(TWEN);Wait();}

#define ACK() (TWCR |= _BV(TWEA))

#define NACK() (TWCR &= ~_BV(TWEA))        



char  SEG_LED_String[] = "01234567890";



uint8_t MAX6955_Write(uint8_t addr,uint8_t dat)

{

      START();

          if(TW_STATUS != TW_START) return 0;

          WriteByte(MAX6955W);

          if(TW_STATUS != TW_MT_SLA_ACK) return 0;

          WriteByte(addr);

          if(TW_STATUS != TW_MT_DATA_ACK) return 0;

          WriteByte(dat);

          if(TW_STATUS != TW_MT_DATA_ACK) return 0;

          STOP();

          _delay_ms(20);

          return 1;

}



void MAX6955_INIT()

{

   MAX6955_Write(0x01,0xFF);

   MAX6955_Write(0x02,0x03);

   MAX6955_Write(0x03,0x07);

   MAX6955_Write(0x04,0x01);

   

   MAX6955_Write(0x06,0x00);

   MAX6955_Write(0x0c,0x00);

   

   MAX6955_Write(0x07,0x01);

   _delay_ms(1000);

   MAX6955_Write(0x07,0x00);        

}



        

int main(void)

{

    uint8_t i,j,Len = strlen(SEG_LED_String);

        DDRD = 0xFF; PORTD = 0x00;

        MAX6955_INIT();

        while(1)

    {

        //TODO:: Please write your application code

                for(i = 0;i<Len;i+=8)

                {

                   for(j = 0; j< 8;j++)

                   MAX6955_Write(0x20 | j,(uint8_t)SEG_LED_String[i+j]);

                   for(;j<8;j++)

                   MAX6955_Write(0x20 | j,(uint8_t)(' '));

                   _delay_ms(2000);

                }

    }

}