MSP430 IIC通信

#include<msp430f149.h>

#define OP_READ 0xa1                    //器件位址讀
#define OP_WRITE 0xa0                   //器件位址寫
#define uchar unsigned char
#define uint unsigned int 
#define SDA_OUT P1DIR |= BIT3
#define SDA_IN P1DIR &= ~BIT3
#define SCL_OUT P1DIR |= BIT2
#define SCL_IN P1DIR &= ~BIT2

#define SDA_H P1OUT |= BIT3
#define SDA_L P1OUT &= ~BIT3
#define SCL_H P1OUT |= BIT2
#define SCL_L P1OUT &= ~BIT2

#define wei_h P5OUT |= BIT5
#define wei_l P5OUT &= BIT5
#define duan_l P6OUT &= ~BIT6
#define duan_h P6OUT |= BIT6

uchar table[16] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

uchar miao;
uchar write;
int num;
void delayus(uint z)
{
  uint i,j;
  for(i = 0;i<20;i++)
    for(j=0;j<z;j++)
    {;;};
}

void start()
{
  SDA_OUT;
  SCL_OUT;
  SDA_H;
  SCL_H;
  delayus(1);
  SDA_L;
  delayus(2);
  SCL_L;
}

void stop()
{
  SDA_OUT;
  SCL_OUT;
  SDA_L;

  delayus(2);
  SCL_H;
  delayus(2);
  SDA_H;
}

void Ack24()
{
  SDA_OUT;
  SCL_OUT;
  SDA_H;
  SCL_H;

  delayus(2);
  SDA_IN;
  while(P1IN & BIT3)
      SCL_L;
  delayus(2);
}
//mcu讀取資料
uchar read_byte()
{
  uchar i,read_data;
  SDA_OUT;
  SCL_OUT;
  for(i = 0;i<8;i++)
  {
    SDA_H;
    delayus(1);
    SCL_H;
    SDA_IN;
    read_data <<= 1;
    if(P1IN & BIT3)
      read_data |= 0x01;
      SDA_OUT;
      SCL_L;   
  }
  return(read_data);
}

void write_byte(uint dat)
{
  uchar i;
  SDA_OUT;
  SCL_OUT;
  for(i = 0;i<8;i++)
  {
    if(dat&0x80)
      SDA_H;
    else
      SDA_L; 
    delayus(2);
    SCL_H;
    delayus(2);
    SCL_L;
    delayus(2);
    dat <<= 1;
  }
  SCL_L;
  delayus(2);
  SDA_H;
  delayus(2);
}

//向指定位址寫資料
void write_dat(uchar addr,uchar write_data)
{
  SDA_OUT;
  SCL_OUT;
  SDA_H;
  SCL_H;
  start();
  write_byte(OP_WRITE);
  Ack24();
  write_byte(addr);
  Ack24();
  write_byte(write_data);
  Ack24();
  stop();
  delayus(1000);
}
//從指定位址讀資料
uchar read_random(uint random_addr)
{
  uchar i;
  SDA_OUT;
  SCL_OUT;
  SDA_H;
  SCL_H;
  start();
  write_byte(OP_WRITE);
  Ack24();
  write_byte(random_addr);
  Ack24();
  start();
  write_byte(OP_READ);
  Ack24();
  i = read_byte();
  stop();
  return i;
}

void display(uchar dat)
{
  P4OUT = table[dat];
  duan_h;
  duan_l;
  P4OUT = ~(1 << num);
  wei_h;
  wei_l;
}

void Clock(void)
{
  miao++;
  if(miao==10)
    miao=0;
}

void main( void )
{
  P1DIR = 0XFF,P1OUT = 0XFF;
  P2DIR = 0XFF,P2OUT = 0XFF;
  P3DIR = 0XFF,P3OUT = 0XFF;
  P4DIR = 0XFF,P4OUT = 0XFF;
  P5DIR = 0XFF,P5OUT = 0XFF;
  P6DIR = 0XFF,P6OUT = 0XFF;
  
  SDA_OUT;
  SCL_OUT;
  SDA_H;
  SCL_L;
  
  // Stop watchdog timer to prevent time out reset
  WDTCTL = WDTPW + WDTHOLD;
  CCR0 = 32768 -1;
  TACTL = TASSEL_1 + MC_1;
  CCTL0 |= CCIE;
  _EINT();

  miao = read_random(3);
  if(miao>9) miao=0;
  
  while(1)
  {
    display(miao);
    if(write==1)
    {
      write = 0;
      write_dat(3,miao);
    }
    LPM3;
  }
}

#pragma vector = TIMERA0_VECTOR
__interrupt void TimerA_ISR(void)
{
  Clock();
  write = 1;
  LPM3_EXIT;
}