MSP430 IIC通信

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#include<msp430f149.h>#define OP_READ 0xa1                    //器件地址读#define OP_WRITE 0xa0                   //器件地址写#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 |= BIT6uchar 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读取数据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);}//向指定地址写数据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);}//从指定地址读数据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;}
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