#include <msp430x14x.h> #define OP_READ 0xa1 // 器件地址以及读取操作 #define OP_WRI 0xa0 // 器件地址以及写入操作 #define uchar unsigned char #define uint unsigned int #define SDA_OUT P1D|=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 //7位段码：0--f uchar table[16] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07, 0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71}; //记录显示位数的全局变量 uchar miao; uchar write; //8M晶振时大约20us延时程序 void delayus(uint z) { uint i,j; for(i = 0;i<20;i++) for(j=0;j<z;j++) {;;}; } // 开始位 void start() { SDA_OUT; SCL_OUT; SDA_H; SCL_H; delayus(1); //20 SDA_L; delayus(2);//40 SCL_L; } // 停止位 void stop() { SDA_OUT; SCL_OUT; SDA_L; delayus(2);//20 SCL_H; delayus(2); SDA_H; } // 从AT24Cxx移入数据到 uchar shin() { 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); } // 从MCU移出数据到AT24Cxx uchar shout(uint write_data) { uchar i; uchar ack_bit; SDA_OUT; SCL_OUT; for(i = 0; i < 8; i++) // 循环移入8个位 { if(write_data&0x80) SDA_H; else SDA_L; delayus(2);//2 SCL_H; delayus(2);//2 SCL_L; delayus(2);//2 write_data <<= 1; } SDA_H; // 读取应答 delayus(2); SCL_H; //注意拉高 delayus(2); SDA_IN; if(P1IN&BIT3) ack_bit=1; else ack_bit=0; SCL_L; return ack_bit; // 返回AT24Cxx应答位 } // 在指定地址addr处写入数据write_data void write_byte(uchar addr, uchar write_data) { SDA_OUT; SCL_OUT; SDA_H; SCL_H; start(); shout(OP_WRITE); shout(addr); shout(write_data); stop(); delayus(1000);// 写入周期 } // 在当前地址读取 uint read_current() { uint read_data; start(); shout(OP_READ); read_data = shin(); stop(); return read_data; } // 在指定地址读取 uchar read_random(uint random_addr) { SDA_IN; SCL_OUT; SDA_H; SCL_H; start(); shout(OP_WRITE); shout(random_addr); return(read_current()); }
void display(uchar dat) { P4OUT = table[dat];//输出段选信号 duan_h; duan_l; P4OUT = 0x00; //设置P4，P5的输出初值 wei_h; wei_l; }
void Clock(void) { miao++; if(miao==10) miao=0; }
int main( void ) { /*下面六行程序关闭所有的IO口*/ 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_H; WDTCTL = WDTPW + WDTHOLD; CCR0 = 32768 - 1;//设置定时器A的中断时间为1S TACTL = TASSEL_1 + MC_1; //计数时钟ACLK, 增计数模式 CCTL0 |= C; //使能CCR0比较中断 _EI();//打开全局中断 miao=read_random(3) ;//从地址2中读出以前保存的数据 if(miao>9) miao=0; //防止首次读出错误数据 while(1) { display(miao); if(write==1) { write=0; write_byte(3,miao); } LPM3;//进入LPM3低功耗模式 } }
/******************************************* 函数名称：TimerA_ISR 功 能：定时器A的中断服务函数 ********************************************/ #pragma vector=MERA0_ __interrupt void TimerA_ISR(void) { Clock(); write=1; LPM3_EXIT; }
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