|
|
程序出自 手把手教你學(xué)51單片機(jī)
#include <reg52.h>
sbit DS1302_CE = P1^7;
sbit DS1302_CK = P3^5;
sbit DS1302_IO = P3^4;
bit flag200ms = 0; //200ms定時(shí)標(biāo)志
unsigned char T0RH = 0; //T0重載值的高字節(jié)
unsigned char T0RL = 0; //T0重載值的低字節(jié)
void ConfigTimer0(unsigned int ms);
void InitDS1302();
unsigned char DS1302SingleRead(unsigned char reg);
extern void InitLcd1602();
extern void LcdShowStr(unsigned char x, unsigned char y, unsigned char *str);
void main()
{
unsigned char i;
unsigned char psec=0xAA; //秒備份，初值A(chǔ)A確保首次讀取時(shí)間后會(huì)刷新顯示
unsigned char time[8]; //當(dāng)前時(shí)間數(shù)組
unsigned char str[12]; //字符串轉(zhuǎn)換緩沖區(qū)
EA = 1; //開總中斷
ConfigTimer0(1); //T0定時(shí)1ms
InitDS1302(); //初始化實(shí)時(shí)時(shí)鐘
InitLcd1602(); //初始化液晶
while (1)
{
if (flag200ms) //每200ms讀取依次時(shí)間
{
flag200ms = 0;
for (i=0; i<7; i++) //讀取DS1302當(dāng)前時(shí)間
{
time[ i] = DS1302SingleRead(i);
}
if (psec != time[0]) //檢測(cè)到時(shí)間有變化時(shí)刷新顯示
{
str[0] = '2'; //添加年份的高2位：20
str[1] = '0';
str[2] = (time[6] >> 4) + '0'; //“年”高位數(shù)字轉(zhuǎn)換為ASCII碼
str[3] = (time[6]&0x0F) + '0'; //“年”低位數(shù)字轉(zhuǎn)換為ASCII碼
str[4] = '-'; //添加日期分隔符
str[5] = (time[4] >> 4) + '0'; //“月”
str[6] = (time[4]&0x0F) + '0';
str[7] = '-';
str[8] = (time[3] >> 4) + '0'; //“日”
str[9] = (time[3]&0x0F) + '0';
str[10] = '\0';
LcdShowStr(0, 0, str); //顯示到液晶的第一行
str[0] = (time[5]&0x0F) + '0'; //“星期”
str[1] = '\0';
LcdShowStr(11, 0, "week");
LcdShowStr(15, 0, str); //顯示到液晶的第一行
str[0] = (time[2] >> 4) + '0'; //“時(shí)”
str[1] = (time[2]&0x0F) + '0';
str[2] = ':'; //添加時(shí)間分隔符
str[3] = (time[1] >> 4) + '0'; //“分”
str[4] = (time[1]&0x0F) + '0';
str[5] = ':';
str[6] = (time[0] >> 4) + '0'; //“秒”
str[7] = (time[0]&0x0F) + '0';
str[8] = '\0';
LcdShowStr(4, 1, str); //顯示到液晶的第二行
psec = time[0]; //用當(dāng)前值更新上次秒數(shù)
}
}
}
}
/* 發(fā)送一個(gè)字節(jié)到DS1302通信總線上 */
void DS1302ByteWrite(unsigned char dat)
{
unsigned char mask;
for (mask=0x01; mask!=0; mask<<=1) //低位在前，逐位移出
{
if ((mask&dat) != 0) //首先輸出該位數(shù)據(jù)
DS1302_IO = 1;
else
DS1302_IO = 0;
//為什么這里是下降沿
DS1302_CK = 1; //然后拉高時(shí)鐘
DS1302_CK = 0; //再拉低時(shí)鐘，完成一個(gè)位的操作
}
DS1302_IO = 1; //最后確保釋放IO引腳
}
/* 由DS1302通信總線上讀取一個(gè)字節(jié) */
unsigned char DS1302ByteRead()
{
unsigned char mask;
unsigned char dat = 0;
for (mask=0x01; mask!=0; mask<<=1) //低位在前，逐位讀取
{
if (DS1302_IO != 0) //首先讀取此時(shí)的IO引腳，并設(shè)置dat中的對(duì)應(yīng)位
{
dat |= mask;
}
DS1302_CK = 1; //然后拉高時(shí)鐘
DS1302_CK = 0; //再拉低時(shí)鐘，完成一個(gè)位的操作
}
return dat; //最后返回讀到的字節(jié)數(shù)據(jù)
}
/* 用單次寫操作向某一寄存器寫入一個(gè)字節(jié)，reg-寄存器地址，dat-待寫入字節(jié) */
void DS1302SingleWrite(unsigned char reg, unsigned char dat)
{
DS1302_CE = 1; //使能片選信號(hào)
DS1302ByteWrite((reg<<1)|0x80); //發(fā)送寫寄存器指令
DS1302ByteWrite(dat); //寫入字節(jié)數(shù)據(jù)
DS1302_CE = 0; //除能片選信號(hào)
}
/* 用單次讀操作從某一寄存器讀取一個(gè)字節(jié)，reg-寄存器地址，返回值-讀到的字節(jié) */
unsigned char DS1302SingleRead(unsigned char reg)
{
unsigned char dat;
DS1302_CE = 1; //使能片選信號(hào)
DS1302ByteWrite((reg<<1)|0x81); //發(fā)送讀寄存器指令
dat = DS1302ByteRead(); //讀取字節(jié)數(shù)據(jù)
DS1302_CE = 0; //除能片選信號(hào)
return dat;
}
/* DS1302初始化，如發(fā)生掉電則重新設(shè)置初始時(shí)間 */
void InitDS1302()
{
unsigned char i;
unsigned char code InitTime[] = { //2013年10月8日 星期二 12:30:00
0x00,0x30,0x12, 0x08, 0x10, 0x02, 0x13
};
DS1302_CE = 0; //初始化DS1302通信引腳
DS1302_CK = 0;
i = DS1302SingleRead(0); //讀取秒寄存器
if ((i & 0x80) != 0) //由秒寄存器最高位CH的值判斷DS1302是否已停止
{
DS1302SingleWrite(7, 0x00); //撤銷寫保護(hù)以允許寫入數(shù)據(jù)
for (i=0; i<7; i++) //設(shè)置DS1302為默認(rèn)的初始時(shí)間
{
DS1302SingleWrite(i, InitTime[ i]);
}
}
}
/* 配置并啟動(dòng)T0，ms-T0定時(shí)時(shí)間 */
void ConfigTimer0(unsigned int ms)
{
unsigned long tmp; //臨時(shí)變量
tmp = 11059200 / 12; //定時(shí)器計(jì)數(shù)頻率
tmp = (tmp * ms) / 1000; //計(jì)算所需的計(jì)數(shù)值
tmp = 65536 - tmp; //計(jì)算定時(shí)器重載值
tmp = tmp + 12; //補(bǔ)償中斷響應(yīng)延時(shí)造成的誤差
T0RH = (unsigned char)(tmp>>8); //定時(shí)器重載值拆分為高低字節(jié)
T0RL = (unsigned char)tmp;
TMOD &= 0xF0; //清零T0的控制位
TMOD |= 0x01; //配置T0為模式1
TH0 = T0RH; //加載T0重載值
TL0 = T0RL;
ET0 = 1; //使能T0中斷
TR0 = 1; //啟動(dòng)T0
}
/* T0中斷服務(wù)函數(shù)，執(zhí)行200ms定時(shí) */
void InterruptTimer0() interrupt 1
{
static unsigned char tmr200ms = 0;
TH0 = T0RH; //重新加載重載值
TL0 = T0RL;
tmr200ms++;
if (tmr200ms >= 200) //定時(shí)200ms
{
tmr200ms = 0;
flag200ms = 1;
}
} |
|
