å°±å¼ä¸ªAT24C02读åç¨åºï¼æ³¨é详ç»çè¿ä¸ªä¹åºè¯¥ç¨ä¸å°ä¸é¨çæ¶éè¯çï¼æè·¯ï¼å¼æºè¿å
¥ä¸»å¾ªç¯ä¹å读åè¯çä¸çæ°æ®ï¼è®¾ç½®ä¸ªæ å¿ä½æ²¡30ç§ååä¸æ¬¡ãæè
ä½ç§=0æ为60æ¶ååä¸æ¬¡ä¹æ¯ååç§å¸åææå¼ï¼å©ç¨åçæºæ¬èº«çå®æ¶å¨ï¼ä¾å¦æ¯ä¸ª50msä¸æä¸æ¬¡20次就æ¯ä¸ç§ï¼bit ack; //åºçæ å¿ä½sbit SDA=P2^1;
sbit SCL=P2^0;/*------------------------------------------------
å¯å¨æ»çº¿
------------------------------------------------*/
void Start_I2c()
{
SDA=1; //åéèµ·å§æ¡ä»¶çæ°æ®ä¿¡å·
_Nop();
SCL=1;
_Nop(); //èµ·å§æ¡ä»¶å»ºç«æ¶é´å¤§äº4.7us,延æ¶
_Nop();
_Nop();
_Nop();
_Nop();
SDA=0; //åéèµ·å§ä¿¡å·
_Nop(); //èµ·å§æ¡ä»¶éå®æ¶é´å¤§äº4μ
_Nop();
_Nop();
_Nop();
_Nop();
SCL=0; //é³ä½I2Cæ»çº¿ï¼åå¤åéææ¥æ¶æ°æ®
_Nop();
_Nop();
}
/*------------------------------------------------
ç»ææ»çº¿
------------------------------------------------*/
void Stop_I2c()
{
SDA=0; //åéç»ææ¡ä»¶çæ°æ®ä¿¡å·
_Nop(); //åéç»ææ¡ä»¶çæ¶éä¿¡å·
SCL=1; //ç»ææ¡ä»¶å»ºç«æ¶é´å¤§äº4μ
_Nop();
_Nop();
_Nop();
_Nop();
_Nop();
SDA=1; //åéI2Cæ»çº¿ç»æä¿¡å·
_Nop();
_Nop();
_Nop();
_Nop();
}
/*----------------------------------------------------------------
åèæ°æ®ä¼ éå½æ°
å½æ°åå: void SendByte(unsigned char c);
åè½: å°æ°æ®cåéåºå»,å¯ä»¥æ¯å°å,ä¹å¯ä»¥æ¯æ°æ®,åå®åçå¾
åºç,并对
æ¤ç¶æä½è¿è¡æä½.(ä¸åºçæéåºçé½ä½¿ack=0 å)
åéæ°æ®æ£å¸¸ï¼ack=1; ack=0表示被æ§å¨æ åºçææåã
------------------------------------------------------------------*/
void SendByte(unsigned char c)
{
unsigned char BitCnt;
for(BitCnt=0;BitCnt<8;BitCnt++) //è¦ä¼ éçæ°æ®é¿åº¦ä¸º8ä½
{
if((c<<BitCnt)&0x80)SDA=1; //å¤æåéä½
else SDA=0;
_Nop();
SCL=1; //ç½®æ¶é线为é«ï¼éç¥è¢«æ§å¨å¼å§æ¥æ¶æ°æ®ä½
_Nop();
_Nop(); //ä¿è¯æ¶éé«çµå¹³å¨æ大äº4μ
_Nop();
_Nop();
_Nop();
SCL=0;
}
_Nop();
_Nop();
SDA=1; //8ä½åéå®åéæ¾æ°æ®çº¿ï¼åå¤æ¥æ¶åºçä½
_Nop();
_Nop();
SCL=1;
_Nop();
_Nop();
_Nop();
if(SDA==1)ack=0;
else ack=1; //å¤ææ¯å¦æ¥æ¶å°åºçä¿¡å·
SCL=0;
_Nop();
_Nop();
} /*----------------------------------------------------------------
åèæ°æ®ä¼ éå½æ°
å½æ°åå: unsigned char RcvByte();
åè½: ç¨æ¥æ¥æ¶ä»å¨ä»¶ä¼ æ¥çæ°æ®,并å¤ææ»çº¿é误(ä¸ååºçä¿¡å·)ï¼
åå®å请ç¨åºçå½æ°ã
------------------------------------------------------------------*/
unsigned char RcvByte()
{
unsigned char retc;
unsigned char BitCnt;
retc=0;
SDA=1; //ç½®æ°æ®çº¿ä¸ºè¾å
¥æ¹å¼
for(BitCnt=0;BitCnt<8;BitCnt++)
{
_Nop();
SCL=0; //ç½®æ¶é线为ä½ï¼åå¤æ¥æ¶æ°æ®ä½
_Nop();
_Nop(); //æ¶éä½çµå¹³å¨æ大äº4.7us
_Nop();
_Nop();
_Nop();
SCL=1; //ç½®æ¶é线为é«ä½¿æ°æ®çº¿ä¸æ°æ®ææ
_Nop();
_Nop();
retc=retc<<1;
if(SDA==1)retc=retc+1; //读æ°æ®ä½,æ¥æ¶çæ°æ®ä½æ¾å
¥retcä¸
_Nop();
_Nop();
}
SCL=0;
_Nop();
_Nop();
return(retc);
} /*----------------------------------------------------------------
åºçåå½æ°
åå: void Ack_I2c(void);
----------------------------------------------------------------*/
void Ack_I2c(void)
{
SDA=0;
_Nop();
_Nop();
_Nop();
SCL=1;
_Nop();
_Nop(); //æ¶éä½çµå¹³å¨æ大äº4μ
_Nop();
_Nop();
_Nop();
SCL=0; //æ¸
æ¶é线ï¼é³ä½I2Cæ»çº¿ä»¥ä¾¿ç»§ç»æ¥æ¶
_Nop();
_Nop();
}/*----------------------------------------------------------------
åæåå°åå¨ä»¶åéå¤åèæ°æ®å½æ°
å½æ°åå: bit ISendStr(unsigned char sla,unsigned char suba,ucahr *s,unsigned char no);
åè½: ä»å¯å¨æ»çº¿å°åéå°åï¼åå°å,æ°æ®ï¼ç»ææ»çº¿çå
¨è¿ç¨,ä»å¨ä»¶
å°åslaï¼åå°åsubaï¼åéå
容æ¯sæåçå
容ï¼åéno个åèã
å¦æè¿å1表示æä½æåï¼å¦åæä½æ误ã
注æï¼ ä½¿ç¨åå¿
须已ç»ææ»çº¿ã
----------------------------------------------------------------*/
bit ISendStr(unsigned char sla,unsigned char suba,unsigned char *s,unsigned char no)
{
unsigned char i;
for(i=0;i<no;i++)
{
Start_I2c(); //å¯å¨æ»çº¿
SendByte(sla); //åéå¨ä»¶å°å
if(ack==0)return(0);
SendByte(suba); //åéå¨ä»¶åå°å
if(ack==0)return(0);
SendByte(*s); //åéæ°æ®
if(ack==0)return(0);
Stop_I2c(); //ç»ææ»çº¿
DelayMs(1); //å¿
须延æ¶çå¾
è¯çå
é¨èªå¨å¤çæ°æ®å®æ¯
s++;
suba++;
}
return(1);
}/*----------------------------------------------------------------
åæ åå°åå¨ä»¶è¯»åèæ°æ®å½æ°
å½æ°åå: bit IRcvByte(unsigned char sla,ucahr *c);
åè½: ä»å¯å¨æ»çº¿å°åéå°åï¼è¯»æ°æ®ï¼ç»ææ»çº¿çå
¨è¿ç¨,ä»å¨ä»¶å°
åslaï¼è¿åå¼å¨c.
å¦æè¿å1表示æä½æåï¼å¦åæä½æ误ã
注æï¼ ä½¿ç¨åå¿
须已ç»ææ»çº¿ã
----------------------------------------------------------------*/
/*bit IRcvByte(unsigned char sla,unsigned char *c)
{
Start_I2c(); //å¯å¨æ»çº¿
SendByte(sla+1); //åéå¨ä»¶å°å
if(ack==0)return(0);
*c=RcvByte(); //读åæ°æ®
NoAck_I2c(); //åééå°±çä½
Stop_I2c(); //ç»ææ»çº¿
return(1);
}*/
/*----------------------------------------------------------------
åæåå°åå¨ä»¶è¯»åå¤åèæ°æ®å½æ°
å½æ°åå: bit ISendStr(unsigned char sla,unsigned char suba,ucahr *s,unsigned char no);
åè½: ä»å¯å¨æ»çº¿å°åéå°åï¼åå°å,读æ°æ®ï¼ç»ææ»çº¿çå
¨è¿ç¨,ä»å¨ä»¶
å°åslaï¼åå°åsubaï¼è¯»åºçå
容æ¾å
¥sæåçåå¨åºï¼è¯»no个åèã
å¦æè¿å1表示æä½æåï¼å¦åæä½æ误ã
注æï¼ ä½¿ç¨åå¿
须已ç»ææ»çº¿ã
----------------------------------------------------------------*/
bit IRcvStr(unsigned char sla,unsigned char suba,unsigned char *s,unsigned char no)
{
unsigned char i; Start_I2c(); //å¯å¨æ»çº¿
SendByte(sla); //åéå¨ä»¶å°å
if(ack==0)return(0);
SendByte(suba); //åéå¨ä»¶åå°å
if(ack==0)return(0); Start_I2c();
SendByte(sla+1);
if(ack==0)return(0); for(i=0;i<no-1;i++)
{
*s=RcvByte(); //åéæ°æ®
Ack_I2c(); //åéå°±çä½
s++;
}
*s=RcvByte();
NoAck_I2c(); //åééåºä½
Stop_I2c(); //ç»ææ»çº¿
return(1);
}
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