at24c02.h

PWM电机正反转C程序！包括电路图！很受欢迎的！

/****AT24C02 DRIVER****/
#define OP_READ  0xa1 
#define OP_WRITE 0xa0  // 器件地址以及写入操作
#define MAX_ADDR 0x05  // AT24C02最大地址为0xff

sbit SDA = P1^2;
sbit SCL = P1^1;

void start();
void stop();
unsigned char shin();
bit shout(unsigned char write_data);
unsigned char read_random(unsigned char random_addr);
void write_byte( unsigned char addr, unsigned char write_data);
void fill_byte(unsigned char fill_data);
void delayms(unsigned char ms);

void start()
// 开始位
{
 SDA = 1;
 SCL = 1;
 _nop_();
 _nop_();
 SDA = 0;
 _nop_();
 _nop_();
 _nop_();
 _nop_();
 SCL = 0;
} 

void stop()
// 停止位
{
 SDA = 0;
 _nop_();
 _nop_();
 SCL = 1;
 _nop_();
 _nop_();
 _nop_();
 _nop_();
 SDA = 1;
}

unsigned char shin()
// 从AT24Cxx移入数据到MCU
{
 unsigned char i,read_data;
 for(i = 0; i < 8; i++)
 {
  SCL = 1;
  read_data <<= 1;
  read_data |= (unsigned char)SDA;
  SCL = 0;
 }
 return(read_data);
}
bit shout(unsigned char write_data)
// 从MCU移出数据到AT24Cxx
{
 unsigned char i;
 bit ack_bit;
 for(i = 0;i<8;i++)  //循环移入8个位
 {
  SDA = (bit)(write_data & 0x80);
  _nop_();
  SCL = 1;
  _nop_();
  _nop_();
  SCL = 0;
  write_data <<= 1;
 }
 SDA = 1;   // 读取应答
 _nop_();
 _nop_();
 SCL = 1;
 _nop_();
 _nop_();
 _nop_();
 _nop_();
 ack_bit = SDA;
 SCL = 0;
 return ack_bit;   // 返回AT24Cxx应答位
}

void write_byte(unsigned char addr, unsigned char write_data)
// 在指定地址addr处写入数据write_data
{
 start();
 shout(OP_WRITE);
 shout(addr);
 shout(write_data);
 stop();
 delayms(10);  // 写入周期
}

void fill_byte(unsigned char fill_data)
// 填充数据fill_data到EEPROM内
{
 unsigned char i;
 for(i = 0; i <= MAX_ADDR; i++)
 {
  write_byte(i, fill_data);
 }

}


unsigned char read_current()
// 在当前地址读取
{
 unsigned char read_data;
 start();
 shout(OP_READ);
 read_data = shin();
 stop();
 return read_data;
}

unsigned char read_random(unsigned char random_addr)
// 在指定地址读取
{
 start();
 shout(OP_WRITE);
 shout(random_addr);
 return(read_current());
}

void delayms(unsigned char ms) 
// 延时子程序
{
 unsigned char i;
 while(ms--)
 {
  for(i = 0; i < 120; i++);
 }
}