hard_iic.h

来自「7"车载液晶电视机 控制程序源码 WinRar3.2压缩 MCU ATMega8」· C头文件 代码 · 共 100 行

/*====================
====================*/
#define ERROR_ADD_UP 6000
unsigned char iic_start(void)
{
  unsigned int i=0;
  TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);
  while (!(TWCR & (1<<TWINT)))
  {
    i++;
	if(i==ERROR_ADD_UP)
	  return 0;
  }
  if ((TWSR & 0xF8) == 0x08 || (TWSR & 0xF8) == 0x10)
    return 1;
  return 0;
}
/////////////////////
unsigned char iic_send(unsigned char x)
{
  unsigned int i=0;
  TWDR = x;
  TWCR = (1<<TWINT) | (1<<TWEN);
  while (!(TWCR & (1<<TWINT)))
  {
    i++;
	if(i==ERROR_ADD_UP)
	  return 0;
  }
  if ((TWSR & 0xF8) == 0x18 || (TWSR & 0xF8) == 0x28 || (TWSR & 0xF8) == 0x40)
    return 1;
  return 0;
//  return TWSR & 0xf8;
}
//////////////////////////
unsigned char iic_receive(void)
{
  unsigned int i=0;
  TWCR = (1<<TWINT)|(1<<TWEN);
  while (!(TWCR & (1<<TWINT)))
  {
    i++;
	if(i==ERROR_ADD_UP)
	  return 0;
  }
  return TWDR;
}
/////////////////////
void iic_stop(void)
{
TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
}
/////////////////////
void iic_init(void)
{
TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
}

/*=========================================
************IIC写*********************
=========================================*/
unsigned char IICwrite(unsigned char drive,unsigned char tmp_address,unsigned char tmp_data)
{
  iic_init();
  if(iic_start()==0)
    return 0;
  if(iic_send(drive)==0)
    return 0;
  if(iic_send(tmp_address)==0)
    return 0;
  if(iic_send(tmp_data)==0)
    return 0;
  iic_stop();
  return 1;
}
/*=========================================
************IIC读*********************
=========================================*/
unsigned char IICread(unsigned char drive,unsigned char tmp_address)
{
  register unsigned char tmp;
  iic_stop();
  if(iic_start()==0)
    return 0;
  if(iic_send(drive)==0)
    return 0;
  if(iic_send(tmp_address)==0)
    return 0;
  if(iic_start()==0)
    return 0;
  if(iic_send(drive|0x01)==0)
    return 0;
  tmp=iic_receive();
  iic_stop();
  return tmp;
}
/*===================
END
====================*/