原创 Uart转1-Wire硬件控制器程序源码例程

 2008-3-2 20:05  6524 5 6 分类: MCU/ 嵌入式

hotpower 发表于 2008-3-2 19:31 侃单片机 ←返回版面

楼主： Uart转1-Wire硬件控制器程序源码例程

//UART->DS18B20
//Uart转1-Wire硬件控制器程序源码例程
//HotPower@126.com 2008.3.2 于雁塔菜地
LPC_INT8U OneWire_Start (void);
LPC_INT8U OneWire_ReadWriteByte (LPC_INT8U data);
LPC_INT8U OneWire_ReadId (LPC_INT8U *pData);

LPC_INT8U OneWire_Start (void)
{
LPC_INT8U ch;
  Uart1Config.BaudRate = BD9600;
  Uart1Config.WordLenth = WordLength8;
  Uart1Config.TwoStopBitsSelect = false;//stop=1
  UART_Init(UART1);
  UART_PutCharByPolling(UART1, 0xf0);
//ch=0xf0 无应答  ch=0xe0 有应答 ds18b20在线
  ch = UART_GetCharByPolling(UART1);
  Uart1Config.BaudRate = BD115200;
  Uart1Config.WordLenth = WordLength6;
  Uart1Config.TwoStopBitsSelect = false;//stop=1
  UART_Init(UART1);
  return ch;
}

LPC_INT8U OneWire_ReadId (LPC_INT8U *pData)
{
LPC_INT8U i, ch;
//ch=0xf0 无应答  ch=0xe0 有应答 ds18b20在线
  ch = OneWire_Start();//960us
  OneWire_ReadWriteByte(0x33);
  for (i = 0; i < 8; i ++)
  {
    pData = OneWire_ReadWriteByte(0xff);//读一个字节
  }
  return ch;//返回结果
}

LPC_INT8U OneWire_ReadWriteByte (LPC_INT8U data)
{
LPC_INT8U i, ch;
LPC_INT8U value = 0;
  for (i = 0; i < 8; i ++)
  {
    if (data & 1)
    {
      UART_PutCharByPolling(UART1, 0x3f);//1
    }
    else
    {
      UART_PutCharByPolling(UART1, 0x00);//0
    }
    ch = UART_GetCharByPolling(UART1);
    data >>= 1;
    value >>= 1;
    if (ch & 0x07)//收到1T+3T个'0'为0
    {
      value |= 0x80;
    }
  }
  return value;
}

void main (void)
{
char RecData, TranBuff[30];
  if(SysInit() == 0)
  {
    // Start user program
    __enable_interrupt();
    UserStart();
  }

  __disable_interrupt();
  OneWire_ReadId(TranBuff);//读18b20的器件ID=28 2D 95 1D 00 00 00 22
  while(1);
}

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