#include "global.h"

/**
 * 读MAX6675原始16位数据
 * 
 * @author yyq (2024/9/11/周三)
 * 
 * @param port    spi设备号 0、1、2
 * 
 * @return value  原始16位数据
 */
static unsigned short max6675_ReadReg(int port)
{
    unsigned short value;
    if(port < HW_SPI_DEVICE_NUMBER)
    {
        hw_spi_device_take(port);
        hw_spi_readwrite(port, 0, (unsigned char*)&value, 2);
        hw_spi_device_release(port);
        return value;
    }
    return 0xffff;
}

/**
 * 读MAX6675温度值
 * 
 * @author yyq (2024/9/11/周三)
 * 
 * @param port    spi设备号 0、1、2
 * @param value    读到的温度值
 * 
 * @return int  数据有效性：1有效 0无效
 */
int max6675_ReadTemp(int port,float* value)
{
  unsigned short temp;
  int data_valid;
  temp = max6675_ReadReg(port);
  temp <<= 1;
  if(temp&0x08)
  {
      data_valid=0;
  }
  else    
  {
      temp >>= 4;
      *value = (temp & 0x0fff)*0.25;
      data_valid=1;
  }
  return data_valid;
}