Arduino 温度传感器DS18B210实验

安装OneWire（单总线）库

#include <Arduino.h>
#include <OneWire.h>

#define DebugSerial Serial // 用于把数据通过串口界面返回

OneWire ds(2);  // 连接arduino 引脚2

#include <LiquidCrystal_I2C.h>
#include <Wire.h>
LiquidCrystal_I2C lcd(0x27, 16, 2); // set the LCD address to 0x27 for a 16 chars and 2 line display

float tempBuffer = 0;

void setup()
{
  DebugSerial.begin(9600);	// 设置通讯的波特率为9600
  DebugSerial.println("hello");  // 发送的内容
  DebugSerial.println("chanpinxue.cn"); // 发送的内容

  lcd.init(); // lcd初始化
  lcd.backlight(); // 开启lcd背光灯
  lcd.print("chanpinxue.cn"); // 输出内
}

void loop()
{
  tempBuffer = readDs18b20();

  DebugSerial.print("TEMP = ");
  DebugSerial.println(tempBuffer);

  lcd.setCursor(0, 0);
  lcd.print("TEMP = ");
  lcd.print(tempBuffer);
  lcd.print(" C  ");

  delay(500);
}

// 读取温度
float readDs18b20()
{
  byte i;
  byte present = 0;
  byte type_s;
  byte data[12];
  byte addr[8];
  float celsius, fahrenheit;

  if ( !ds.search(addr)) {
    // Serial.println("No more addresses.");
    // Serial.println();
    ds.reset_search();
    delay(250);
  }

  if (OneWire::crc8(addr, 7) != addr[7]) {
    //Serial.println("CRC is not valid!");
    return 0;
  }
  Serial.println();

  // the first ROM byte indicates which chip
  switch (addr[0]) {
    case 0x10:
      //    Serial.println("  Chip = DS18S20");  // or old DS1820
      type_s = 1;
      break;
    case 0x28:
      //    Serial.println("  Chip = DS18B20");
      type_s = 0;
      break;
    case 0x22:
      //    Serial.println("  Chip = DS1822");
      type_s = 0;
      break;
    default:
      //    Serial.println("Device is not a DS18x20 family device.");
      return 0;
  }

  ds.reset();
  ds.select(addr);
  ds.write(0x44, 1); // start conversion, with parasite power on at the end

  delay(1000); // maybe 750ms is enough, maybe not
  // we might do a ds.depower() here, but the reset will take care of it.

  present = ds.reset();
  ds.select(addr);
  ds.write(0xBE); // Read Scratchpad

  for ( i = 0; i < 9; i++) { // we need 9 bytes
    data[i] = ds.read();
    //Serial.print(data[i], HEX);
    //Serial.print(" ");
  }
  //  Serial.print(" CRC=");
  //  Serial.print(OneWire::crc8(data, 8), HEX);
  //  Serial.println();

  // convert the data to actual temperature

  unsigned int raw = (data[1] << 8) | data[0];
  if (type_s) {
    raw = raw << 3; // 9 bit resolution default
    if (data[7] == 0x10) {
      // count remain gives full 12 bit resolution
      raw = (raw & 0xFFF0) + 12 - data[6];
    }
  }
  else {
    byte cfg = (data[4] & 0x60);
    if (cfg == 0x00) raw = raw << 3;  // 9 bit resolution, 93.75 ms
    else if (cfg == 0x20) raw = raw << 2; // 10 bit res, 187.5 ms
    else if (cfg == 0x40) raw = raw << 1; // 11 bit res, 375 ms
    // default is 12 bit resolution, 750 ms conversion time
  }
  celsius = (float)raw / 16.0;
  fahrenheit = celsius * 1.8 + 32.0;

  return celsius;
}