test/arduino/DS18x20_over_bluetooth/DS18x20_over_bluetooth.ino

// Basic Bluetooth sketch HC-06_01
// Connect the Hc-06 module and communicate using the serial monitor
//
// The HC-06 defaults to AT mode when first powered on.
// The default baud rate is 9600
// The Hc-06 requires all AT commands to be in uppercase. NL+CR should not be added to the command string
//
 
 
#include <SoftwareSerial.h>

#define INFO 1

//pins
const int tmp_sens = 7  // DS18x20 is on pin 7 (a 4.7K resistor is necessary)

// Connect the HC-06 RX to the Arduino TX on pin 5.
// If DC is 5v RX should be connected through a voltage divider.
// Connect the HC-06 TX to the Arduino RX on pin 4. 
SoftwareSerial BTserial(5, 4); // RX | TX

OneWire  ds(7);
// This is 
byte addr[8];

#define INVALID_TEMP -1000.

struct TempSensor
{
  // DS18x20 is on pin 7 (a 4.7K resistor is necessary)
    OneWire  ds(7);
    byte addr[8];
    byte data[12];
    byte type_s;

    bool start()
    {
    }

protected:

    bool init_sensor()
    {
        if ( !ds.search(addr)) {
            Serial.println("Failed to find address for DS18x20.");
            ds.reset_search();
            delay(250);
            return false;
        }

#if INFO
        print_address( addr );
        Serial.println();
#endif

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

        // 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;
        }
    }

    void print_array( byte* arr, byte len )
    {
        byte i;
        for( i = 0; i < len; i++) {
            Serial.write(' ');
            Serial.print(add[i], HEX);
        }
    }

    void print_address()
    {
        Serial.print("ROM =");
        print_array( addr, 8 );
    }

    void print_data()
    {
      Serial.print("Data =");
      print_array( data, 9 );
    }
    
};

void setup()
{
    // We will use this for debug output.
    Serial.begin(9600);

    // HC-06 default serial speed is 9600
    BTserial.begin(9600);  
}



float read_temp(void)
{
  byte i;
  byte present = 0;
  byte type_s;
  byte data[12];
  float celsius;
  

  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();    
  }

  if (OneWire::crc8(data, 8) != data[8]) {
      print_data( data );
      Serial.print(" CRC=");
      Serial.print(OneWire::crc8(data, 7), HEX);
      Serial.println(" is not valid!");
      return;
  }

  // Convert the data to actual temperature
  // because the result is a 16 bit signed integer, it should
  // be stored to an "int16_t" type, which is always 16 bits
  // even when compiled on a 32 bit processor.
  int16_t 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);
    // at lower res, the low bits are undefined, so let's zero them
    if (cfg == 0x00) raw = raw & ~7;  // 9 bit resolution, 93.75 ms
    else if (cfg == 0x20) raw = raw & ~3; // 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;

#if INFO
  Serial.print("  Temperature = ");
  Serial.print(celsius);
  Serial.print(" Celsius.");
#endif

  return celsius;
}
 
void loop()
{
 
    // Keep reading from HC-06 and send to Arduino Serial Monitor
    if (BTserial.available())
    {  
        Serial.write(BTserial.read());
    }
 
    // Keep reading from Arduino Serial Monitor and send to HC-06
    if (Serial.available())
    {
        BTserial.write(Serial.read());
    }
 
}