DS18B20Sensor.h

#pragma once
/*
ASensor - Sensor library. Can be used standalone or in conjunction with AWind library
Copyright (C) 2015-2018 Andrei Degtiarev. All right reserved

You can always find the latest version of the library at
https://github.com/AndreiDegtiarev/ASensor

This library is free software; you can redistribute it and/or
modify it under the terms of the MIT license.
Please see the included documents for further information.
*/
///DS18B20-Temperature sensor. To use this sensor OneWire library has to be installed from http://www.pjrc.com/teensy/td_libs_OneWire.html. Details to member functions see ISensor class documentation
class DS18B20Sensor : public ISensor
{
#ifndef DEMO_SENSORS
	OneWire  *ds;
#endif
	int _wire_index;
public:
	DS18B20Sensor(int port,int wire_index)

	{
#ifndef DEMO_SENSORS
		ds=new OneWire(port);
#endif
		_wire_index=wire_index;
	}
	virtual const __FlashStringHelper* Name()
	{
		return F("DS18B20");
	}
	virtual float LowMeasurementLimit()
	{
		return -50;
	}
	virtual float HighMeasurementLimit()
	{
		return 50;
	}
	virtual int Precission()
	{
		return 1;
	}
	virtual bool Measure(float & ret_data)
	{

#ifdef DEMO_SENSORS
		ret_data=(float)rand()/RAND_MAX*5+15;
		return true;
#else
		byte i;
		byte present = 0;
		byte type_s=0;
		byte data[12];
		byte addr[8];
		//byte addr[] = {0x28,0xB2,0x6F,0xA4,0x5,0x0,0x0,0x9B};
		float celsius, fahrenheit;

		bool isError=true;
		for(int i=0;i<_wire_index;i++)
		{
			for(int j=0;j<3;j++)
			{
				isError=!ds->search(addr);
				if(isError)
				{
					Serial.print(F("No more addresses:"));
					Serial.println(j);
					delay(250);
				}
				else
				{
					/*Serial.print("found ");
					Serial.print(i);
					Serial.println(_wire_index);*/
					break;
				}
			}
			if(isError)
				break;
		}
		if(isError)
		{
			ds->reset_search();
			return false;
		}
		/*Serial.print("ROM =");
		for( i = 0; i < 8; i++) {
		Serial.write(' ');
		Serial.print(addr[i], HEX);
		}
		Serial.println("");*/

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

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

		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

		/*Serial.print("  Data = ");
		Serial.print(present, HEX);
		Serial.print(" ");*/
		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
		// 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;
		fahrenheit = celsius * 1.8 + 32.0;
		/*Serial.print("  Temperature = ");
		Serial.print(celsius);
		Serial.print(" Celsius, ");
		Serial.print(fahrenheit);
		Serial.println(" Fahrenheit");*/
		ds->reset_search();
		if(!isnan(celsius))
		{
			ret_data=celsius;
#ifdef DEBUG_AWIND
			out<<F("DS18B20: ")<<ret_data<<endln;
#endif
			return true;
		}
#endif
		return false;
	}
};