Brough Telecom

HADARS Greenhouse Thermometer.

---

/*
 * HADARS_Greenhouse_Thermometer.ino
 * 
 * Copyright 2018  <Chris Duckles aka G6KIA>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 * 
 * 
 */

#include <OneWire.h>
#include <DallasTemperature.h>
#include <LiquidCrystal.h>
///////////////////////////////////////////////
// select the pins used on the LCD panel      /
///////////////////////////////////////////////
//  LiquidCrystal lcd(RS, E, D4, D5, D6, D7) //
///////////////////////////////////////////////
 
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// Data wire is plugged into pin 8 on the Arduino
#define ONE_WIRE_BUS 8

// Setup a oneWire instance to communicate with any OneWire devices 
// (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);

int pause = 5000;        // 5000 milliseconds equals 5 second delay between temperature readings
float tempC = 0;         // Floating decimal point variable to store temperature reading
int tempCH = -1000;      // Integer variable to store Highest temperature reading. No decimal point.
int tempCL = 1000;       // Integer variable to store Lowest temperature reading. No decimal point.





void setup() {            // the setup function runs once when you press reset or power the board.

  Serial.begin(9600);     // Sets the data rate in bits per second (baud) for serial data transmission. 
                          // And starts communicating with the computer and on pin A0 RX and A1 TX.

  lcd.begin(16, 2);       // Starts the LCD display and set up display size 2 lines of 16 charictors.

  lcd.clear();                // Clear the display and set cursor to top left position.
  lcd.print("    HADARS");    // Print TXT to top line of display.
  lcd.setCursor(0,1);         // Move cursor to left position on the second line.
  lcd.print("  Thermometer"); // Print TXT to top line of display.
                // Remember computer 0 is always the first position so top line = 0 Bottom = 1.    
  
  sensors.begin();    // Start up the DS18b20 library

  delay(9000);        // wait 9 seconds so that users can read the display
}




void loop() {  // This is the main code, it run around the loop repeatedly:

  sensors.requestTemperatures();        // Send the command to get temperature
  tempC = sensors.getTempCByIndex(0);   // copy the current temperature into the Floating decimal point variable.
  Serial.println(tempC);                // print variable content to computer screen 

  if (tempCL > tempC) tempCL = tempC ;  // Test if the current temperature (tempC) colder than the coldest temperature
                                        // recorded in tempCL. If it is a new low store the new low in tempCL.

  if (tempCH < tempC) tempCH = tempC ;  // Test if the current temperature (tempC) hotter than the hottest temperature 
                                        // recorded in tempCH. If it is a new High store the new High in tempCH.
  
  lcd.clear();              // Clear the display. 
  lcd.setCursor(0,0);       // Set cursor to top left position.
  lcd.print("Hi");          // Print Hi on the top left of the display.
  lcd.setCursor(14,0);      // Move the cursor position top line second right position.
  lcd.print("Lo");          // Print Lo on the top right of the display.
  lcd.setCursor(5,0);       // Move the cursor to the left of centre of the top line.
  lcd.print(tempC);         // Print the current temperature to 2 decimal places.
 
  lcd.setCursor(0,1);       // Set cursor to bottom left position.
  lcd.print(tempCH);        // Print the hottest temperature recorded.
  lcd.write(223);           // Print the degree symbol.
  lcd.write("C");           // followed by a C.
  lcd.setCursor(12,1);      // Set cursor to position bottom 12
  lcd.print(tempCL);        // Print the coldest temperature recorded.
  lcd.write(223);           // Print the degree symbol.
  lcd.write("C");           // followed by a C.   

  delay(pause); // pause a few seconds as defined above between measurements.
            // if we don't pause the display will flicker and the DS18b20 wont have time to take an accurate reading.

/*  
    The code below is the same as above except that I have swapped the top and bottom line over so as to create some
    animation on the LCD to show that the system hasn't frozen or crashed.
*/

  sensors.requestTemperatures(); 
  tempC = sensors.getTempCByIndex(0);

  if (tempCL > tempC) tempCL = tempC ;
  if (tempCH < tempC) tempCH = tempC ;
  lcd.clear();
  lcd.setCursor(0,1);
  lcd.print("Hi");
  lcd.setCursor(14,1);
  lcd.print("Lo");
  lcd.setCursor(5,1);
  lcd.print(tempC);

  lcd.setCursor(0,0);
  lcd.print(tempCH);
  lcd.write(223); 
  lcd.write("C"); 
  lcd.setCursor(12,0);
  lcd.print(tempCL);
  lcd.write(223); 
  lcd.write("C");   
  delay(pause);
}