greenhouseheating/greenhouseheating.ino

// Greenhouse heating system
#include <Arduino.h>
#include <Thread.h>                    // ArduinoThread
#include <DHT.h>                       // DHT Sensor Library by Adafruit 1.2.3 (!!! 1.3 not working)
#include <DS1307RTC.h>                 // A basic DS1307 library that returns time as a time_t
#include <SevenSegmentExtended.h>      // Extended TM1637 library https://github.com/bremme/arduino-tm1637

const byte PIN_CLK = 2;                // Define CLK pin (for 4-Digit Display)
const byte PIN_DIO = 3;                // Define DIO pin (for 4-Digit Display)
const byte button = 4;
const byte relay = 5;                  // Relay PIN
#define DHTPIN 6                       // PIN DHT

DHT dht(DHTPIN, DHT11);                // DHT-22 - AM2302 init
SevenSegmentExtended display(PIN_CLK, PIN_DIO);

int minTemp = 11;                      // Minimum temperature for relay (on)
int maxTemp = 14;                      // Maximum temperature for relay (off)
long relayWorkingTime = 600000;        // 10min - minimun working time

int tempThreadMs = 10000;              // checkTemp thread interval
int buttonThreadMs = 200;              // pressButton thread interval
int buttonState = 0;                   // Button state
int buttonView = 0;                    // Button viewing state
int relayState = 0;                    // Relay state
long previousRelayChanged = 0;         // Last time relay state changed
long buttonPressed = 0;                // Button ms pressed counter
long previousButtonMillis = 0;         // Last time button pressing
long buttonInterval = 10000;           // Interval for highlighting 4-Digit Display after pressing button

// Threads:
Thread pressButtonThread = Thread();   // Create thread for button state checking
Thread checkTempThread = Thread();     // Create thread for temperature state checking

void setup() {
  Serial.begin(9600);                  // Initializes the Serial connection @ 9600 baud for debug
  serStr("starting setup...");
  display.begin();                     // Initializes the display
  display.setBacklight(100);           // Set the brightness to 100 %
  display.print("INIT");               // Display INIT on the display
  while (!Serial);                     // Wait until Arduino Serial Monitor opens
  setSyncProvider(RTC.get);            // The function to get the time from the RTC
  if(timeStatus()!= timeSet) 
    Serial.println("Unable to sync with the RTC");
  else
    Serial.println("RTC has set the system time");
  dht.begin();
  pinMode(button, INPUT);
  pinMode(relay, OUTPUT);
  digitalWrite(relay, LOW);
  // Button state cheking thread:
  checkTempThread.onRun(checkTemp);
  checkTempThread.setInterval(tempThreadMs); // Interval for checking temperature
  pressButtonThread.onRun(pressButton);
  pressButtonThread.setInterval(buttonThreadMs); // Interval for checking button pressing
  delay(5000);                         // 5 second delay before display off and setup complete
  display.off();
  serStr("...setup finished");
}

void loop() {
  // Threads init:
  if (pressButtonThread.shouldRun())
    pressButtonThread.run();
  if (checkTempThread.shouldRun())
    checkTempThread.run();
  // Check RTC.
  if (!(timeStatus() == timeSet)) {
    display.on();
    display.print("SET TIME");
    delay (10000);
  }
}

// Check temperature thread
void checkTemp() {
  unsigned long currentMillis = millis();
  if (((currentMillis - previousRelayChanged) > relayWorkingTime) || (previousRelayChanged == 0)) {
    float tempFloat;
    readDHTtemp(&tempFloat);
    int tempInt = (int)tempFloat;
    if ((tempInt < minTemp) && (relayState == 0)) {
      serStr("low temperature - heating on");
      digitalWrite(relay, HIGH);
      previousRelayChanged = currentMillis;
      relayState = 1;
    }
    if ((tempInt > maxTemp) && (relayState == 1)) {
      serStr("high temperature - heating off");
      digitalWrite(relay, LOW);
      previousRelayChanged = currentMillis;
      relayState = 0;
    }
  }
}

// Check button pressing thread
void pressButton() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousButtonMillis > buttonInterval) {
    previousButtonMillis = currentMillis;
    display.off();
  }
  if (digitalRead(button) == HIGH) buttonState = 1;
    else buttonState = 0;
  if (buttonState == 1) {
    buttonPressed=buttonPressed+200;
    if (buttonPressed > 5000) {
      if (relayState == 0) {
        serStr("long press button - 5 sec - heating on");
        digitalWrite(relay, HIGH);
        relayState = 1;
        previousRelayChanged = currentMillis;
        buttonPressed = 0;
      } else {
        serStr("long press button - 5 sec - heating off");
        digitalWrite(relay, LOW);
        previousRelayChanged = currentMillis;
        relayState = 0;
        buttonPressed = 0;
      }
    }
    previousButtonMillis = currentMillis;
    display.on();
    if (buttonView == 0) {
      display.printTime(hour(), minute(), true);
    } else if (buttonView == 1) {
      float tempFloat;
      readDHTtemp(&tempFloat);
      int tempInt = (int)tempFloat;
      byte  rawData[4];
      if (tempInt == 0) {
        rawData[0] = B01000000; // dash
        rawData[1] = B01000000; // dash
      } else {
        rawData[0] = display.encode(tempInt / 10);
        rawData[1] = display.encode(tempInt % 10);
      }
      rawData[2] = B01100011;    // degree
      rawData[3] = display.encode('A') ;
      display.printRaw(rawData);
    } else if (buttonView == 2) {
      float humFloat;
      readDHThum(&humFloat);
      int humInt = (int)humFloat;
      byte  rawData[4];
      rawData[0] = display.encode('h');
      rawData[1] = display.encode('u');
      if (humInt == 0) {
        rawData[2] = B01000000; // dash
        rawData[3] = B01000000; // dash
      } else {
        rawData[2] = display.encode(humInt / 10);
        rawData[3] = display.encode(humInt % 10);
      }          
      display.printRaw(rawData);
    }
    if (buttonView < 2) buttonView += 1;
      else buttonView = 0;
  } else {
    buttonPressed = 0;
  }
}
 
// DHT Temperature
void readDHTtemp(float *a) {
  float t = dht.readTemperature();
  *a = t;
}
 
// DHT Humidity
void readDHThum(float *a) {
  float h = dht.readHumidity();
  *a = h;
}

// Send string to serial monitor with millis() counter and date/time
void serStr(const char* serString) {
  long currentTime = millis();
  String space = " ";
  String stringToPrint = currentTime + space + serString;
  Serial.println(stringToPrint);
  // RTC mark
  Serial.print("RTC time = ");
  Serial.print(hour());
  Serial.write(':');
  Serial.print(minute());
  Serial.write(':');
  Serial.print(second());
  Serial.print(", date (D/M/Y) = ");
  Serial.print(day());
  Serial.write('/');
  Serial.print(month());
  Serial.write('/');
  Serial.print(year());
  Serial.println();
}