MyWater Fountain Controlled by Particle Photon and Blynk

// MyFountain / MySpringbrunnen v1.0 - Ingo Lohs
// Liest Temperatur & Feuchte und ein Relay schaltet entsprechend einen Zimmerspringbrunnen zur Befeuchtung ein, sobald der Schwellwert unterschritten wurde.
// Blynk: 2x Gauge (Temp V6, Humi V5), 1x Button for Relay V3, 1x History Graph with bindings on V6, V5, V4, 1x Slider to change Humi-Threshold V2

// Verbesserungen:
// Abschaltung während eines bestimmten Nachtfensters - der Motor der Pumpe kann unter Umständen zu einer Störung des Schlafs führen
// https://community.particle.io/t/sleep-mode-explained-using-code-samples/21173/4
// Lösung mit System.Sleep zwischen einer Auswahluhrzeit von bis.

// Wie in Wohnräumen, wo sich der Bewohner meist sitzend für mehrere Stunden aufhält, sollte auch im Arbeitszimmer beziehungsweise im Büro die
// Luftfeuchtigkeit zwischen 40 und 60 % liegen. Eine Raumfeuchtigkeit von 50 % ist für die Gesundheit des Menschen ideal.


#include <Adafruit_DHT.h>
#include <blynk.h>

// Relay is a LOW LEVEL: action is on LOW!!! connectet on 3,3V

    int baudrate = 9600;              // Serial Monitor 
    #define relayPin D4               // SIGNAL from Relay
    #define internalLED D7            // internal Device LED from Spark Core or Particle Photon
    float humidity_threshold = 50.00; // if humidity DRY <= Thresshold then activate a pump to water a room-fountain
    
    // DHT parameters
    #define DHTPIN D5                 // what pin we´re connected to the DHT22
    #define DHTTYPE DHT22             // DHT 22 (AM2302)
    // DHT sensor
    DHT dht(DHTPIN, DHTTYPE);
    float temperature;
    float humidity;
    unsigned long lastmillis = 0;
    
    // You should get Auth Token in the Blynk App.
    // Go to the Project Settings (nut icon).
    char auth[] = "67c2b39a792e4ced863b41c8b62323e6";
    #define vRelayBtn V3
    unsigned int vRelayStatus; // global var
    #define vThresholdSlider V2

// *********    

    BLYNK_WRITE(vRelayBtn) {     // Blynk app WRITES button status to server
    vRelayStatus = param.asInt();
    if(vRelayStatus == 1){
    digitalWrite(relayPin, LOW);
    digitalWrite(internalLED, HIGH); // internal LED on
    Serial.println("Relay is now ON");    
    }
    else {
    digitalWrite(relayPin, HIGH); 
    digitalWrite(internalLED, LOW); 
    Serial.println("Relay is now OFF");   
    }
    }

// *********    

    BLYNK_WRITE(vThresholdSlider)     // Blynk app WRITES Slider widget (0...100) on V2
    {
    humidity_threshold = param.asInt();
    Serial.println("******************************");    
    Serial.print(humidity_threshold);    
    Serial.println(" % = new Humidity Threshold");    
    Serial.println("******************************");    
    }
    
// *********  

    void setup() 
    {
      Serial.begin(baudrate); // Serial Debug Console: CMD - particle serial monitor --follow on Windows or MAC: Terminal - ls /dev/tty.* - screen /dev/tty.usbmodem1411
      while(!Serial); //Waiting for Serial connection
      pinMode(relayPin, OUTPUT); //Set pin D4 as an OUTPUT
      pinMode(internalLED, OUTPUT); //Set pin D7 as an OUTPUT
      digitalWrite(relayPin, HIGH); // Relay off - no pump at start
      digitalWrite(internalLED, LOW); // internal LED off
      delay(5000); // lets the DHT sensor settle setup 
      Blynk.begin(auth); // Blynk magic starts here
      dht.begin(); // Start DHT sensor
    }

// *********    

    void loop() 
    {
    Blynk.run();    
//    Blynk.virtualWrite(V4, humidity_threshold); 
//    !!! http://docs.blynk.cc/#troubleshooting-flood-error  
//    DO NEVER in LOOP!

            // DHT22 is a slow sensor - update in 2 sec intervals
            if ((millis() - lastmillis) > 2000) {
                lastmillis = millis();
                readData();
                executeRelay();
                update_HumiThreshold();
            }
    }

// *********    

    void readData()
    {
        // Temp measurement - in this case optional
      temperature = dht.getTempCelcius(); // dht.getTempFarenheit(); change if you like 
      Serial.print(temperature);
      Serial.println(" Grad Celsius");
        // Humidity measurement
      humidity = dht.getHumidity();
      Serial.print(humidity, 2); // #.##
      Serial.println(" % Feuchtigkeit");
      
        // You can send any value at any time.
        // Please don't send more that 10 values per second.
      Blynk.virtualWrite(V5, humidity);
      Blynk.virtualWrite(V6, temperature);
    }

// *********    
    
    void executeRelay()
    {
      if (vRelayStatus != 1) 
    {
      if ((humidity) <= humidity_threshold) 
        {
        Serial.println("Humidity in the room is too dry, we should activate the fountain.");
        digitalWrite(relayPin, LOW); // relay start
        digitalWrite(internalLED, HIGH);
        }
      else
        {  
        Serial.println("The room is wet enough, no need to active the fountain.");
        digitalWrite(relayPin, HIGH); // relay offline
        digitalWrite(internalLED, LOW);
        }
    }
    }
 
// *********       
    
    void update_HumiThreshold() 
    {
    Blynk.virtualWrite(V4, humidity_threshold); 
    }