Water Level Monitor for Pet Drinking Fountain

// This code is for the Ultrasonic Distance Sensor
//      This will measure the distance between the sensor and the water using a signal
//      that will be sent and will bounce back. If the distance is larger than allowed,
//      the photon will check with the Non-Contact Digital Liquid Sensor to verify that
//      the water is too low. The photon will send the distance to an Excel sheet to graph
//      the water level throughout the day.

/* Connections from Ultrasonic Distance Sensor to Photon
 *
 *                                     +-----+
 *                          +----------| USB |----------+
 *                          |          +-----+       *  |
 *                  Vcc-----| [*] VIN           3V3 [ ] |
 *                  Gnd-----| [*] GND           RST [ ] |
 *                          | [ ] TX           VBAT [ ] |
 *                          | [ ] RX  [S]   [R] GND [ ] |
 *                          | [ ] WKP            D7 [ ] |       
 *                          | [ ] DAC +-------+  D6 [ ] |      
 *                          | [ ] A5  |   *   |  D5 [ ] |       
 *                          | [ ] A4  |Photon |  D4 [ ] |     
 *                          | [ ] A3  |       |  D3 [*] |-----Trig      
 *                          | [ ] A2  +-------+  D2 [*] |-----Echo       
 *                          | [ ] A1             D1 [ ] |       
 *                          | [ ] A0             D0 [ ] |
 *                          |                           |
 *                           \    []         [______]  /
 *                            \_______________________/
 *
 *
 */
 

// Identify Pins Used and Variables
    
    const int TriggerPin = D3;
    const int EchoPin = D2;
    int LED = D7;
    int WaterLevel;
    int Duration;
    
    
void setup() {
    
    Serial.begin(9600);
    
// Digital Pin Input/Output
    pinMode(TriggerPin, OUTPUT);
    pinMode(EchoPin, INPUT);
    pinMode(LED, OUTPUT);
    
// Subscribe to Gravity Sensor Code
    Particle.subscribe("myphoton", Water_Check);

// Subscribe to IFTTT Applet that will publish data to Google Sheets
    Particle.subscribe("Water_Level", myWaterHandler, MY_DEVICES);
}

void myWaterHandler(const char *event, const char *data) {
// Handles Integration
}

void loop() {

// Begin with Trigger Pin Off for 5 Microseconds
    digitalWrite(TriggerPin, LOW);
    delayMicroseconds(2);
    
// Send the Signal for 15 Microseconds and Then Turn Off
    digitalWrite(TriggerPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(TriggerPin, LOW);
    
// Convert Time (in MICROseconds)
    Duration = pulseIn(EchoPin, HIGH);
    int WaterLevel = Duration * (0.034/2); 
    String Distance = String(Duration*0.034/2);
    
// Trigger the integration
    Particle.publish("Water_Level", Distance);
    
// Wait 60 seconds
    delay(60000);
    digitalWrite(LED, LOW);    // Turn OFF the LED
    delay(30000); 
}

void Water_Check (const char *event, const char *data) {
// Check Water Level with Gravity Photon
    
    /* This is where photons communicate both ways.
       Echo_boi photon receives the Boolean response from myphoton saying whether the water
       is above or below the sensor. Echo_boi then checks to see if the water level it detected
       is also above or below designated limit. It will send a response agreeing that the
       either the pets need water or that the water level is good. */
    
    // If water is low (water line below gravity non-contact sensor)
    // and water level is below 6.5 (obtained through trial and error),
    // send message to Nick's photo agreeing water is needed. 
    if (strcmp(data, "waterLOW") == true && WaterLevel > 6.5) {
        char *message1 = "Need Water";
        Particle.publish("myphoton", message1, 20); // Publishing to Nick's photon
        Serial.println("Need Water");
        digitalWrite(LED, HIGH);
        delay(1500);
        digitalWrite(LED, LOW);
    }
       
    // If water  and water level is below 6.5 (obtained through trial and error),
    // send message to Nick's photo agreeing water is needed.
    else if (strcmp(data, "allclear") == true && WaterLevel < 6.5) {
        char *message2 = "I Good";
        Particle.publish("myphoton", message2, 20); // Publishing to Nick's photon
        Serial.println("I Good");
        digitalWrite(LED, HIGH);
        delay(1500);
        digitalWrite(LED, LOW);
        
    }
    
}