AquaNiner Pet Hydration Monitor

/*This sketch shows the wiring of the photon for the non contact liquid level sensor.
 
                                       +-----+
 *                          +----------| USB |----------+
 *                          |          +-----+         |
 *          VCC (on sensor)-| [*] VIN           3V3 [ ] |
 *          GND (on sensor)-| [*] GND           RST [ ] |
 *                          | [ ] TX           VBAT [ ] |
 *                          | [ ] RX  [S]   [R] GND [ ] |
 *                          | [ ] WKP            D7 [ ] |       
 *                          | [ ] DAC +-------+  D6 [ ] |       
 *                          | [ ] A5  |   *   |  D5 [ ] |       
 *                          | [ ] A4  |Photon |  D4 [ ] |     
 *                          | [ ] A3  |       |  D3 [ ] |       
 *                          | [ ] A2  +-------+  D2 [ ] |       
 *                          | [ ] A1             D1 [*] |-Trig (on sensor)                
 *                          | [ ] A0             D0 [*] |-Echo (on sensor)         
 *                          |                           |
 *                           \    []         [______]  /
 *                            \_______________________/
 *
 *
 */

// intitializes the pins used in the program

const int triggerPin = D1;
const int echoPin = D0;
int light = D7;
int willswaterlevel;

// initialized the data that's coming in, long indicates a
// larger decimal number, int indicates an integer value
unsigned long duration;
int mydistance;


void setup() {

//establishes input and output for the digital pins

  pinMode(triggerPin, OUTPUT);

  pinMode(echoPin, INPUT);
  
  pinMode(light,OUTPUT);
  
// subscribes this particle to the other particle's code and sends the strings coming from that event
// to the program "H20_checker"

Particle.subscribe("ish2ook", H2O_checker);
  

}

void loop() {

//first to make sure that the trigger pin is off, we'll make it 
//low for 2 microseconds:

digitalWrite(triggerPin, LOW);
delayMicroseconds(2);

//next we'll send the signal for 10 microseconds and then turn 
//it off (this is the ultrasonic wave)

digitalWrite(triggerPin, HIGH);
delayMicroseconds(10);
digitalWrite(triggerPin, LOW);

//this gets the time (duration)which the HIGH pulse 
//was recieved and then
//converts it to distance, using
//the formula in this video:
//https://www.youtube.com/watch?v=ZejQOX69K5M&authuser=0
//note: duration is in microseconds

duration = pulseIn(echoPin, HIGH);

// once duration is aquired, it is converted into both a string and an integer using the following formula

willswaterlevel = duration*.035/2;

String mydistance = String(duration*.035/2);



//this just publishes the distance to Thingspeak

Particle.publish("mydistance", mydistance, PRIVATE);

delay(3000);


}

// this function, H20_checker,  takes the strings sent from the other photon's event and compares them to the distance data gathered from this particle

void H2O_checker(const char *event, const char *data)

{
/* Particle.subscribe handlers are void functions, which means they don't return anything.
They take two variables-- the name of your event, and any data that goes along with your event.

Since the input here is a char, we can't do

data=="waterLOW"
or
data=="waterLOW"

chars just don't play that way. Instead we're going to strcmp(), which compares two chars.
If they are the same, strcmp will return 0.
*/

// this is the situation where both sensors indicate water is needed

if (strcmp(data,"waterLOW")==0 && willswaterlevel > 30 ) {

Particle.publish("watercheck", "GIVE_FLUFFY_SOME H2O", 20);
digitalWrite(light, HIGH);
delay(5000);
digitalWrite(light, LOW);
}

// this is the situation where the other photon indicates the water needs to be filled, but this photon does not

else if (strcmp(data,"waterLOW")==0 && willswaterlevel < 30 ) {

Particle.publish("watercheck", "SENSORERROR", 20);
digitalWrite(light, HIGH);
delay(5000);
digitalWrite(light, LOW);

// this is the situation where both photons indicate an acceptable water level

}

else if (strcmp(data,"allclear")==0 && willswaterlevel < 30 ) {

Particle.publish("watercheck", "allclearwill", 20);
digitalWrite(light, HIGH);
delay(1000);
digitalWrite(light, LOW);

}

// this is the situation where the other particle indicates water is needed but this one does not

else {
    
Particle.publish("watercheck", "SENSORERROR2", 20);
// if the data is something else, don't do anything.
// Really the data shouldn't be anything but those two listed above.
digitalWrite(light, HIGH);
delay(5000);
digitalWrite(light, LOW);
}
}