// Coded by J.Drage, 20-Feb-2022

STARTUP(System.enableFeature(FEATURE_RETAINED_MEMORY)); 
SYSTEM_THREAD(ENABLED); 
SystemSleepConfiguration config;

//-------------------------------------------------------------------------- 
// Define Boron pins:
//--------------------------------------------------------------------------
#define WLsensor_power D2 // Pin D2 powers the water level sensor on 
#define WLsensor_data D3 // Pin D3 is data output from the water level sensor

//-------------------------------------------------------------------------- 
// Variables to be entered by user
//--------------------------------------------------------------------------
int MeasureTime=86400000; // Time between water level measurements; entered by user (milliseconds)
int ConnectTime=120000; // Time allowed for Particle Boron to connect to the cloud before going back to sleep; should not be less than 90000; entered by user (milliseconds)

double Datum=10; // Datum elevation; typically top of well casing is used; entered by user (metres)
double HangDown=0; // Distance from datum to sensor; entered by user (metres)

//-------------------------------------------------------------------------- 
// Variables NOT entered by user
//--------------------------------------------------------------------------
int MeasureTime2=(MeasureTime-60000); // Subtract 60000 milliseconds from MeasureTime to account for time needed to connect to the cloud; this keeps the measurement time to about the same time each day 
double WLSensorValue=0; // Reading from water level sensor (mm)
double Depth=0; // Depth to water; measured by the sensor and then converted from mm to m (metres)
double GWelevation=0; // Water table elevation; calculated by code (metres)




void setup() {
//--------------------------------------------------------------------------
// Configure pins on the Boron 
//--------------------------------------------------------------------------
pinMode(WLsensor_power, OUTPUT);
pinMode(WLsensor_data, INPUT);
Serial.begin(9600);
PMIC().disableCharging();
config.mode(SystemSleepMode::ULTRA_LOW_POWER).duration(MeasureTime2);
}





void loop() {
//--------------------------------------------------------------------------
// Check to see if Boron is connected to the cloud, if not then go to sleep to preserve the batteries 
//--------------------------------------------------------------------------
restart:
if( !Particle.connected() ) { 
    Particle.connect();
if ( !waitFor(Particle.connected, ConnectTime) ) {
    System.sleep(config);
    goto restart;
    }
}
//-------------------------------------------------------------------------- 
// Read the water level from the sensor 
//--------------------------------------------------------------------------
digitalWrite(WLsensor_power, HIGH);
delay(1s);
WLSensorValue = pulseIn(WLsensor_data, HIGH);
digitalWrite(WLsensor_power, LOW);
Depth = (WLSensorValue/1000);
GWelevation = (Datum-HangDown-Depth);

//--------------------------------------------------------------------------
// Check to see if the water depth is out of sensor range and if so, go to sleep without reporting the result; sensor range is 0.3-5m (5m model) or 0.5-10m (10m model)
//--------------------------------------------------------------------------
if (Depth<0.31) { 
    delay(2s);
    System.sleep(config);
    goto restart;
}
if (Depth>4.99) { 
    delay(2s);
    System.sleep(config);
    goto restart;
}

//-------------------------------------------------------------------------- 
// Send the water level data to ThingSpeak.com 
//--------------------------------------------------------------------------
Particle.publish("Insert_Webhook_Name_Here", String(GWelevation, 2), PRIVATE);
delay(2s);
System.sleep(config);
goto restart;
}