/* This is a program to control the water level in a sump. 
Using two pumps to remove water in conjunction with a level sensor.*/

#include <elapsedMillis.h> // Library to control Process Timer
#include <LowPower.h> // Library to control Sleep/idle Mode

int LevelSensor = A0; // Potentiometer Level Sensor Input
int Pump1 = 2; // Pump 1 Output
int Pump2 = 3; // Pump 2 Output
int Alarm = 8; // Alarm Output
boolean alternatePump = 1 ; // Boolean variable to swap pumps 

int potValue; // Potentiometer value level sensor

int LowWaterLevel = 1023*0.1; // Low water level
int HighWaterLevel = 1023*0.9; // High water level

elapsedMillis ProcessTimeElapsed; // Process Timer to control Program State

void setup ()
{
	Serial.begin(9600);
	pinMode(Pump1, OUTPUT);
	pinMode(Pump2, OUTPUT);
	pinMode(Alarm, OUTPUT);
}

void loop ()
{ 
	potValue = analogRead(LevelSensor); // Analogue read for Level Sensor (LOW & High Level) 

		if (potValue >= HighWaterLevel && alternatePump == 1 && digitalRead(Pump1) == LOW)
		// Water Level reaches High level, Boolean variable is True and Pump 1 is not running.
		if (ProcessTimeElapsed < 90000) // Process Timer is below 90 seconds
			{	
				digitalWrite(Pump2, HIGH); // Pump 2 Starts. 
				alternatePump = 0; // Boolean variable becomes false to alternate pump selection. 
				ProcessTimeElapsed = 0; // Process Timer is restarted at 0 seconds.
			}

		if (potValue >= HighWaterLevel && alternatePump == 0 && digitalRead(Pump2) == LOW)
		// Water Level reaches High level, Boolean variable is false and Pump 2 is not running. 
		if (ProcessTimeElapsed < 90000) // Process Timer is below 90 seconds
			{
				digitalWrite(Pump1, HIGH); // Pump 1 Starts. 
				alternatePump = 1; // Boolean variable becomes true to alternate pump selection.
				ProcessTimeElapsed = 0; // Process Timer is restarted at 0 seconds.
			} 

		if (ProcessTimeElapsed >= 30000 && ProcessTimeElapsed < 90000)
		// Process Timer has counted 30 Seconds and is below 90 Seconds - Both pumps run together. 
			{ 
				digitalWrite(Pump2, HIGH); // Pump 2 Starts if not previously running.
				digitalWrite(Pump1, HIGH); // Pump 2 Starts if not previously running.
			} 	
		
		if (ProcessTimeElapsed >= 60000 && ProcessTimeElapsed < 90000)
 		// Process Timer has counted 60 Seconds and is below 90 Seconds - Plant will alarm.
			{ 
				tone(8, 262, 90000); // Sump Pit Control Panel will alarm continuously.
			} 	

		if (ProcessTimeElapsed > 90000)
		// Process Timer has counted 90 Seconds - Plant will shutdown.  
			{ 
				digitalWrite(Pump2, LOW); // Pump 2 is shut down.
				digitalWrite(Pump1, LOW); // Pump 1 is shut down.
				noTone(Alarm); // Sump Put Control Panel will stop alarming.
			} 

		if (potValue <= LowWaterLevel)
		// Water level reaches low level. Plant will shutdown.  
			{ 
				digitalWrite(Pump2, LOW); // Pump 2 is shut down.
				digitalWrite(Pump1, LOW); // Pump 1 is shut down.
				noTone(Alarm); // Sump Put Control Panel will stop alarming.
				ProcessTimeElapsed = 0; // Process Timer is set to 0 seconds.
	
				LowPower.idle(SLEEP_1S, ADC_OFF, TIMER2_OFF, TIMER1_OFF, TIMER0_OFF,SPI_OFF, USART0_OFF, TWI_OFF); 
				// Plant switches to an idle state for 1 second, Low Power Mode to conserve power when water level is low.
  		} 
}