// This Example  demonstrates the operation of an IoT device with artificial intelligence to control a passive water heater.
// The device is based on the principle of measuring the RMS value of the mains voltage, 
//   analyzing the data and deciding when to switch on the heater, for how long to run during the hours of least load on the mains. 
// The device scheme includes a microcontroller of the ECP32 series, a module for measuring AC voltage from 0 to 250 volts, 
//   for example ZMPT101B module. 
// The ZMPT101B module is combined with a simple AC/DC rectifier.
// In this case, it is not necessary to use a software algorithm for reading and averaging for RMS.
// The DC voltage value of the rectifier output is in linear dependent with input RMS and can be used easy.
// For input voltages other than sinusoidal, the correction factor must be calculated with a new calibration.
// Dont forget to include NTPClient from Library Manager
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

// Time stamp part
#include <WiFi.h>
#include <NTPClient.h>
#include <WiFiUdp.h>

// Replace with your network credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Define NTP Client to get time
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);

// Variables to save time
String formattedTime;
String timeStamp;
unsigned long TimeUpdPeriod = -10000;   // За да сработи първия път
float HeaterOn = 0;  // Време за работа на бойлера
int HeaterReady = 0;
// ENd OF Time stamp part

// RMS measurement part
        int decimalPrecision = 2;                  // decimal places for all values shown in LED Display & Serial Monitor

        int VoltageAnalogInputPin = 32;            // Which pin to measure voltage Value
        int HeaterContolPin = 33;                   // Pin to HeaterContol
        float voltageSampleRead  = 0;               // to read the value of a sample in analog including
        float voltageLastSample  = 0;               // to count time for each sample.
        float voltageSampleSum   = 0;               // accumulation of sample readings 
        float voltageSampleCount = 0;               // to count number of sample. 
        float RMSVoltageMean ;                      // analog value
        float FinalRMSVoltage;                      // final voltage value
        float AdjustRMScoeff = 12.4;                // Conversion factor = Read level from GPIO/Iput voltage RMS
        int VoltageTrigerLevel = 220;               // Minimum voltage level to switch-On the heater.
 // END of RMS measurement part       
 
void setup() {

// Initialize Serial Monitor
    Serial.begin(115200);                            // In order to see value in serial monitor 
        pinMode(VoltageAnalogInputPin, INPUT);       // Define pins state
        pinMode(HeaterContolPin,      OUTPUT);
        
// Real time part connection to NTP server
Serial.print("Connecting to ");
Serial.println(ssid);

WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
// Print local IP address and start web server
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());

// Initialize a NTPClient to get time
timeClient.begin();

// Set offset time in seconds to adjust for your timezone, for example:
// GMT +1 = 3600  GMT -1 = -3600  GMT 0 = 0
timeClient.setTimeOffset(10800);                  //Sofia +3 = +10800
}

     
void loop(){ 
   
if(millis() >= TimeUpdPeriod + 10000 ) {         // every 10 second taking 1 reading of Time
          
   if(!timeClient.update()) {
     timeClient.forceUpdate();
     }
     
// The formattedTime comes with the following format: 16:00:13   We need to extract the Hour
formattedTime = timeClient.getFormattedTime();
// Extract hour
int splitT = formattedTime.indexOf(":");

Serial.print("Time is: ");
Serial.print(formattedTime);
// Extract hour only
timeStamp = formattedTime.substring(0, splitT);
Serial.print(",   Hour only is: ");
Serial.println(timeStamp);
TimeUpdPeriod = millis();
voltageLastSample = micros();
}

// Monitoring and turning on the water heater

  if( timeStamp >= "13" || timeStamp <= "06" ) {            //  || - Logical "OR"
    while (voltageSampleCount < 2000){                      // Wait for 2000 samples
 // while ((micros() <= voltageLastSample + 1000 ) ){       // Wait for samples for 1 millisec. (must be more than 1000)
 
 // RMS mesurement part - get voltage of GPIO 32 
            if(micros() >= voltageLastSample + 1000 )       // every 1 milli second taking 1 reading 
            {
           // voltageSampleRead = (analogRead(VoltageAnalogInputPin)/AdjustRMScoeff);  //Wen we use real hardware
            voltageSampleRead = (random(2700,2800)/AdjustRMScoeff);  //We simulate an input between 218 and 226V for demo module
           
            voltageSampleSum = voltageSampleSum + voltageSampleRead ;   // accumulate total analog values for each sample readings
            voltageSampleCount = voltageSampleCount + 1;                // to move on to the next following count 
            voltageLastSample = micros() ;                              // to reset the time again so that next cycle can start again 
            }
  }

            RMSVoltageMean = voltageSampleSum/voltageSampleCount;      // calculate average value of all sample readings taken
            Serial.print(" The Voltage RMS value is: ");
            Serial.print(RMSVoltageMean,decimalPrecision);
            Serial.print(" V. Average from samples -  ");
            Serial.println(voltageSampleCount);
            voltageSampleSum =0;                                       // to reset accumulate sample values for the next cycle 
            voltageSampleCount=0;                                      // to reset number of sample for the next cycle 

   
// Switch Heater On or Off

           if (( RMSVoltageMean > VoltageTrigerLevel || timeStamp >= "04" && timeStamp <= "06") && HeaterReady == 0 )
           {
              Serial.print(" Heater is On for 20 sec. Warm-up period *");
              digitalWrite(HeaterContolPin, HIGH);         // Start  the heating
              HeaterOn = millis();
              while ( millis() <= HeaterOn + 20000 )       // 7200000  is 2 hours in milliseconds. 2 hours heating
              {
               delay(1000);
               Serial.print("*");
              }
              Serial.println();
              Serial.println(" Heater is ready. Now is Off.");
              digitalWrite(HeaterContolPin, LOW);         // Stop  the heating
              Serial.println();  
              HeaterReady = 1;
           }

            if ( HeaterReady == 1 )
              {
               Serial.println(" Waiting for the next power-on period / For the demo - 30 seconds");
               Serial.println(); 
           //    while ( timeStamp <= "07" || timeStamp >= "22")      
           //        {
                   delay(30000);    // 30 seconds delay
           //        }
                   HeaterReady = 0;
              }

          } // End of check for 22.00-06.00 o'clock 
}