Sensitive Arduino Lightning Detector with Homemade Sensor

// Firmware for Blitz-o-shield Rev.1
// Firmwareversion: Rev.0
// Copyright F.R. 2019
// www.ramser-elektro.at
//
//
#include <Wire.h>

const bool SendFullDebugText = true;         // Send debug message over RS232?
const word RemoteImpulseTime = 000;           // Set how long the remote impulse will be

int LED_red = 12;      
int LED_yellow = 10;
int LED_green = 9;
int LED_strike = 13;

int PWM_pin = 11;
int REMOTE_pin = 7;

int AnalogIn = A0;

word ActValue;                                // Actual value of analog signal
float AverageValue;                           // Averange value
int Difference;                               // Difference value (AverageValue - ActValue)

word StrikeCount;                             // Actual strikecounter. Every strike 32 is added.
word WarnLevel = 255;                         // Actual warning level 
word Decay;                                    // Value, how much the warnlevel is decreased, if no activity

word InactivityTimer;                         // Timer for new PWM tune, if no activity

bool Blink;                                   // Helper for LED blinking

unsigned long PreviousRemoteMillis = 0;       // Helper for remote impulse

word PWM_DutyCycle;                           // Actual duty cycle for PWM
word PWM_Duty_Watchdog;                       // Helper for PWM Adjustment

unsigned long PreviousMillis = 0;             // Helper for 1 second cycle

void setup(){                                 // Assign the hardware setup 
 
  pinMode(LED_red, OUTPUT); 
  pinMode(LED_yellow, OUTPUT); 
  pinMode(LED_green, OUTPUT); 
  pinMode(LED_strike, OUTPUT); 
  pinMode(PWM_pin, OUTPUT); 
  pinMode(REMOTE_pin, OUTPUT); 
  Serial.begin(9600);
  analogReference(INTERNAL);                  // Set the reference voltage to 1.1 volt
  TunePWM();
}

void TunePWM(){                               // Setup the PWM and tune it
  if (SendFullDebugText){
    Serial.print("PWM duty cycle tuning started");
    Serial.print("\r\n");
  }  
  PWM_DutyCycle = 0;                          // First discharge the capaciators
  analogWrite(PWM_pin,PWM_DutyCycle);  
  digitalWrite(LED_green, HIGH);              // Set green LED = capaciator discharged
  delay(250);
                                 
  ActValue = analogRead(AnalogIn);            // Read dummy
  PWM_Duty_Watchdog = 0;                      // Reset watchdog
  
  while (ActValue < 1023){                    // Has analogue input reached the maximum?
    ActValue = analogRead(AnalogIn);          // Read analog input
    AverageValue = ActValue;                  // Preset avarange value
    PWM_DutyCycle = PWM_DutyCycle +1;         // Increase PWM level
    PWM_Duty_Watchdog = PWM_Duty_Watchdog +1; // Increase the PWM watchdog
    analogWrite(PWM_pin,PWM_DutyCycle);   
    delay(250);                               // Always wait a little time, to load the capacitors
    if (ActValue > 341){                      // Set yellow LED = ActValue  > 1/3 of maximum.
      digitalWrite(LED_yellow, HIGH);
    }
    if (ActValue > 682){                      // Set red LED = ActValue  > 2/3 of maximum.
      digitalWrite(LED_red, HIGH);
    }    
    if (PWM_Duty_Watchdog >= 255){            // Maximum PWM duty cycle reached. Something is wrong!!
      Blink = !Blink;                         // LED Blink Helper
      if (SendFullDebugText){
      Serial.print("Problem while adjust PWM Duty cycle. Maximum reached!!!");
      Serial.print("\r\n");
      }
      digitalWrite(LED_green, Blink);         // Blink all LED in endless loop
      digitalWrite(LED_yellow, Blink);
      digitalWrite(LED_red, Blink);
      digitalWrite(LED_strike, Blink); 
      delay(500);         
    }
    ActValue = analogRead(AnalogIn);          // Read analog input
    AverageValue = ActValue;                  // Preset avarange value
  }

  PWM_DutyCycle = (PWM_DutyCycle /3 ) * 2;
  analogWrite(PWM_pin,PWM_DutyCycle);
  digitalWrite(LED_strike, HIGH);           // Set white LED = Tune PWM successful
  delay(1000);
  digitalWrite(LED_green, LOW);
  digitalWrite(LED_yellow, LOW);
  digitalWrite(LED_red, LOW);
  digitalWrite(LED_strike, LOW);
  if (SendFullDebugText){
    Serial.print("PWM duty cycle tune successfull");
    Serial.print("\r\n");
  }  
}

void loop(){
  
  ActValue = analogRead(AnalogIn);            // Read in actual value
  AverageValue = AverageValue * 15;           // Calculate the averange value
  AverageValue = AverageValue + ActValue;
  AverageValue = AverageValue / 16;   
  Difference = AverageValue - ActValue;
  
if (Difference >= 15){                        // STRIKE !!!
  digitalWrite(LED_strike, HIGH);
  delay(50);
  digitalWrite(REMOTE_pin, HIGH);  // Set remote action
  
  PreviousRemoteMillis = millis();
  StrikeCount = StrikeCount + 32;
  if (StrikeCount >= 255){                    //  More then 8 Strikes in 1 Second ?
    StrikeCount = 255;                        //  More then 8 strikes per second don't happen naturaly
  }  
}
else{
  digitalWrite(LED_strike, LOW);
}

if ((millis() - PreviousRemoteMillis >= RemoteImpulseTime) and (digitalRead(REMOTE_pin))){  // Remote impulse time elapsed
  digitalWrite(REMOTE_pin, LOW);
}

if (millis() - PreviousMillis >= 1000){       // 1 Second elapsed  
  Blink = !Blink;                             // LED Blink Helper
  
  if (StrikeCount > 32){                      // At leased 2 strikes in one second
    WarnLevel = WarnLevel + StrikeCount;      // Increase Warnlevel
  }  
  
  Decay = highByte(WarnLevel);
  WarnLevel = WarnLevel - Decay;              //  Level decreasing

  if (WarnLevel < 1000){                      // No LED on
    digitalWrite(LED_green, LOW);
    digitalWrite(LED_yellow, LOW);
    digitalWrite(LED_red, LOW); 
  }
  if ((WarnLevel >= 1000) and (WarnLevel < 1500)){ // Green LED on
    digitalWrite(LED_green, Blink);
    digitalWrite(LED_yellow, LOW);
    digitalWrite(LED_red, LOW); 
  }
  if ((WarnLevel >= 1500) and (WarnLevel < 2500)){ // Yellow LED on
    digitalWrite(LED_green, LOW);
    digitalWrite(LED_yellow, Blink);
    digitalWrite(LED_red, LOW); 
  }
  if (WarnLevel >= 2500){                     // Red LED on
    digitalWrite(LED_green, LOW);
    digitalWrite(LED_yellow, LOW);
    digitalWrite(LED_red, Blink); 
  }
  if (WarnLevel >= 3000){                     // Maximum reached
    WarnLevel = 30000; 
  }
   
  if (SendFullDebugText == true){             // Send debugmessage over RS232
    // PWM;ActValue;AverangeValue;Difference;Warnlevel;Decay;Strikecount;
    Serial.print("PWM:");
    Serial.print(PWM_DutyCycle);
    Serial.print("  Actual:");
    Serial.print(ActValue);
    Serial.print("  Averange:");
    Serial.print(AverageValue);
    Serial.print("  Difference:");
    Serial.print(Difference);
    Serial.print("  Warnlevel:");
    Serial.print(WarnLevel);
    Serial.print("  Decay:");
    Serial.print(Decay);
    Serial.print("  Strikecount:");
    Serial.print(StrikeCount);
    Serial.print("\r\n");
  }

  if (Decay == 0){                            // No activity. Increase InactivityTimer
    InactivityTimer = InactivityTimer +1;
    if (InactivityTimer >= 3600){             // No activity for one hour. Tune PWM.
      TunePWM();
      InactivityTimer = 0;     
    }
  }

  StrikeCount = 0;                            // Reset strikecounter
  PreviousMillis = millis();                  // Save actual millis, for the next 1 second cycle
}
  
}