// EME3153   Ex6 Q2
// Student: Alan Lee
// Student ID: 250258181
// Class: 1B  (EG114403)
// Wokwi:  https://wokwi.com/projects/447285956035118081

#define LED_Out_Pin 25
#define SW_In_Pin 15
#define VR_In_Pin 36

int VRvalue;
int pastVRvalue;
int timea = 0;
int timeb = 0;
int textat = 0;
int textbt = 0;
int textct = 0;
int lighta = 0; 
int lightperiod = 200; // first ms

float lighttype = 0.5; // Range : 0 - 1
int textperiod = 10000;
int maxperiod = 1000;
int minperiod = 200;

void setup()
{
  Serial.begin(115200);

  pinMode(LED_Out_Pin, OUTPUT);
  pinMode(SW_In_Pin, INPUT_PULLUP);
}

void loop()
{
  VRvalue = analogRead(VR_In_Pin);
  if (pastVRvalue != VRvalue) {
    textbt = 1;
    timeb = 0;
  }
  pastVRvalue = VRvalue;
  VRvalue = map(VRvalue, 0, 4095, maxperiod, minperiod);
  lightperiod = VRvalue;
  
  if (digitalRead(SW_In_Pin))
  {
    if (lighta == 1) {
      digitalWrite(LED_Out_Pin, HIGH);
    } else if (lighta == 0) {
      digitalWrite(LED_Out_Pin, LOW);
    }
    if ( lighta == 1 && timea >= (lightperiod * lighttype)) {
      lighta = 0;
      timea = 0;
    } else if ( lighta == 0 && timea >= (lightperiod * (1 - lighttype))) {
      lighta = 1;
      timea = 0;
    }
    textct = 0;
  }
  else
  {
    digitalWrite(LED_Out_Pin, LOW);
    if (textct == 0) {
      texta();
      Serial.print("Minimum period: ");
      Serial.print(minperiod);
      Serial.print(" ms");
      Serial.print("\tMaximum period: ");
      Serial.print(maxperiod);
      Serial.println(" ms");
      textct = 1;
    }
    timea = 0;
    timeb = 0;
    lighta = 1;
  }

  if (textbt == 1 && timeb >= 500) {
    texta();
    textbt = 0;
    timeb = 0;
  } else if (textbt == 0 && timeb >= textperiod) {
    texta();
    textbt = 0;
    timeb = 0;
  }
  timea++;
  timeb++;
  delay(1);
}

void texta() {
  Serial.println("=======================================================");
  Serial.print("Raw Sensor reading: ");
  Serial.print(pastVRvalue);
  Serial.print("\tLED light period: ");
  Serial.print(lightperiod);
  Serial.println(" ms");
}