for emmiasim67 (fiverr)

/*
  infraredSensor LOW = detection
  metalSensor HIGH = detection
  pplasticSensor LOW = detection
  /------------------------------------------------------------------------/
  Truth Table
  1 = DETECT 0 = NO_DETECT
  Please don't get this confused with the actual sensor input

                M   Pl  M  Pa   n
  IR SENSOR      |1| |1| |1| |1| |0|
  PLASTIC SENSOR |1| |1| |0| |0| |0|
  METAL SENSOR   |1| |0| |1| |0| |0|

  M = Metal       - 1 1 1
  Pl = Plastic    - 1 1 0
  Metal           - 1 0 1
  Pa = Paper      - 1 0 0
  null            - 0 0 0
  /------------------------------------------------------------------------/

*/

/*Charge duration CHANGE THESE*/
const int metalChargeDuration = 0 * 1000;
const int plasticChargeDuration = 10 * 1000;
const int paperChargeDuration = 0 * 1000;




/*Sensor pins*/
const int plasticSensorPin = 2;
int plasticSensorValue;

const int metalSensorPin = 3;
int metalSensorValue;

const int infraredSensorPin = 5;
int infraredSensorValue;

const int relayModule = 6;

/*Conditions*/
uint8_t IR_DETECT = LOW;
uint8_t IR_NO_DETECT = HIGH;

uint8_t P_DETECT = LOW;
uint8_t P_NO_DETECT = HIGH;

uint8_t M_DETECT = HIGH;
uint8_t M_NO_DETECT = LOW;

uint8_t RELAY_ON = LOW;
uint8_t RELAY_OFF = HIGH;

unsigned long previousMillis = 0;

bool checkNow = false;

unsigned long lastPrint;



void setup()
{
  Serial.begin(115200);
  pinMode(plasticSensorPin, INPUT);
  pinMode(metalSensorPin, INPUT);
  pinMode(infraredSensorPin, INPUT);
  pinMode(relayModule, OUTPUT);
  digitalWrite(relayModule, RELAY_OFF);
  while (!Serial)
  {
    ; // Wait for serial to connect
  }
}

void loop()
{
  detectObjects();

}

void detectObjects()
{
  String materialKind;

  plasticSensorValue = digitalRead(plasticSensorPin);
  metalSensorValue = digitalRead(metalSensorPin);
  long chargeTime;
  int servoDegree;

  if (infraredSensorValue == IR_DETECT)
  {
    if ((plasticSensorValue == P_DETECT && metalSensorValue == M_DETECT) || (plasticSensorValue == P_NO_DETECT && metalSensorValue == M_DETECT))
    {
      chargeTime = 5000;
      servoDegree = 30;
      materialKind = "metal";

    }

    else if (plasticSensorValue == P_DETECT && metalSensorValue == M_NO_DETECT)
    {
      chargeTime = 4000;
      servoDegree = 40;
      materialKind = "plastic";

    }
    else if (plasticSensorValue == P_NO_DETECT && metalSensorValue == M_NO_DETECT)
    {
      chargeTime = 2000;
      servoDegree = 60;
      materialKind = "paper";
    }
    else
    {
      Serial.println("Invalid entry");
      materialKind = "invalid";
    }
  }
  checkMaterial(materialKind, chargeTime, servoDegree);

}

void checkMaterial( String &material,  long longVariable, int servoDegree)
{
  //Serial.println(material + " is detected charge time is " + chargeDuration + " servo degree is" + servoDegree);

  if (millis() - lastPrint >= 1000 && longVariable >= 1000) {
    lastPrint = millis();
    longVariable = longVariable - 1000;
    Serial.println(timeSort(longVariable));
  }
}

void storeValue(char* to, int val, char behind) {
  *to++ = '0' + val / 10;
  *to++ = '0' + val % 10;
  *to++ = behind;
}
char* timeSort(unsigned long num) {
  static char Buffer[10];
  int totalsec = num / 1000; //gives the total number of seconds
  int totalmin = totalsec / 60;
  int totalhour = totalmin / 60;
  storeValue(Buffer, totalhour, ':');
  storeValue(Buffer + 3, totalmin % 60, ':');
  storeValue(Buffer + 6, totalsec % 60, 0);
  return Buffer;
}