// Name: Infrared and Ultrasound
// Purpose: This lab will explore both infra-red and ultrasonic sensors, by detecting the object with the given distances with an LED indicator. 
// Comment: Part 3 of Lab_7
// Author: Karl Edward Sarmiento 
// IP/Domain: MIT

// infrareds
int inf_pin = A1;                 // infrared analog pin
int inf_val = 0;                  // infrared value

// ultrasounds
int pin_trig = 8;                 // ultrasound trigger pin
int pin_echo = 7;                 // ultrasound echo pin
float us_val = 0;                 // ultrasound value

// LED
int LED_in = 33;
int LED_out = 32;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(pin_echo, INPUT);         // echo pin is set to input 
  pinMode(pin_trig, OUTPUT);        // trigger pin is set to output
  // LED
  pinMode(LED_in, INPUT);            // RED LED light
  pinMode(LED_out, OUTPUT);          // Ground LED
}

void loop() {
  // put your main code here, to run repeatedly:
  long dt;                                    // the duration of the pulse

  us_val = digitalRead(pin_echo);
  digitalWrite(pin_trig, LOW);
  delayMicroseconds(2);
  digitalWrite(pin_trig, HIGH);
  delayMicroseconds(10);                      // the trigger pulse duration
  digitalWrite(pin_trig, LOW);                     

  dt = pulseIn(pin_echo, HIGH);
  us_val = float (dt) * 0.034/2.0;            // calculation to get distance in cm
  Serial.print("Distance measured: ");
  Serial.println(us_val);                     // prints the "Distance measured: "

  inf_val = analogRead(inf_pin);
  Serial.print("Analog value: ");
  Serial.println(inf_val);                    // prints the analog value

  if (inf_val >= 9, us_val < 10.0){
    digitalWrite(LED_in, HIGH);
    delay(1000);
  } 
  else if (us_val > 99.0){                  // greater than 1m
    digitalWrite(LED_in, HIGH);
  } 
  else{                                      // turn off when it is less than 1m or less than 8 
    digitalWrite(LED_in, LOW);
    delay(1000);
  }
}