#include <TM1637Display.h>

const int CLK = 13; // The ESP32 pin GPIO11 D2 connected to CLK
const int DIO = 12; // The ESP32 pin GPIO7 D1 connected to DIO

TM1637Display display(CLK, DIO); //set up the 4-Digit Display.


//define sound speed in cm/uS
#define SOUND_SPEED 0.034

const int trigPin = 5;
const int echoPin = 18;

long duration;
float distanceCm;

void setup() {
  // put your setup code here, to run once:
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input

  Serial.begin(115200); // Starts the serial communication
  Serial.println("Hello, ESP32!");

  display.setBrightness(0x0a); //set the diplay to maximum brightness  
                             // Set brightness (0-7):
}

void loop() {
  // put your main code here, to run repeatedly:

  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate the distance
  distanceCm = round(duration * SOUND_SPEED/2);

  // Prints the distance in the Serial Monitor
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);

  display.showNumberDec(distanceCm); //Display the numCounter value
  
  delay(1000);
}