#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <WiFi.h>
#include <ThingSpeak.h>

const int trigPin = 19;
const int echoPin = 18;

//define sound speed in cm/us
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration;
float distanceCm;
float distanceInch;

#define SECRET_SSID "Wokwi-Guest"
#define SECRET_PASS ""
#define SECRET_CH_ID 2285250
#define SECRET_WRITE_APIKEY "3JY6L1E3XOWZRMRE"
WiFiClient client;

unsigned long myChannelNumber = SECRET_CH_ID;
const char * myWriteAPIKEY = SECRET_WRITE_APIKEY;

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for SSD1306 display connected using I2C
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

int piezoPin = 26;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
   pinMode(27, INPUT_PULLUP);
   Serial.begin(115200); 
   Serial.println("hello buzz!");
   pinMode(piezoPin, OUTPUT);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  // Show initial display buffer contents on the screen --
  // the library initializes this with an Adafruit splash screen.
  display.display();
  delay(2000); // Pause for 2 seconds

  // Clear the buffer
  display.clearDisplay();


}

void loop() {
  Serial.println("Hello, ESP32!");

int a=digitalRead(27);
  Serial.println(a);
  if(a==HIGH)
  {

    Serial.println("motion detected");

  
  digitalWrite(piezoPin, HIGH);
  delay(5000);
  digitalWrite(piezoPin, LOW);
  }

  if(a==LOW)
   {
    Serial.println("motion not detected");
   }

   // Connect or reconnect to WiFi
  if(WiFi.status() != WL_CONNECTED){
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(SECRET_SSID);
    while(WiFi.status() != WL_CONNECTED){
      WiFi.begin(ssid, pass);  // Connect to WPA/WPA2 network. Change this line if using open or WEP network
      Serial.print(".");
      delay(5000);     
    } 
    Serial.println("\nConnected.");



// 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);

  // Calculating the distance
  distanceCm = duration * 0.034 / 2;

  //Convert to inches
  distanceInch = distanceCm * CM_TO_INCH;
  // Prints the distance on the Serial Monitor
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);
Serial.print("Distance (inch): ");
  Serial.println(distanceInch);

 display.clearDisplay();

  display.setTextSize(2);             // Normal 1:1 pixel scale
  display.setTextColor(WHITE);        // Draw white text
  display.setCursor(0,0);             // Start at top-left corner
  display.println(F("Distance:"));
  display.print(distanceCm);
  display.println(F("cm"));
  display.print(distanceInch);
  display.println(F("inch"));

  display.display();
  delay(2000);


  tone(piezoPin, 1000, 500);

  ThingSpeak.setField(1,distanceCm);
  ThingSpeak.setField(2,distanceInch);
  ThingSpeak.setField(3, pirStatus);

  
  // write to the ThingSpeak channel
  int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKEY);
  if(x == 200){
    Serial.println("Channel update successful.");
  }
  else{
    Serial.println("Problem updating channel. HTTP error code " + String(x));
  
}
delay (20000);
}