#include <WiFi.h>

#include <ThingSpeak.h>



// Pin Definitions

#define TRIG_PIN 23    

#define ECHO_PIN 22    



// WiFi Credentials (Wokwi Simulator)

const char* ssid = "Wokwi-GUEST";

const char* password = "";



// ThingSpeak Configuration (Updated with User Keys)

unsigned long myChannelNumber = 3237942; 

const char * myWriteAPIKey = "CH6MJOUTWEUCBDTK"; 



WiFiClient client;



void setup() {

  Serial.begin(115200);

  pinMode(TRIG_PIN, OUTPUT);

  pinMode(ECHO_PIN, INPUT);



  // Connect to WiFi

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {

    delay(500);

    Serial.print(".");

  }

  Serial.println("\nWiFi Connected!");

  

  ThingSpeak.begin(client);

}



void loop() {

  // Distance Measurement

  digitalWrite(TRIG_PIN, LOW);

  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);

  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);



  long duration = pulseIn(ECHO_PIN, HIGH);

  float distance = duration * 0.017;



  // Upload to ThingSpeak Field 1

  ThingSpeak.setField(1, distance);

  

  int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);

  

  if(x == 200){

    Serial.println("Cloud Update Successful: " + String(distance) + " cm");

  } else {

    Serial.println("HTTP Error Code: " + String(x));

  }



  // ThingSpeak update limit is 15 seconds

  delay(15000); 

}