#include <WiFi.h>
#include "ThingSpeak.h"

// Ultrasonic Sensor Pins
#define TRIG_PIN 12
#define ECHO_PIN 14
#define SOUND_VELOCITY 0.034 // Speed of sound in cm/µs

// WiFi Credentials
const char* WIFI_NAME = "Wokwi-GUEST";
const char* WIFI_PASSWORD = "";

// ThingSpeak Details
const int myChannelNumber =3019352;
const char* myApiKey = "RE2D294Z8066T4MV";
WiFiClient client;

long duration;
float distanceCm;

void setup() {
  // Initialize Serial Monitor
  Serial.begin(115200);

  // Configure TRIG and ECHO Pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // Connect to WiFi
  Serial.print("Connecting to WiFi");
  WiFi.begin(WIFI_NAME, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
  Serial.println("Local IP: " + String(WiFi.localIP()));

  // Initialize ThingSpeak
  ThingSpeak.begin(client);
}

void loop() {
  // Clear the TRIG pin
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  // Send a 10-microsecond pulse to TRIG pin
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Measure the duration of the ECHO pin
  duration = pulseIn(ECHO_PIN, HIGH);

  // Calculate the distance in centimeters
  distanceCm = (duration * SOUND_VELOCITY) / 2;

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

  // Send data to ThingSpeak
  ThingSpeak.setField(1, distanceCm);
  int response = ThingSpeak.writeFields(myChannelNumber, myApiKey);

  // Check if data push was successful
  if (response == 200) {
    Serial.println("Data sent to ThingSpeak successfully!");
  } else {
    Serial.println("Error sending data to ThingSpeak. Response: " + String(response));
  }

  // Wait for 15 seconds (ThingSpeak limit)
  delay(15000);
}