const int trigPin = 5;
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;
#include <WiFi.h>
#include <ThingSpeak.h>
char ssid[] = "Wokwi-GUEST";
char pass[] = "";
WiFiClient client;
unsigned long myChannelNumber =  2287052;
const char * myWriteAPIKey = "FHVE86F78WNHXCX5";
int a , statusCode;


void setup() {
  Serial.begin(115200); // Starts the serial communication
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT);
  Serial.begin(115200);
  WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client); // Sets the echoPin as an Input
}

void loop() {
  // Clears the trigPin
  
  
  delay(1000);
  if(WiFi.status() != WL_CONNECTED)
{
Serial.print("Attempting to connect");
while(WiFi.status() != WL_CONNECTED)
{
WiFi.begin(ssid, pass); 
Serial.print(".");
delay(5000);
}
Serial.println("\nConnected.");
}
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 = duration * SOUND_SPEED/2;
  a=distanceCm;
  
  
  
  // Prints the distance in the Serial Monitor
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);


statusCode = ThingSpeak.writeField(myChannelNumber, 1, a,
myWriteAPIKey);
if(statusCode == 200) { //successful writing code
Serial.println("Channel update successful.");
}
else {

Serial.println("Problem Writing data. HTTP error code :" +
String(statusCode));
}
delay(15000); // data to be uploaded every 15secs
}