#include <WiFi.h>
#include "ThingSpeak.h"
#define echoPin 12 // attach pin D12 ESP to pin Echo of HC-SR04
#define trigPin 13 //attach pin D13 ESP to pin Trig of HC-SR04

// Channel Details:
unsigned long myChannelNumber = 1871183;
const char * myWriteAPIKey = "PA2O05AGTTLAQH4N";
char ssid[] = "Wokwi-GUEST";   // your network SSID (name)
char pass[] = "";   // your network password
int keyIndex = 0;            // your network key Index number (needed only for WEP)
WiFiClient  client;
String myStatus = "";

// defines variables
long duration;
int distance;
int percentfull; 

void setup() {
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
  Serial.begin(9600); // // Serial Communication is starting with 9600 of baudrate speed
  Serial.println("Ultrasonic Sensor HC-SR04 Test"); // print some text in Serial Monitor
  Serial.println("with ESP 32");
  //WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client);  // Initialize ThingSpeak
}

void loop() {
  // Connect or reconnect to WiFi
  if (WiFi.status() != WL_CONNECTED) {
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(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.");
  }
  delay(2500);

  // Clears the trigPin condition
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
  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
  distance = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
  // Displays the distance on the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

percentfull = distance/4;
Serial.print("Percentage Full : " );
Serial.println(percentfull);
  ThingSpeak.setField(2, String(percentfull));
  // set the status
  ThingSpeak.setStatus(myStatus);
  // 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); // Wait 20 seconds to update the channel again

}