/*
  Wokwi | questions
  I need help asap!!

  jasper - Monday, June 1, 2026 9:18 AM
  https://wokwi.com/projects/465631428885803009
  im doing a project on automatic food dispenser for stray animals,
  im only focusing on using ultrasonic sensor to give detect the
  remaning food level in the container and using a servo motor to
  dispense food out...im controlling all these components using
  Blynk app....my hardware works fine but the wokwi coding shows
  error, pls help to create a proper coding for my simulation to
  work, thank you!
*/

#define BLYNK_PRINT Serial
/* Fill in information from Blynk Device Info here */
#define BLYNK_TEMPLATE_ID "TMPL6i-wnkZx1"
#define BLYNK_TEMPLATE_NAME "food dispenser"
#define BLYNK_AUTH_TOKEN "fMLmk4Jy6WlQZgL_IRj-GPU3b5MWFECR"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <ESP32Servo.h>

// pin constants
const int TRIG_PIN = 23;
const int ECHO_PIN = 22;
const int SERVO_PIN = 18;

// notification flag
bool notified = false;

Servo servo1;

// function to measure distance
int getDistance() {
  // send trigger pulse
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  // read pulse duration
  long duration = pulseIn(ECHO_PIN, HIGH);
  // calculate distance
  long distance = duration * 0.0343 / 2;
  return (int)distance + 0.5;
}

// Slider widget for servo
BLYNK_WRITE(V2) {
  int pos1 = param.asInt(); // Get value from slider
  servo1.write(pos1); // Set servo 1 position
  Blynk.virtualWrite(V3, pos1);
}

void setup() {
  Serial.begin(9600);
  Blynk.begin(BLYNK_AUTH_TOKEN, "Wokwi-GUEST", "");
  pinMode(ECHO_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  servo1.attach(SERVO_PIN);
}

void loop() {
  Blynk.run();

  int distance = getDistance();
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Send to Blynk display
  Blynk.virtualWrite(V1, distance);

  // FOOD LOW CONDITION
  if (distance > 10 && !notified) { // adjust value
    Serial.println("Food is LOW!");
    Blynk.logEvent("food_low", "Food container is empty!");
    notified = true;
  }

  // Reset notification when refilled
  if (distance < 5) {
    notified = false;
  }
  delay(1000);
}