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

char ssid[] = "Wokwi-GUEST";
char pwd[] = "";
WiFiClient client;

const int trigPin = 27;
const int echoPin = 26;
const int redlight_Pin = 2;
const float GAMMA = 0.7;
const float RL10 = 50;
int a =0;
int analogValue = 35;
float voltage = analogValue / 1024. * 5;
float resistance = 2000 * voltage / (1 - voltage / 5);
float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));


unsigned long channelId = 2274627;
const char w_api_key[] = "HFPCELT5PIHCRHFB";
int status_code;

int get_distance() {
  digitalWrite(trigPin, LOW);
  delay(200);
  digitalWrite(trigPin, HIGH);
  delay(200);
  digitalWrite(trigPin, LOW);
  int duration = pulseIn(echoPin, HIGH);
  return(duration * (0.034 / 2));
}

void setup() {
  Serial.begin(115200);
  pinMode(redlight_Pin, OUTPUT);
  
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client);
  delay(2000);
}

void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("Establishing WiFi Connection");
  
    while (WiFi.status() != WL_CONNECTED) {
      WiFi.begin(ssid, pwd);
      delay(5000);
    }

    Serial.println("Established WiFi Connection");
  }

  Serial.println("Distance: " + String(get_distance()));
  ThingSpeak.setField(1, get_distance());
  delay(1000);

  if (get_distance() < 200)
  {
    digitalWrite(redlight_Pin, HIGH);
    
    Serial.println(a = 1);
    //ThingSpeak.SetField(1,distance);
    //Thingspeak.SetField(2,a);
  }
  else{
    digitalWrite(redlight_Pin, LOW);
    
    Serial.println(a = 0);
   
  }
  

  status_code = ThingSpeak.writeFields(channelId, w_api_key);
  if (status_code != 200)
    Serial.println("HTTP Error: Returned with status code: " + String(status_code));
  else
    Serial.println("HTTP INFO: Channel updated on ThingSpeak successfully");
  delay(15000);
}