MQ-2 ต่อกับESP32 ส่งข้อความเข้าไลน์ แต่วัดค่าได้ 4095 ตลอด

#include <WiFi.h>
#include <WiFiClientSecure.h>

void Line_Notify(String message) ;

#define WIFI_SSID "XXX"
#define WIFI_PASSWORD "XXX"
#define LINE_TOKEN "XXXXX"

int DONOKLed = 13;
int OKLed = 12;
int smokeA4 = 4;
// Your threshold value
int sensorThres = 3000;

void setup() {
  pinMode(DONOKLed, OUTPUT);
  pinMode(OKLed, OUTPUT);
  pinMode(smokeA4, INPUT);
  Serial.begin(9600);
  
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("connecting");

  while (WiFi.status() != WL_CONNECTED) {
    Serial.println(".");
    delay(500);
  }
  Serial.println();
  Serial.print("connected: ");
  Serial.println(WiFi.localIP());
  }

void loop() 
{
 int analogSensor = analogRead(smokeA4);
  Serial.print("Pin 4: ");
  Serial.println(analogSensor);
  // Checks if it has reached the threshold value
  if (analogSensor > sensorThres)
  {
    digitalWrite(DONOKLed, HIGH);
    digitalWrite(OKLed, LOW);
    Line_Notify("Beware of fire risks");
    delay(7000);
  }
  else
  {
    digitalWrite(DONOKLed, LOW);
    digitalWrite(OKLed, HIGH);
  }
    Serial.print(analogSensor);
  delay(100);
}

void Line_Notify(String message) {
  WiFiClientSecure client;
  if (!client.connect("notify-api.line.me", 443)) {
    Serial.println("connection failed");  
    return;
  }
  
  
  String req = "";
  req += "POST /api/notify HTTP/1.1\r\n";
  req += "Host: notify-api.line.me\r\n";
  req += "Authorization: Bearer " + String(LINE_TOKEN) + "\r\n";
  req += "Cache-Control: no-cache\r\n";
  req += "User-Agent: ESP8266\r\n";
  req += "Connection: close\r\n";
  req += "Content-Type: application/x-www-form-urlencoded\r\n";
  req += "Content-Length: " + String(String("message=" + message).length()) + "\r\n";
  req += "\r\n";
  req += "message=" + message;
  // Serial.println(req);
  client.print(req);
    
  delay(20);

  // Serial.println("-------------");
  while(client.connected()) {
    String line = client.readStringUntil('\n');
    if (line == "\r") {
      break;
    }
    //Serial.println(line);
  }
  // Serial.println("-------------");
}