// ESP32 - 1 kHz LED Blink via Hardware Timer Interrupt
// Compatible with ESP32 Arduino Core v3.x (new timer API)

#define LED_PIN 0  // Built-in LED on most ESP32 dev boards

volatile bool ledState = false;

hw_timer_t* timer = NULL;

// ISR - fires at 2 kHz, toggles LED → full ON/OFF cycle = 1 kHz
void IRAM_ATTR onTimer() {
  ledState = !ledState;
  digitalWrite(LED_PIN, ledState);
}

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);

  // New API (Core v3.x): timerBegin(frequency_hz)
  // 2000 Hz ISR → LED toggles 2000x/sec → blink cycle = 1 kHz
  timer = timerBegin(2000);

  // Attach ISR
  timerAttachInterrupt(timer, &onTimer);

  // Alarm every 1 tick at 2000 Hz = every 500 µs
  timerAlarm(timer, 1, true, 0);

  Serial.println("1 kHz LED blink started (Core v3.x API).");
}

void loop() {
  // Main loop is free — all work done in ISR
  delay(1000);
  Serial.println("Running... LED blinking at 1 kHz.");
}

// urlencoded
// https://randomnerdtutorials.com/esp32-http-get-post-arduino/#http-post
// https://docs.arduino.cc/libraries/httpclient/
// receiving JSON POST https://www.geeksforgeeks.org/how-to-receive-json-post-with-php/

#include <ArduinoJson.h>
#include <HTTPClient.h>
#include <WiFiMulti.h>

const char *AP_SSID = "AP Name";
const char *AP_PWD = "AP password";

void setup() {
  Serial.begin(115200);

  WiFi.begin(AP_SSID, AP_PWD);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");
  Serial.print("ESP32 Web Server's IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  postDataToServer();
  delay(10000);  // delay 10 seconds
}
int counter = 0;
void postDataToServer() {
  Serial.println("Posting POST data to server...");
  // Block until we are able to connect to the WiFi access point
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin("http://192.168.0.139/post.php");
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");
    
    // parameter POST dummy, kecuali counter yang diupdate teratur

    String httpRequestData = "api_key=tPmAT5Ab3j7F9&sensor=BME280&value1=24.25&value2=49.54&value3=1005.14&counter=" + String(counter);
    int httpResponseCode = http.POST(httpRequestData);
    if (httpResponseCode > 0) {
      String response = http.getString();
      Serial.println(httpResponseCode);
      Serial.println(response);  // cek untuk debugging

    } else {
      Serial.print("error code");
      Serial.print(httpResponseCode);
      // error codes from https://github.com/amcewen/HttpClient/blob/master/HttpClient.h
      // static const int HTTP_ERROR_CONNECTION_FAILED =-1;
      // static const int HTTP_ERROR_API =-2;
      // static const int HTTP_ERROR_TIMED_OUT =-3;
      // static const int HTTP_ERROR_INVALID_RESPONSE =-4;
    }
  }
  counter++;
}

// contoh program membaca digital input menggunakan digitalRead()
#define INPUT_PIN 33

void setup() {
  pinMode(INPUT_PIN, INPUT_PULLUP);
  Serial.begin(115200);
  Serial.println("\nContoh program membaca digital input menggunakan digitalRead()");
  Serial.println(__FILE__");
}

void loop() {
  int input_value;
  input_value = digitalRead(INPUT_PIN);
  Serial.println(input_value);
  delay(1000);
}