#include "esp_timer.h"

const int ledPin = 2;
bool ledState = false;
esp_timer_handle_t timerHandle;

void IRAM_ATTR onTimer(void* arg) {
  ledState = !ledState;  
  digitalWrite(ledPin, ledState);
}

void setup() {
  pinMode(ledPin, OUTPUT);
  
  esp_timer_create_args_t timerArgs = {
    .callback = &onTimer,  // Assign the corrected function
    .arg = NULL,           // No arguments needed
    .dispatch_method = ESP_TIMER_TASK,  // Run in a dedicated task
    .name = "LED Timer"
  };
  
  esp_timer_create(&timerArgs, &timerHandle);
  esp_timer_start_periodic(timerHandle, 500000);  // 500,000 µs = 500ms
}

void loop() {
  // Main loop does nothing; interrupt handles LED blinking
}