text: /* 
   * The MIT License (MIT)
   *
   * Copyright (c) 2019 Ha Thach (tinyusb.org)
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   *
   */
  
  #include <stdlib.h>
  #include <stdio.h>
  #include <string.h>
  
  #include "bsp/board.h"
  #include "tusb.h"
  
  //--------------------------------------------------------------------+
  // MACRO CONSTANT TYPEDEF PROTYPES
  //--------------------------------------------------------------------+
  
  /* Blink pattern
   * - 250 ms  : device not mounted
   * - 1000 ms : device mounted
   * - 2500 ms : device is suspended
   */
  enum  {
    BLINK_NOT_MOUNTED = 250,
    BLINK_MOUNTED = 1000,
    BLINK_SUSPENDED = 2500,
  };
  
  static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
  
  void led_blinking_task(void);
  
  /*------------- MAIN -------------*/
  int main(void)
  {
    board_init();
  
    tusb_init();
  
    while (1)
    {
      // tinyusb device task
      tud_task();
  
      led_blinking_task();
    }
  
    return 0;
  }
  
  //--------------------------------------------------------------------+
  // Device callbacks
  //--------------------------------------------------------------------+
  
  // Invoked when device is mounted
  void tud_mount_cb(void)
  {
    blink_interval_ms = BLINK_MOUNTED;
  }
  
  // Invoked when device is unmounted
  void tud_umount_cb(void)
  {
    blink_interval_ms = BLINK_NOT_MOUNTED;
  }
  
  // Invoked when usb bus is suspended
  // remote_wakeup_en : if host allow us  to perform remote wakeup
  // Within 7ms, device must draw an average of current less than 2.5 mA from bus
  void tud_suspend_cb(bool remote_wakeup_en)
  {
    (void) remote_wakeup_en;
    blink_interval_ms = BLINK_SUSPENDED;
  }
  
  // Invoked when usb bus is resumed
  void tud_resume_cb(void)
  {
    blink_interval_ms = BLINK_MOUNTED;
  }
  
  //--------------------------------------------------------------------+
  // BLINKING TASK
  //--------------------------------------------------------------------+
  void led_blinking_task(void)
  {
    static uint32_t start_ms = 0;
    static bool led_state = false;
  
    // Blink every interval ms
    if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
    start_ms += blink_interval_ms;
  
    board_led_write(led_state);
    led_state = 1 - led_state; // toggle
  }
  