/*********************************************************************
 This is an example for our nRF52 based Bluefruit LE modules

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 All text above, and the splash screen below must be included in
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*********************************************************************/

/* This sketches demontrates the Bluefruit.Advertising API(). When powered up,
 * the Bluefruit module will start advertising for ADV_TIMEOUT seconds (by
 * default 30 seconds in fast mode, the remaining time slow mode) and then
 * stop advertising completely. The module will start advertising again if
 * PIN_ADV is grounded.
 */
#include <bluefruit.h>

#define PIN_ADV       A0
#define ADV_TIMEOUT   60 // seconds

void setup() 
{
  // configure PIN_ADV as input with a pullup (pin is active low)
  pinMode(PIN_ADV, INPUT_PULLUP);
  
  Serial.begin(115200);
  while ( !Serial ) delay(10);   // for nrf52840 with native usb

  Serial.println("Bluefruit52 Advanced Advertising Example");
  Serial.println("----------------------------------------\n");

  Bluefruit.begin();
  // Set max power. Accepted values are: -40, -30, -20, -16, -12, -8, -4, 0, 4
  Bluefruit.setTxPower(4);
  Bluefruit.setName("Bluefruit52");

  // Set up and start advertising
  startAdv();

  Serial.println("Advertising is started"); 
}

void startAdv(void)
{   
  // Advertising packet
  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
  Bluefruit.Advertising.addTxPower();
  Bluefruit.Advertising.addName();

  /* Start Advertising
   * - Enable auto advertising if disconnected
   * - Interval:  fast mode = 20 ms, slow mode = 152.5 ms
   * - Timeout for fast mode is 30 seconds
   * - Start(timeout) with timeout = 0 will advertise forever (until connected)
   * 
   * For recommended advertising interval
   * https://developer.apple.com/library/content/qa/qa1931/_index.html
   */
  Bluefruit.Advertising.setStopCallback(adv_stop_callback);
  Bluefruit.Advertising.restartOnDisconnect(true);
  Bluefruit.Advertising.setInterval(32, 244);    // in units of 0.625 ms
  Bluefruit.Advertising.setFastTimeout(30);      // number of seconds in fast mode
  Bluefruit.Advertising.start(ADV_TIMEOUT);      // Stop advertising entirely after ADV_TIMEOUT seconds 
}

void loop() 
{
  // Only check pin when advertising has already stopped
  if ( !Bluefruit.Advertising.isRunning() )
  {
    // Check if Pin is grounded
    if ( digitalRead(PIN_ADV) == 0 )
    {
      Bluefruit.Advertising.start(ADV_TIMEOUT);
      Serial.println("Advertising is started");
    }
  }
}

/**
 * Callback invoked when advertising is stopped by timeout
 */
void adv_stop_callback(void)
{
  Serial.println("Advertising time passed, advertising will now stop.");
}