#include <Arduino_ConnectionHandler.h>
/* ... */
#if defined(BOARD_HAS_WIFI)
WiFiConnectionHandler conMan("SECRET_SSID", "SECRET_PASS");
#elif defined(BOARD_HAS_GSM)
GSMConnectionHandler conMan("SECRET_PIN", "SECRET_APN", "SECRET_GSM_LOGIN", "SECRET_GSM_PASS");
#elif defined(BOARD_HAS_NB)
NBConnectionHandler conMan("SECRET_PIN", "SECRET_APN", "SECRET_GSM_LOGIN", "SECRET_GSM_PASS");
#elif defined(BOARD_HAS_LORA)
LoRaConnectionHandler conMan("SECRET_APP_EUI", "SECRET_APP_KEY");
#endif
/* ... */
void setup() {
  Serial.begin(9600);
  while(!Serial) { }

  setDebugMessageLevel(DBG_INFO);

  conMan.addCallback(NetworkConnectionEvent::CONNECTED, onNetworkConnect);
  conMan.addCallback(NetworkConnectionEvent::DISCONNECTED, onNetworkDisconnect);
  conMan.addCallback(NetworkConnectionEvent::ERROR, onNetworkError);
}

void loop() {
  /* The following code keeps on running connection workflows on our
   * ConnectionHandler object, hence allowing reconnection in case of failure
   * and notification of connect/disconnect event if enabled (see
   * addConnectCallback/addDisconnectCallback) NOTE: any use of delay() within
   * the loop or methods called from it will delay the execution of .check(),
   * which might not guarantee the correct functioning of the ConnectionHandler
   * object.
   */
  conMan.check();
}
/* ... */
void onNetworkConnect() {
  Serial.println(">>>> CONNECTED to network");
}

void onNetworkDisconnect() {
  Serial.println(">>>> DISCONNECTED from network");
}

void onNetworkError() {
  Serial.println(">>>> ERROR");
}