Fix unreachable net services V2

Attention: This usermod compiles only for ESP8266

This usermod-v2 modification performs a ping request to the local IP address every 60 seconds. By this procedure the net services of WLED remains accessible in some problematic WLAN environments.

The modification works with static or DHCP IP address configuration.

Story:

Unfortunately, with all ESP projects where a web server or other network services are running, I have the problem that after some time the web server is no longer accessible. Now I found out that the connection is at least reestablished when a ping request is executed by the device.

With this modification, in the worst case, the network functions are not available for 60 seconds until the next ping request.

Webinterface

The number of pings and reconnects is displayed on the info page in the web interface. The ping delay can be changed. Changes persist after a reboot.

JSON API

The usermod supports the following state changes:

JSON key	Value range	Description
PingDelayMs	5000 to 18000000	Deactivdate/activate the sensor

Changes also persist after a reboot.

Installation

1. Copy the file usermod_Fix_unreachable_netservices.h to the wled00 directory.
2. Register the usermod by adding #include "usermod_Fix_unreachable_netservices.h" in the top and registerUsermod(new FixUnreachableNetServices()); in the bottom of usermods_list.cpp.

Example usermods_list.cpp:

#include "wled.h"
/*
 * Register your v2 usermods here!
 *   (for v1 usermods using just usermod.cpp, you can ignore this file)
 */

/*
 * Add/uncomment your usermod filename here (and once more below)
 * || || ||
 * \/ \/ \/
 */
//#include "usermod_v2_example.h"
//#include "usermod_temperature.h"
//#include "usermod_v2_empty.h"
#include  "usermod_Fix_unreachable_netservices.h"

void registerUsermods()
{
  /*
   * Add your usermod class name here
   * || || ||
   * \/ \/ \/
   */
  //usermods.add(new MyExampleUsermod());
  //usermods.add(new UsermodTemperature());
  //usermods.add(new UsermodRenameMe());
  usermods.add(new FixUnreachableNetServices());

}

Hopefully I can help someone with that - @gegu