OTA.h

#include <ESPmDNS.h>

#include <WiFiUdp.h>
#include <ArduinoOTA.h>

// listener for skect upload invitation from arduino ide
void ota_handle( void * parameter ) {
  for (;;) {
    ArduinoOTA.handle();
    vTaskDelay(3500 / portTICK_PERIOD_MS);
  }
}

// prototype
void WiFiEvent(WiFiEvent_t event);

void setupOTA(const char* nameprefix) //, const char* ssid, const char* password) 
{
  // Configure the hostname
  uint16_t maxlen = strlen(nameprefix) + 7;
  char *fullhostname = new char[maxlen];
  uint8_t mac[6];

  WiFi.macAddress(mac);
  snprintf(fullhostname, maxlen, "%s-%02x%02x%02x", nameprefix, mac[3], mac[4], mac[5]);
  ArduinoOTA.setHostname(fullhostname);
  delete[] fullhostname;

  Serial.println("OTA Hostname set...");

  WiFi.setHostname(nameprefix);

  // Examples of different ways to register wifi events
  WiFi.onEvent(WiFiEvent);

  Serial.println("setupOTA - connected");

  ArduinoOTA.onStart([]() {
  //NOTE: make .detach() here for all functions called by Ticker.h library - not to interrupt transfer process in any way.
    String type;
    if (ArduinoOTA.getCommand() == U_FLASH)
      type = "sketch";
    else // U_SPIFFS
      type = "filesystem";

    // NOTE: if updating SPIFFS this would be the place to unmount SPIFFS using SPIFFS.end()
    Serial.println("Start updating " + type);
  });
  
  ArduinoOTA.onEnd([]() {
    Serial.println("\nEnd");
  });
  
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
  });
  
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    if (error == OTA_AUTH_ERROR) Serial.println("\nAuth Failed");
    else if (error == OTA_BEGIN_ERROR) Serial.println("\nBegin Failed");
    else if (error == OTA_CONNECT_ERROR) Serial.println("\nConnect Failed");
    else if (error == OTA_RECEIVE_ERROR) Serial.println("\nReceive Failed");
    else if (error == OTA_END_ERROR) Serial.println("\nEnd Failed");
  });

  Serial.println("setupOTA - about to begin");
  ArduinoOTA.begin();
  Serial.println("OTA Initialized");

  xTaskCreate(
    ota_handle,          /* Task function. */
    "OTA_HANDLE",        /* String with name of task. */
    10000,            /* Stack size in bytes. */
    NULL,             /* Parameter passed as input of the task */
    1,                /* Priority of the task. */
    NULL);            /* Task handle. */
    Serial.println("OTA task created");

}

void WiFiEvent(WiFiEvent_t event) {
  Serial.printf("[WiFi-event] event: %d\n", event);

  switch (event) {
    case SYSTEM_EVENT_WIFI_READY: 
      Serial.println("WiFi interface ready");
      break;
    case SYSTEM_EVENT_SCAN_DONE:
      Serial.println("Completed scan for access points");
      break;
    case SYSTEM_EVENT_STA_START:
      Serial.println("WiFi client started");
      break;
    case SYSTEM_EVENT_STA_STOP:
      Serial.println("WiFi clients stopped");
      break;
    case SYSTEM_EVENT_STA_CONNECTED:
      Serial.println("Connected to access point");
      break;
    case SYSTEM_EVENT_STA_DISCONNECTED:
      Serial.println("Disconnected from WiFi access point");
//      WiFi.begin(copy_ssid, copy_password);
//      WiFi.begin();
      break;
    case SYSTEM_EVENT_STA_AUTHMODE_CHANGE:
      Serial.println("Authentication mode of access point has changed");
      break;
    case SYSTEM_EVENT_STA_GOT_IP:
      Serial.print("Obtained IP address: ");
      Serial.println(WiFi.localIP());
      break;
    case SYSTEM_EVENT_STA_LOST_IP:
      Serial.println("Lost IP address and IP address is reset to 0");
      break;
    case SYSTEM_EVENT_STA_WPS_ER_SUCCESS:
      Serial.println("WiFi Protected Setup (WPS): succeeded in enrollee mode");
      break;
    case SYSTEM_EVENT_STA_WPS_ER_FAILED:
      Serial.println("WiFi Protected Setup (WPS): failed in enrollee mode");
      break;
    case SYSTEM_EVENT_STA_WPS_ER_TIMEOUT:
      Serial.println("WiFi Protected Setup (WPS): timeout in enrollee mode");
      break;
    case SYSTEM_EVENT_STA_WPS_ER_PIN:
      Serial.println("WiFi Protected Setup (WPS): pin code in enrollee mode");
      break;
    case SYSTEM_EVENT_AP_START:
      Serial.println("WiFi access point started");
      break;
    case SYSTEM_EVENT_AP_STOP:
      Serial.println("WiFi access point  stopped");
      break;
    case SYSTEM_EVENT_AP_STACONNECTED:
      Serial.println("Client connected");
      break;
    case SYSTEM_EVENT_AP_STADISCONNECTED:
      Serial.println("Client disconnected");
      break;
    case SYSTEM_EVENT_AP_STAIPASSIGNED:
      Serial.println("Assigned IP address to client");
      break;
    case SYSTEM_EVENT_AP_PROBEREQRECVED:
      Serial.println("Received probe request");
      break;
    case SYSTEM_EVENT_GOT_IP6:
      Serial.println("IPv6 is preferred");
      break;
    case SYSTEM_EVENT_ETH_START:
      Serial.println("Ethernet started");
      break;
    case SYSTEM_EVENT_ETH_STOP:
      Serial.println("Ethernet stopped");
      break;
    case SYSTEM_EVENT_ETH_CONNECTED:
      Serial.println("Ethernet connected");
      break;
    case SYSTEM_EVENT_ETH_DISCONNECTED:
      Serial.println("Ethernet disconnected");
      break;
    case SYSTEM_EVENT_ETH_GOT_IP:
      Serial.println("Obtained IP address");
      break;
    default: break;
}}