ESP8266/ESP32 Upload program over the air (OTA)

BasicOTA.h

//#include <WiFi.h>   // ESP32
//#include <ESPmDNS.h>    // ESP32
#include <ESP8266WiFi.h>  // ESP8266
#include <ESP8266mDNS.h>  // ESP8266
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

void setupOTA(char ssid[], char password[]) {
  Serial.begin(115200);
  Serial.println("Booting");
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    Serial.println("Connection Failed! Rebooting...");
    delay(5000);
    ESP.restart();
  }

  // Port defaults to 3232
  // ArduinoOTA.setPort(3232);

  // Hostname defaults to esp3232-[MAC]
  // ArduinoOTA.setHostname("myesp32");

  // No authentication by default
  // ArduinoOTA.setPassword("admin");

  // Password can be set with it's md5 value as well
  // MD5(admin) = 21232f297a57a5a743894a0e4a801fc3
  // ArduinoOTA.setPasswordHash("21232f297a57a5a743894a0e4a801fc3");

  ArduinoOTA
    .onStart([]() {
      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("Auth Failed");
      else if (error == OTA_BEGIN_ERROR) Serial.println("Begin Failed");
      else if (error == OTA_CONNECT_ERROR) Serial.println("Connect Failed");
      else if (error == OTA_RECEIVE_ERROR) Serial.println("Receive Failed");
      else if (error == OTA_END_ERROR) Serial.println("End Failed");
    });

  ArduinoOTA.begin();

  Serial.println("Ready");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void handleOTA() {
  ArduinoOTA.handle();
}

Blink.ino

#include "BasicOTA.h"

int LED_BUILTIN = 2;

char* ssid1 = "..........";
char* password2 = "..........";

// the setup function runs once when you press reset or power the board
void setup() {
  setupOTA(ssid1, password2);
  
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
  
}

// the loop function runs over and over again forever
void loop() {
  handleOTA();
  
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(100);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(100);                       // wait for a second
}