ESP8266 WiFi range extender Arduino

/*
   Copyright (c) 2015, Majenko Technologies
   All rights reserved.

   Redistribution and use in source and binary forms, with or without modification,
   are permitted provided that the following conditions are met:

 * * Redistributions of source code must retain the above copyright notice, this
     list of conditions and the following disclaimer.

 * * Redistributions in binary form must reproduce the above copyright notice, this
     list of conditions and the following disclaimer in the documentation and/or
     other materials provided with the distribution.

 * * Neither the name of Majenko Technologies nor the names of its
     contributors may be used to endorse or promote products derived from
     this software without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
   ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/* 
 *  Author: Pius Onyema Ndukwu
 *  License: MIT License
 *  GitHub: https://github.com/Pius171/esp8266-wifi-extender
 */
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESPAsyncTCP.h>
#include <ESPAsyncWebServer.h>
#include <ArduinoJson.h>
#include <FS.h>
#include <LittleFS.h>

AsyncWebServer server(80);
DynamicJsonDocument Config(2048);


// variables
bool RepeaterIsWorking= true;
int ledState = LOW; 
unsigned long previousMillis = 0;
long delay_time=0; // interval between blinks
// blink every 200ms if connected to router
// blink every 1sec if web server is active
// led is off is there is an error with the repeater
//led is on when trying to connect to router.


/* Set these to your desired credentials. */

#if LWIP_FEATURES && !LWIP_IPV6

#define HAVE_NETDUMP 0


#include <ESP8266WiFi.h>
#include <lwip/napt.h>
#include <lwip/dns.h>
#include <LwipDhcpServer.h>

#define NAPT 1000
#define NAPT_PORT 10

#if HAVE_NETDUMP

#include <NetDump.h>


void dump(int netif_idx, const char* data, size_t len, int out, int success) {
  (void)success;
  Serial.print(out ? F("out ") : F(" in "));
  Serial.printf("%d ", netif_idx);

  // optional filter example: if (netDump_is_ARP(data))
  {
    netDump(Serial, data, len);
    //netDumpHex(Serial, data, len);
  }
}
#endif


class wifi {

  public:

    JsonObject obj = Config.as<JsonObject>();

    // just added this so i can see the files in the file system
    void listDir(const char * dirname) {
      Serial.printf("Listing directory: %s\n", dirname);

      Dir root = LittleFS.openDir(dirname);

      while (root.next()) {
        File file = root.openFile("r");
        Serial.print("  FILE: ");
        Serial.print(root.fileName());
        Serial.print("  SIZE: ");
        Serial.print(file.size());
        file.close();

      }
    }

    void create_server() {

      server.on("/", HTTP_GET, [](AsyncWebServerRequest * request) {

        // scan for networks and get ssid
        String network_html = "";


        // link to code https://github.com/me-no-dev/ESPAsyncWebServer/issues/85#issuecomment-258603281
        // there is a problem with scanning whil using espasync that is why the code below is not just WiFi.scan()
        int n = WiFi.scanComplete();
        if (n == -2) {
          WiFi.scanNetworks(true);
        } else if (n) {
          for (int i = 0; i < n; ++i) {
            String router = WiFi.SSID(i);
            Serial.println(router);
            network_html += "<input type=\"radio\" id=\"#radiobuttonex\" name=\"ssid\" value=" + router + " required ><label for=\"html\">" + router + "</label><<br>";

          }
          WiFi.scanDelete();
          if (WiFi.scanComplete() == -2) {
            WiFi.scanNetworks(true);
          }
        }

        String html = "<!DOCTYPE html><html>";
        html+= "<head>";
        html+=" <link rel=\"stylesheet\" href=\"styles.css\">";
        html+= "</head>";
        html += "<body>";
        html+= "<div>";
        html += "<h1>Pius Electronics Extender Config page</h1>";
        html += "<button onclick=\"window.location.href='/';\">Scan </button>";
        html += "<p>networks found </p>";
        html += "<form action=\"/credentials\">";
        html += "<p>Please select a WiFi network:</p>" + network_html;
        html += "<input type=\"password\" id=\"pass\" name=\"pass\" value=\"\" required ><label for=\"pass\">password</label><br><br>";
        html += "<input type=\"text\" id=\"ap\" name=\"ap\" value=\"\" required ><label for=\"ap\">A.P name:</label><br>";
        html += "<input type=\"submit\" value=\"Submit\">";
        html += "</form></body></html>";
        html+= "</div>";

        request->send(200, "text/html", html);
      });

// css style from grepper
      server.on("/styles.css", HTTP_GET, [](AsyncWebServerRequest * request) {
        String style = "#radiobuttonex{\n"
"  border: 2px solid rgb(255,1,199);\n"
"  text-align: center;\n"
"  font-family: sans serif;\n"
"  width: 305px;\n"
"  background: rgb(50,50,100);\n"
"  border-radius: 40px;\n"
"}";
        
       request->send(200, "text/css", style);
        
        });

      // Send a GET request to <IP>/get?message=<message> 
      server.on("/credentials", HTTP_GET, [] (AsyncWebServerRequest * request) {
        String param = "ssid";

        if (request->hasParam(param)) {
          String ssid = request->getParam(param)->value();
          Config["ssid"] = ssid;
          Serial.println(ssid);
        } else {
          Serial.println("No " + param + " sent");
        }

        param = "pass";
        if (request->hasParam(param)) {
          String pass = request->getParam(param)->value();
          Config["pass"] = pass;
          Serial.println(pass);
        } else {
          Serial.println("No " + param + " sent");
        }

        param = "ap";
        if (request->hasParam(param)) {
          String ap = request->getParam(param)->value();
          Config["ap"] = ap;
          Serial.println(ap);
        } else {
          Serial.println("No " + param + " sent");
        }
        String output;
        serializeJson(Config, output);
        Serial.print(output);

        String path = "/config.json";

        Serial.printf("Writing file: %s\n", path);

        File file = LittleFS.open(path, "w");
        if (!file) {
          Serial.println("Failed to open file for writing");
          return "null";
        }
        if (file.print(output)) {
          Serial.println("File written");
        } else {
          Serial.println("Write failed");
        }
        file.close();

      });

    }



    String get_credentials(int a) {
      // a: 0=ssid, 1=pass; 2=ap name
      String path = "/config.json";
      String credentials = "";

      Serial.print("reading file ");
      Serial.println(path);

      File file = LittleFS.open(path, "r");
      if (!file) {
        Serial.println("Failed to open file for reading");
        Serial.println("this is probally first usage, so the file does not exist");
        return "null";
      }

      Serial.print("Read from file: ");
      while (file.available()) {
        credentials += file.readString();

      }
      Serial.println(credentials);
      deserializeJson(Config, credentials);
      file.close();
      String credential_array [3] = {Config["ssid"], Config["pass"], Config["ap"]};
      return credential_array[a];
    }

};



wifi my_wifi;


void setup() {
  delay(1000);
 pinMode(0,INPUT_PULLUP);
 pinMode(LED_BUILTIN,OUTPUT);
 digitalWrite(LED_BUILTIN,1); //active low
  Serial.begin(115200);

  Serial.println();

  if (!LittleFS.begin()) {
    Serial.println("LittleFS mount failed");
    return;
  }

  Serial.printf("\n\nNAPT Range extender\n");
  Serial.printf("Heap on start: %d\n", ESP.getFreeHeap());

#if HAVE_NETDUMP
  phy_capture = dump;
#endif

  // first, connect to STA so we can get a proper local DNS server


  String ssid = my_wifi.get_credentials(0); // if the file does not exist the function will always return null
  String pass = my_wifi.get_credentials(1);
  String ap= my_wifi.get_credentials(2);

  if (ssid == "null") { // if the file does not exist ssid will be null
start_webserver:
    IPAddress myIP = WiFi.softAPIP();
    Serial.print("AP IP address: ");
    Serial.println(myIP);
    WiFi.softAP("Pius_Electronics_extender0001");
    Serial.printf("AP: %s\n", WiFi.softAPIP().toString().c_str());
    my_wifi.create_server();
    server.begin();
    Serial.println("HTTP server started");
    delay_time=1000; // blink every sec if webserver is active
  }
  else {
    WiFi.mode(WIFI_STA);
    WiFi.begin(ssid, pass); // check function to understand
    int timeout_counter=0;
    while (WiFi.status() != WL_CONNECTED) {
      if(timeout_counter>=120){
        goto start_webserver; // if it fails to connect start_webserver
      }

      Serial.print('.');
      timeout_counter++;
      digitalWrite(LED_BUILTIN,0);// leave led on when trying to connect
      delay(500);
    }



    Serial.printf("\nSTA: %s (dns: %s / %s)\n",
                  WiFi.localIP().toString().c_str(),
                  WiFi.dnsIP(0).toString().c_str(),
                  WiFi.dnsIP(1).toString().c_str());

    // give DNS servers to AP side
    dhcpSoftAP.dhcps_set_dns(0, WiFi.dnsIP(0));
    dhcpSoftAP.dhcps_set_dns(1, WiFi.dnsIP(1));

    WiFi.softAPConfig(  // enable AP, with android-compatible google domain
      IPAddress(172, 217, 28, 254),
      IPAddress(172, 217, 28, 254),
      IPAddress(255, 255, 255, 0));
    WiFi.softAP(ap, pass);
    Serial.printf("AP: %s\n", WiFi.softAPIP().toString().c_str());

    Serial.printf("Heap before: %d\n", ESP.getFreeHeap());
    err_t ret = ip_napt_init(NAPT, NAPT_PORT);
    Serial.printf("ip_napt_init(%d,%d): ret=%d (OK=%d)\n", NAPT, NAPT_PORT, (int)ret, (int)ERR_OK);
    if (ret == ERR_OK) {
      ret = ip_napt_enable_no(SOFTAP_IF, 1);
      Serial.printf("ip_napt_enable_no(SOFTAP_IF): ret=%d (OK=%d)\n", (int)ret, (int)ERR_OK);
      if (ret == ERR_OK) {
        Serial.printf("Successfully NATed to WiFi Network '%s' with the same password", ssid.c_str());
      }
    }
    Serial.printf("Heap after napt init: %d\n", ESP.getFreeHeap());
    if (ret != ERR_OK) {
      Serial.printf("NAPT initialization failed\n");
    }
    delay_time=200; // blink every half second if connection was succesfull
  }
  RepeaterIsWorking=true;
}

#else

void setup() {
  Serial.begin(115200);
  Serial.printf("\n\nNAPT not supported in this configuration\n");
  RepeaterIsWorking= false;
  digitalWrite(LED_BUILTIN,1); // led stays off
}

#endif

void loop() {
  if(digitalRead(0)==LOW){
    LittleFS.format();
    ESP.restart();
  }

  while(RepeaterIsWorking){
 unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= delay_time) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }

    // set the LED with the ledState of the variable:
    digitalWrite(LED_BUILTIN, ledState);
  }
  break;
}
}