1 // program WiFiTelnetToSerialWPS.ino, Arduino 1.6.12
   2 /* 
   3   WiFiTelnetToSerial - Example Transparent UART to Telnet Server for esp8266
   4 
   5   Copyright (c) 2015 Hristo Gochkov. All rights reserved.
   6   This file is part of the ESP8266WiFi library for Arduino environment.
   7  
   8   This library is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU Lesser General Public
  10   License as published by the Free Software Foundation; either
  11   version 2.1 of the License, or (at your option) any later version.
  12 
  13   This library is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16   Lesser General Public License for more details.
  17 
  18   You should have received a copy of the GNU Lesser General Public
  19   License along with this library; if not, write to the Free Software
  20   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21 */
  22 
  23 /* 2016-10-17 Rudolf Reuter, push button switch for WPS function added.
  24  *  http://www.wi-fi.org/knowledge-center/faq/how-does-wi-fi-protected-setup-work
  25  *  
  26  *  Once the WiFi credentials are WPS fetched, they are stored,
  27  *  for following use (firmware function).
  28  *  
  29  *  Works on ESP-01 module - Arduino Tools:
  30  *      Board: "Generic ESP8266 Module"
  31  *      Flash Mode: "DIO"
  32  *      Flash Fequency: "40 MHz"
  33  *      CPU Frequency: "80 MHz"
  34  *      Flash Size: "512K (64K SPIFFS)"
  35  *      Debug port: "Disabled"
  36  *      Reset Method: "ck"
  37  *      Upload Speed: "115200"
  38  *  
  39  *  Connection of ESP8266 GPIO0 and GPIO2 for WPS button and LED indicator:
  40  *         Vcc  Vcc       Vcc = 3.3 V
  41  *          |    |         |
  42  *         4K7  4K7       1k0  pull up resistors (3K3 to 10K Ohm)
  43  *          |    |   +-|<|-+   LED red
  44  *          |    |   |
  45  * GPIO0  - +--------+---o |
  46  *               |         | -> | push button switch for WPS function
  47  * GPIO2  -------+-------o |
  48  *
  49  * from http://www.forward.com.au/pfod/ESP8266/GPIOpins/index.html
  50  *
  51  * /!\ There is a '''5 minute''' timeout in the ESP8266 '''!WiFi stack'''. 
  52  * That means, if you have after the first WLAN connection a data traffic pause
  53  * longer than '''5 minutes''', you to have to resync the connection 
  54  * by sending some dummy characters.
  55  */
  56  
  57 #include <ESP8266WiFi.h>
  58 
  59 bool debug = false;  // enable either one
  60 //bool debug = true:
  61 
  62 //how many clients should be able to telnet to this ESP8266
  63 #define MAX_SRV_CLIENTS 1
  64 
  65 WiFiServer server(23);  //  port 23 = telnet
  66 WiFiClient serverClients[MAX_SRV_CLIENTS];
  67 
  68 
  69 bool startWPSPBC() {
  70 // from https://gist.github.com/copa2/fcc718c6549721c210d614a325271389
  71 // wpstest.ino
  72   Serial.println("WPS config start");
  73   bool wpsSuccess = WiFi.beginWPSConfig();
  74   if(wpsSuccess) {
  75       // Well this means not always success :-/ in case of a timeout we have an empty ssid
  76       String newSSID = WiFi.SSID();
  77       if(newSSID.length() > 0) {
  78         // WPSConfig has already connected in STA mode successfully to the new station. 
  79         Serial.printf("WPS finished. Connected successfull to SSID '%s'\n", newSSID.c_str());
  80       } else {
  81         wpsSuccess = false;
  82       }
  83   }
  84   return wpsSuccess; 
  85 }
  86 
  87 void setup() {
  88   Serial.begin(9600);        // adopt baud rate to your needs
  89   //Serial.begin(115200); 
  90   delay(1000);
  91   if (debug) {
  92     Serial.println("\n WPS with push button on GPIO2 input, LOW = active");
  93     Serial.printf("\nTry connecting to WiFi with SSID '%s'\n", WiFi.SSID().c_str());
  94   }
  95 
  96   WiFi.mode(WIFI_STA);
  97   WiFi.begin(WiFi.SSID().c_str(),WiFi.psk().c_str()); // reading data from EPROM, 
  98   while (WiFi.status() == WL_DISCONNECTED) {          // last saved credentials
  99     delay(500);
 100     if (debug) Serial.print(".");
 101   }
 102 
 103   wl_status_t status = WiFi.status();
 104   if(status == WL_CONNECTED) {
 105     if (debug) Serial.printf("\nConnected successful to SSID '%s'\n", WiFi.SSID().c_str());
 106   } else {
 107     // WPS button I/O setup
 108     pinMode(0,OUTPUT);         // Use GPIO0
 109     digitalWrite(0,LOW);       // for hardware safe operation.
 110     pinMode(2, INPUT_PULLUP);  // Push Button for GPIO2 active LOW
 111     Serial.printf("\nCould not connect to WiFi. state='%d'\n", status);
 112     Serial.println("Please press WPS button on your router, until mode is indicated.");
 113     Serial.println("next press the ESP module WPS button, router WPS timeout = 2 minutes");
 114     
 115     while(digitalRead(2) == HIGH)  // wait for WPS Button active
 116       yield(); // do nothing, allow background work (WiFi) in while loops
 117     Serial.println("WPS button pressed");
 118     
 119     if(!startWPSPBC()) {
 120        Serial.println("Failed to connect with WPS :-(");  
 121     } else {
 122       WiFi.begin(WiFi.SSID().c_str(),WiFi.psk().c_str()); // reading data from EPROM, 
 123       while (WiFi.status() == WL_DISCONNECTED) {          // last saved credentials
 124         delay(500);
 125         Serial.print("."); // show wait for connect to AP
 126       }
 127       pinMode(0,INPUT);    // GPIO0, LED OFF, show WPS & connect OK
 128     }
 129   } 
 130 
 131   server.begin();  // telnet server
 132   server.setNoDelay(true);
 133   if (debug) {
 134     Serial.print("\nReady! Use 'telnet ");
 135     Serial.print(WiFi.localIP());
 136     Serial.println(" port 23' to connect");
 137   }
 138 }
 139 
 140 // from Arduino/hardware/esp8266com/esp8266/libraries/ESP8266WiFi/examples/
 141 // (2015-11-15)
 142 
 143 void loop() {
 144   uint8_t i;
 145   //check if there are any new clients
 146   if (server.hasClient()) {
 147     for(i = 0; i < MAX_SRV_CLIENTS; i++) {
 148       //find free/disconnected spot
 149       if (!serverClients[i] || !serverClients[i].connected()) {
 150         if(serverClients[i]) serverClients[i].stop();
 151         serverClients[i] = server.available();
 152         if (debug) {
 153           Serial.print("New client: "); 
 154           Serial.println(i);
 155         }
 156         continue;
 157       }
 158     }
 159     //no free/disconnected spot so reject
 160     WiFiClient serverClient = server.available();
 161     serverClient.stop();
 162   }
 163   //check clients for data
 164   for(i = 0; i < MAX_SRV_CLIENTS; i++) {
 165     if (serverClients[i] && serverClients[i].connected()) {
 166       if(serverClients[i].available()) {
 167         //get data from the telnet client and push it to the UART
 168         while(serverClients[i].available()) Serial.write(serverClients[i].read());
 169       }
 170     }
 171   }
 172   //check UART for data
 173   if(Serial.available()) {
 174     size_t len = Serial.available();
 175     uint8_t sbuf[len];
 176     Serial.readBytes(sbuf, len);
 177     //push UART data to all connected telnet clients
 178     for(i = 0; i < MAX_SRV_CLIENTS; i++) {
 179       if (serverClients[i] && serverClients[i].connected()) {
 180         serverClients[i].write(sbuf, len);
 181         delay(1);  // for multitasking
 182       }
 183     }
 184   }
 185 }