Using UPD to find IP addresses for a TCP network in 5 parts.

1. Setup a TCP client
   This code sets up the TCP client on port 9988.
   The console is redirected to the Loopback to allow the WebIDE to act as a simple menu system.
   You will need to edit the hardware flag , ssid and router passcode.
   Additionally you have to hardcode the IP address of the server. (we will fix this with UDP later)

   //netclient3.js
   //2 Oct 2016
   //espruino board with ESP8266
   //PICO  with ESP8266
   var IP="192.168.1.3";
   var Sport=9988;
   //var Hardware=0; //Espruino board
   var Hardware =1; //PICO
   var SSID="ssid";
   var key= "router passcode";
   var Serial;
   function test(){
   if(Hardware===1)Serial=Serial2;
   if(Hardware===0)Serial=Serial4;
   if(Hardware===1){
   digitalWrite(B9,1); // enable on Pico Shim V2
   Serial.setup(115200, { rx: A3, tx : A2 }); //Pico
   }
   if(Hardware===0)Serial.setup(115200, { rx: C11, tx : C10 }); 
   //espruino board
   console.log("Start connection process");
   var wifi = require("ESP8266WiFi_0v25").connect(Serial, function(err) {
   if (err)return 1;// throw err;
   console.log("Reset the ESP8266");
   wifi.reset(function(err) {
   if (err)return 1;// throw err;
   console.log("Connecting to WiFi");
   wifi.connect(SSID,key, function(err) {
     if (err)return 1;//throw err;
     wifi.getIP(function(l,ip){console.log("IP= ",ip,"\n\r"+l);});
     console.log("Wi-Fi Connected");
   // Now you can do something,
   menu();
   ////////////////////////////////////////////////////////////
   });
   });
   });
   }//end test
   //xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
   function sendit(msg){
   var reply="";
   var client = require("net").connect({host: IP, port: Sport}, function() {
   //  console.log('client connected');
   client.write(msg);
   client.on('data', function(data) {
   reply+=data;
   console.log(">"+JSON.stringify(data));
   });
   client.on('end', function() {
   //    console.log('client disconnected');
   return reply;
   });
   });
   }
   
   ////////////////////////////////////////////////////////////////////////
   var sst="";
   //Menus
   menu=function(){
   USB.print(" \n\r");
   USB.print("Select using digit and return key\n\r");
   USB.print("1 LED Off\n\r");
   USB.print("2 LED On\n\r");
   USB.print("0 Exit\n\r");
   };
   parsecmd=function(){
   USB.print("\n\r");
   switch(this.sst.charAt(0)){
   case "1"://LED off
    sst="";
    USB.print("LED Off\n\r");
    sendit("LED Off");
   break;
   case "2"://LED On
    USB.print("LED On\n\r");
    sst="";
    sendit("LED On");
   break;
   case"0"://Exit
    LoopbackA.print("USB.setConsole();\n\r");
    sst="";
    USB.print("Exit\n\r");
   break;
   default:
    menu();
   break;
   }//end switch sst
   };//end parsecmd
   //input cmd from terminal,send it to parsecmd()
   USB.on('data', function (data) {
   var i;
   sst+=data;
   USB.print(data);
   if(sst.length>0)
   if(sst.charAt(sst.length-1)==="\r")parsecmd();
   });
   //Espruino replies here
   LoopbackA.on('data',function(data){
   USB.print(data); //sending data to terminal
   });
   /////////////////////////
   setTimeout(function () {
   var x;
   console.log("Start");
   LoopbackB.setConsole();
   x=test();
   if(x!==0)console.log("Try again");//error seen
   if(x===0) console.log("Exit Seen");
   }, 1000);
   

And the WebIde output:

>echo(0);
=undefined
Start
-> LoopbackB
<- USB
Start connection process
Try again
Reset the ESP8266
Connecting to WiFi
>
Select using digit and return key
1 LED Off
2 LED On
0 Exit
Wi-Fi Connected
IP=  192.168.1.4
null
>1
LED Off
2
LED On
1
LED Off
0
Exit
<- LoopbackB
=undefined
=undefined
>USB.setConsole();
-> USB

Notice that the 0 Exit restores the console to the USB port.
The Server output on the Putty terminal:

Close false
LED Off
Close false
LED On
Close false
LED Off
>

1 Attachment

• netClient3.js