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

1. Setup a TCP network server
   
2. Setup a TCP client
   
3. Modify ESP8266WiFi_0v25.js to do UDP and TCP
   
4. Use UDP to allow clients to find the server IP address
   

5. The UDP/TCP client.

6. Setup a TCP network server
   The TCP server and client code are based on the examples listed under the Sockets section of
   http://www.espruino.com/Internet
   The following code sets up a TCP server on port 9988.
   You will need to edit:
   //var Hardware=0; //Espruino board
   var Hardware =1; //PICO
   var SSID="ssid";
   var key= "router passcode";

When a client connects two commands are accepted “LED On” and “LED Off”

//netServer3.js
//2 Oct 2016
//espruino board with ESP8266
//PICO  with ESP8266
var Sport=9988;
//var Hardware=0; //Espruino board
var Hardware =1; //PICO
var SSID="ssid";
var key= "router passcode";
var Serial;
var MyIP="";
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);MyIP=ip;
      console.log("Wi-Fi Connected");
// Now you can do something, 
serve();

////////////////////////////////////////////////////////////
     });
    });
  });
});
}//end test

var x;
console.log("Start");
x=test();
if(x!==0)console.log("Try again");//error seen

if(x===0) console.log("Exit Seen");

//xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
function serve(){
 var data;
 var server = require("net").createServer(function(c) {
  // A new client has connected
//  c.write("Hello");
/*  c.on('data', function(data) {
    console.log(">"+JSON.stringify(data));
  });
*/
   c.on('close',function(d){
   console.log("Close "+d);
   data=c.read(c.available());
   console.log(data);
   c.write(data);
     if(data==="LED Off"){
      digitalWrite(B12,0); //B12 is green LED
     }
     if(data==="LED On"){
      digitalWrite(B12,1);
     }
  });
  c.end();
});
server.listen(Sport);

}

The TCP server output:

>echo(0);
Start
Start connection process
Try again
=undefined
Reset the ESP8266
Connecting to WiFi
IP=  192.168.1.3
null
Wi-Fi Connected
>

At this point I disconnect the WebIDE from the TCP server hardware and reconnect using putty.
Make a note of the server IP addess.

1 Attachment

• netServer3.js