I am just a beginner with programming the Pronto TSU series of remotes. I am trying to understand the Pronto UDP functions so that I can perform a SSDP query to find he IP address of my Roku box. I think I know how to setup the UDP socket and send request but I don't understand how to read back the response so that I can parse if for the IP address.

I need to send the following request using http protocol to 239.255.255.250 port 1900

M-SEARCH * HTTP/1.1
Host: 239.255.255.250:1900
Man: "ssdp:discover"
ST: roku:ecp

I am doing this using the following code

var TARGETADDRESS = "239,255.255.250";
var PORT = 1900;
var aServiceType = "roku:ecp";
var reg;
var socket = new UDPSocket();

req = "M-SEARCH * HTTP/1.1\r\n";
req += "HOST: " + TARGETADDRESS + ":" + PORT + "\r\n";
req += "MAN: \"ssdp:discover\"\r\n";
req += "ST: " + aServiceType + "\r\n";
req += "\r\n";
socket.send(req, TARGETADDRESS, PORT);

I believe this is correct coding to send out the request. What I don't understand is how to get the response back into a string that I can parse to locate the IP address of my Roku. The response I am looking for is something like this

HTTP/1.1 200 OK
Cache-Control: max-age=300
ST: roku:ecp
Location: [Link: 192.168.1.134]
USN: uuid:roku:ecp:P0A070000007

With TCP sockets I would use a socket read to obtain the response, but there does not appear to be a socket read function with UDP socket. The developers guide shows the following example

var s = new UDPSocket(1900);
s.onData = function (aData, aHost, aPort) {
System.print("Received " + aData.length + " bytes");
System.print("Client IP address: " + aHost);
System.print("Client UDP port: " + aPort);
};

If I understand functions correctly aData, aHost and aPort are variables I pass into the function. I don't understand this example. How do I go about getting the data received when the Roku box response to my request. If it was a TCP socket I would do it using

var socket, aData;
socket = new TCPSocket();

socket.onData = function() {
aData = socket.read();
};

There does not appear to be an equivalent read function for UDP sockets. Can someone explain how to do it with a UDP socket. Do I need to set up the response port before I sent the request? Do I need a separate socket for the request and the response?

Thanks,

Ed

[Link: remotecentral.com]

OK,

I finally figured out how to do this. The code below will allow you to query a Roku streaming player such as the Roku 2 and obtain its IP address. Maybe this will be helpful to someone else.

// JavaScript Document

var Timeout = 5000;
var IPAddress; // When routine completes contains IP address of Roku device
var TARGETADDRESS = "239.255.255.250";
var PORT = 1900;
var aServiceType = "roku:ecp";

scheduleAfter(10,sendSearch);

// Open a UDP Socket
//
// This socket used to receive SSDP responses and
// to look for response from Roku device providing
// its IP address
//
// Looking for the following response
// HTTP/1.1 200 OK
// Cache-Control: max-age=300
// ST: roku:ecp
// Location: [Link: 192.168.1.134]
// USN: uuid:roku:ecp:P0A070000007

var socket = new UDPSocket(1900);
socket.onData = function (aData, aHost, aPort)
{
var aResults;

// Split packet data stored in aData at boundaries and
// store each string segment into array elements of aResults

aResults = aData.split(String.fromCharCode(13));

// Verify that line 0 and 1 are correct response for Roku
// device
if (aResults[0].search("HTTP/1.1 200 OK") >= 0 &&
aResults[2].search("ST: roku:ecp") >= 0)
{
IPAddress = aHost;
socket.close();
}
}

// Function querys for the roku IP address by sending an SSDP
// multicast request to IP address 239:255:255:250:1900. The
// request packet is as follows:
// M-SEARCH * HTTP/1.1
// Host: 239.255.255.250:1900
// Man: "ssdp:discover"
// ST: roku:ecp

function sendSearch()
{
var req = "M-SEARCH * HTTP/1.1\r\n";
req += "Host: " + TARGETADDRESS + ":" + PORT + "\r\n";
req += "Man: \"ssdp:discover\"\r\n";
req += "ST: " + aServiceType + "\r\n";
req += "\r\n";
socket.send(req, TARGETADDRESS, PORT);
}

The link above is a very old post and was written before UDP was added to the Pronto. UDP was required for Philips to be able to interface with the Sonos Equipment.