send mouse positions to gcode using node js

gistfile1.txt

/*

This is a node.js application. It relies on "npm serialport".

Save it as penwriter.js

Run it using

  node penwriter.js
  
Visit it with a browser such as 

  http://127.0.0.1:9876
  
You will get a blank screen. If you open the browser developer debug console you will see that when you press the mouse down and move that it will report the mouse positions. It also sends them back to the server and pipes them out to the serial device.

You will need to hack the code appropriately to write the correct stuff to the correct serial port.




*/


var homepage = "\
<script>                                                \n\
 var ispressed = 0;                                     \n\
 document.ontouchstart=function(){ispressed=1}          \n\
 document.ontouchend=function(){ispressed=0}            \n\
 document.onmousedown=function(){ispressed=1}           \n\
 document.onmouseup=function(){ispressed=0}             \n\
 document.onmousemove=function(event){                  \n\
   if(!ispressed)return;                                \n\
   var query = '/xy?x='+event.pageX+'&y='+event.pageY;  \n\
   var req = new XMLHttpRequest();                      \n\
   req.open('GET',query,false);                         \n\
   req.send();                                          \n\
   console.log(event.pageX+'...'+event.pageY);          \n\
 }                                                      \n\
</script>                                               \n\
";

// an http hserver
var http = require('http');
var url = require('url');
function start_webserver() {
  http.createServer(function(request,response) {
    var query = url.parse(request.url);
    if(!query.query) {
      console.log("A short request - assuming it is for the client\n");
      response.writeHead(200);
      response.write(homepage);
      response.end();
      return;
    } else {
      var parts = query.query.split("&");
      var part1 = parts[0].split("=");
      var part2 = parts[1].split("=");
      var x = part1[1];
      var y = part2[1];
      console.log("x = " + x + " y = " + y );
      serial_write(x,y);
      response.writeHead(200);
      response.write("delicious thanks\n");
    }
    response.end();
  }).listen(9876);
};

// a serial port
var SerialPort = require("serialport").SerialPort;
var ser = 0;
function serial_write(x,y) {
  if(!ser) return;
  console.log("writing data to serial port");
  var data = "X"+x+"\n";
  ser.write(data,function(err,results) {
  });
  var data = "Y"+Y+"\n";
  ser.write(data,function(err,results) {
  });
}

// start web server if serial opens
function start_serial() {
  ser.on("open",function() {
    console.log("successfully opened serial port, now starting web server");
    start_webserver();
  });
}

/*
try {
  ser = new SerialPort("/dev/tty-usbserial1", { baudrate: 57000 });
  start_serial();
} catch(error) {
  console.log("no such port - running server anyway\n");
}
*/

start_webserver();