server.js

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);

/* Main server startup stuff */
if(process.argv[2] == "serialport" ) {

  if(process.argv[3]){
    serialPortMode(process.argv[3]);
  } else {
    console.log('please include a serial port');
    process.exit();
  }
} else if(process.argv[2] == "websocket" ) {
  webSocketMode();
} else if(process.argv[2] == "playback" ) {
  if(process.argv[3]){
    playbackMode(process.argv[3]);
  } else {
    console.log('please include a file');
    process.exit();
  }
} else {
  console.log("Please specify a mode: serialport <port> | websocket | playback <file>");
  process.exit();
}

/* Serve Files */
app.get('/ShareTechMono-regular.ttf', function(req, res){
  res.sendFile(__dirname + '/ShareTechMono-regular.ttf');
});

app.get('/', function(req, res){
  res.sendFile(__dirname+'/index.html');
});

app.get('/processing.js', function(req, res){
  res.sendFile(__dirname+'/processing.js');
});

app.get('/rocket.pde', function(req, res){
  res.sendFile(__dirname+'/rocket.pde');
});

app.get('/style.css', function(req, res){
  res.sendFile(__dirname+'/style.css');
});

app.get('/visualization-run.js', function(req, res){
  res.sendFile(__dirname+'/visualization-run.js');
});

app.get('/logo.png', function(req, res){
  res.sendFile(__dirname+'/logo.png');
});

/* server status */
io.on('connection', function(socket){
  console.log('a user connected');
  socket.emit('data', 123);
});

http.listen(3000, function(){
  console.log('listening on *:3000');
});


/* This Visualization service can be set up in different modes! */

function playbackMode(file){
  // playback mode!!!
  var fs = require('fs');

  // default state
  var rocket_state = {};// = {'pitch':0, 'alt':0, 'temp':0, 'roll':0, 'heading':0, 'xLin':0, 'yLin':0, 'zLin':0};
  var playback_file;
  var counter = 0;
  var max_count = 0;
  var msg_type = ['IGNORE', 'ERROR', 'WARNING', 'INFO', 'GPS', 'IMU', 'POWER'];

  fs.readFile(file, 'ascii', function(err, contents) {
    console.log("file imported");
    playback_file = contents.split("\n");
    max_count = playback_file.length;
  });

  setInterval(function(){
    if(playback_file){
      var line = playback_file[counter];
      //console.log(line);
      var line_code = line.charCodeAt(0).toString(16);
      //console.log(line_code + " " + msg_type[line_code]);
      //console.log(line_code);
      line = line.substring(1); // Removes line code.
      switch (line_code) {
        case '3':
          // TODO: make a separate line code for actual data that isn't INFO -- this must be done payload side
          //console.log("INFO");
          line = line.match(/[-]{0,1}[\d]*[\.]{0,1}[\d]+/g);
          //console.log(line);
          if(line){
            if (line.length == 3) {
              rocket_state.temp = line[0];
              rocket_state.pressure = line[1];
              rocket_state.alt = line[2];
            }
          }

          break;
        case '4':
          //console.log("GPS");
          //console.log(line);
          break;
        case '5':
          console.log("IMU");
          line = line.split(" ");
          console.log(line);
          rocket_state.roll = line[2];
          rocket_state.pitch = line[1];
          rocket_state.heading = line[0];

          console.log("################### " + counter);
          // roll pitch heading
          break;
        default:

      }
      counter = (counter + 1) % max_count;
    }
    io.sockets.emit('data', rocket_state);
  }, 100);

  console.log('after calling readFile');
}

function serialPortMode(port){
  // This mode was originally used at Maker Faire 2015, where the payload was connected directly over USB serial.
  // TODO: i couldn't successfully install SerialPort so idk if this even works

  var SerialPort = require("serialport").SerialPort

  var serialPort = new SerialPort(port, {
    baudrate: 115200
  });

  serialPort.on("open", function () {
    console.log('open');
    var cmd = '';
    serialPort.on('data', function(data) {
      cmd = cmd.concat(data.toString());
      if(cmd.indexOf('\n', cmd.length - 1) !== -1) {
        try {
          var obj = JSON.parse(cmd);
          console.log(obj);
          io.sockets.emit('data', obj);
        } catch (e) {
          console.log(cmd);
        }
        cmd = '';
      }
    });
  });
}

function webSocketMode(){
  // This mode was used with the HorizonTracker payload project, @poojpooj Summer 2017
  // TODO: I also didn't test this
  var WebSocketServer = require('ws').Server;
  var server = require('http').createServer();
  var wss = new WebSocketServer({server: server, path: '/foo'});
  wss.on('connection', function(ws) {
    console.log('/foo connected');
    ws.on('message', function(data, flags) {
      if (flags.binary) { return; }
      console.log('>>> ' + data);
      var obj = {'pitch':0, 'alt':0, 'temp':0, 'roll':parseFloat(data), 'heading':0, 'xLin':0, 'yLin':0, 'zLin':0};
      io.sockets.emit('data', obj);
    });
    ws.on('close', function() {
      console.log('Connection closed!');
    });
    ws.on('error', function(e) {
    });
  });
  server.listen(8126);
  console.log('Listening on port 8126...');
}