Week

thirteen

networking

  • interface and application programming 💻

    highlights

    How to Node Serial Port to P5
    Beaware of outdated syntax everywhere...

    How to SerialPort attiny data to Unity
    Visualize data to a nightmare.





    • Node Serial







    • to P5.js



    how to Node JS serial to P5

    Code block to acheive it as follows:



    NodeJS (v4.x): Build Serial Socket to Server

                                
    
    //Include Library in Node JS
    
    var SerialPort = require("serialport");
    var WebSocketServer = require("ws").Server;
    
    //Build Serial Socket to Server
    // get port name from the command line:
    
    Serialport.list(function (err, ports) {ports.forEach(function(port) {console.log(port.comName);});
    });
    
    var myPort = new SerialPort("/dev/tty.usbmodem1412311", 9600);
    var Readline = SerialPort.parsers.Readline; // make instance of Readline parser
    var parser = new Readline(); // make a new parser to read ASCII lines
    myPort.pipe(parser); // pipe the serial stream to the parser
    
    
    myPort.on('open', showPortOpen);
    parser.on('data', readSerialData);
    myPort.on('close', showPortClose);
    myPort.on('error', showError);
    
    function showPortOpen() {
       console.log('port open. Data rate: ' + myPort.baudRate);
    }
    
    function showPortClose() {
       console.log('port closed.');
    }
    
    function showError(error) {
       console.log('Serial port error: ' + error);
    
    function readSerialData(data) {
       console.log(data);
    
    
    // don't put below code in before you build the server in the next step
        if (connections.length > 0) {
         broadcast(data);
       }
    }
    
                                
                            



    seems like working. However if you see the weird ❓like me, it means that you are using serial.write rather than serial. println, which will cause you trouble in the later parsing process.



    NodeJS (v4.x): Build Web Socket to Server

                                
    
    //Build Server for WebVisualization
    
    var SERVER_PORT = 8081;               // port number for the webSocket server
    var wss = new WebSocketServer({port: SERVER_PORT}); // the webSocket server
    var connections = new Array;          // list of connections to the server
    
    
    
    wss.on('connection', handleConnection);
    
    function handleConnection(client) {
     console.log("New Connection"); // you have a new client
     connections.push(client); // add this client to the connections array
    
     client.on('message', sendToSerial); // when a client sends a message,
    
     client.on('close', function() { // when a client closes its connection
     console.log("connection closed"); // print it out
     var position = connections.indexOf(client); // get the client's position in the array
     connections.splice(position, 1); // and delete it from the array
     });
    }
    
    myPort.write("Hello");
    
    function sendToSerial(data) {
     console.log("sending to serial: " + data);
     myPort.write(data);
    }
    
    function broadcast(data) {
     for (myConnection in connections) {   // iterate over the array of connections
      connections[myConnection].send(data); // send the data to each connection
     }
    }
    
    
    
                                
                            



    html: listen to server and basic draw with p5 Download basic p5 integrated html template



    if server is opened, no readings or animation is drawn. And your page end up like above pic. For my case, it could be outdated syntax on importing npm serialport. According to your node js version, require serial port can either be "" or '' or ' ' + certain things. Another thing worth notice is that p5 library's struture is changing a lot too. If you are revising someone else's code, you have to make sure using



    using readings as the spike range of the spiky sphere.