Build Instructions

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• 1

  Step 1

  Installation and Configuration

  • Define the configuration in the LTPS Web Interface
  • Login to the LTPP3 board from the SSH client
  • Install NPM and other tools as required
  • Install the app:

  git clone https://github.com/tibbotech/tps-gpio-tutorials
  cd tps-gpio-tutorials
  npm install .
  cd one-led

• 2

  Step 2

  • Launch the app:

  • node server

• 3

  Step 3

  server.js

  Comments in the code explain how it works

  // Requires HTTP as WebSocket server modules
  const express = require("express");
  const app = express();
  const http = require('http').Server(app);
  const io = require('socket.io')(http);
  const gpio = require("@tibbo-tps/gpio");
  
  // Serves static assets from the 'public' folder
  app.use("/", express.static('public'));
  
  const led = gpio.init("S15A");
  
  if(led.getDirection() === "input"){
      led.setDirection('output');
      led.setValue(1);
  }
  
  // Listens to the incoming WebSocket connection
  var clients = io.on('connection', function(socket){
      // When the connection is established
      console.log('USER CONNECTED');
  
      // Reads I/O line state..
      // ..and broadcasts it to all the connected clients
      var value = led.getValue();
  
      clients.emit('tps:state:changed', value);
  
      // When any of the connected clients require a change of the line state
      socket.on('web:state:changed', function(value){
          // Changes the line state...
          led.setValue(value);
  
          //.. and broadcasts it to all the clients
          clients.emit('tps:state:changed', value);
      });
  
      socket.on('disconnect', function(){
          console.log('USER DISCONNECTED');
      });
  });
  
  // Runs HTTP server on :3000 port
  http.listen(3000,function(){
      console.log("LISTENING"); 
  });

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