This example should be run on any other Node.js supported platform, with changing SerialPort name. The tablet is used to log-in Raspberry Pi to start the app, for demonstrate only, not a part of the example.
You have to install socket.io and serialport modules for Node.js:
$ npm install socket.io
$ npm install serialport
app.js
var app = require('http').createServer(handler),
io = require('socket.io').listen(app),
fs = require('fs'),
os = require('os'),
sp = require("serialport");
//init for SerialPort connected to Arduino
var SerialPort = sp.SerialPort
var serialPort = new SerialPort('/dev/ttyACM0',
{ baudrate: 9600,
dataBits: 8,
parity: 'none',
stopBits: 1,
flowControl: false
});
serialPort.on("open", function () {
console.log('serialPort open');
serialPort.write("LEDOFF\n");
});
//Display my IP
var networkInterfaces=os.networkInterfaces();
for (var interface in networkInterfaces) {
networkInterfaces[interface].forEach(
function(details){
if (details.family=='IPv4'
&& details.internal==false) {
console.log(interface, details.address);
}
});
}
//All clients have a common status
var commonStatus = 'ON';
app.listen(8080);
function handler (req, res) {
fs.readFile(__dirname + '/index.html',
function (err, data) {
if (err) {
res.writeHead(500);
return res.end('Error loading index.html');
}
res.writeHead(200);
res.end(data);
});
}
io.sockets.on('connection', function (socket) {
//Send client with his socket id
socket.emit('your id',
{ id: socket.id});
//Info all clients a new client caaonnected
io.sockets.emit('on connection',
{ client: socket.id,
clientCount: io.sockets.clients().length,
});
//Set the current common status to the new client
socket.emit('ack button status', { status: commonStatus });
socket.on('button update event', function (data) {
console.log(data.status);
//acknowledge with inverted status,
//to toggle button text in client
if(data.status == 'ON'){
console.log("ON->OFF");
commonStatus = 'OFF';
serialPort.write("LEDON\n");
}else{
console.log("OFF->ON");
commonStatus = 'ON';
serialPort.write("LEDOFF\n");
}
io.sockets.emit('ack button status',
{ status: commonStatus,
by: socket.id
});
});
//Info all clients if this client disconnect
socket.on('disconnect', function () {
io.sockets.emit('on disconnect',
{ client: socket.id,
clientCount: io.sockets.clients().length-1,
});
});
});
index.html
<html>
<meta name="viewport" content="width=device-width, user-scalable=no">
<head></head>
<body>
<hi>Test Node.js with socket.io</hi>
<form action="">
<input type="button" id="buttonToggle" value="ON" style="color:blue"
onclick="toggle(this);">
</form>
<script src="/socket.io/socket.io.js"></script>
<script>
var socket = io.connect(document.location.href);
var myId;
socket.on('on connection', function (data) {
console.log("on connection: " + data.client);
console.log("Number of client connected: " + data.clientCount);
});
socket.on('on disconnect',function(data) {
console.log("on disconnect: " + data.client);
console.log("Number of client connected: " + data.clientCount);
});
socket.on('your id',function(data) {
console.log("your id: " + data.id);
myId = data.id;
});
socket.on('ack button status', function (data) {
console.log("status: " + data.status);
if(myId==data.by){
console.log("by YOU");
}else{
console.log("by: " + data.by);
}
if(data.status =='ON'){
document.getElementById("buttonToggle").value="ON";
}else{
document.getElementById("buttonToggle").value="OFF";
}
});
function toggle(button)
{
if(document.getElementById("buttonToggle").value=="OFF"){
socket.emit('button update event', { status: 'OFF' });
}
else if(document.getElementById("buttonToggle").value=="ON"){
socket.emit('button update event', { status: 'ON' });
}
}
</script>
</body>
</html>
Arduino code
#include <Esplora.h>
#include <TFT.h>
#include <SPI.h>
int MAX_CMD_LENGTH = 10;
char cmd[10];
int cmdIndex;
char incomingByte;
void setup() {
EsploraTFT.begin();
EsploraTFT.background(0,0,0);
EsploraTFT.stroke(255,255,255); //preset stroke color
//Setup Serial Port with baud rate of 9600
Serial.begin(9600);
//indicate start
Esplora.writeRGB(255, 255, 255);
delay(250);
Esplora.writeRGB(0, 0, 0);
cmdIndex = 0;
}
void loop() {
if (incomingByte=Serial.available()>0) {
char byteIn = Serial.read();
cmd[cmdIndex] = byteIn;
if(byteIn=='\n'){
//command finished
cmd[cmdIndex] = '\0';
Serial.println(cmd);
cmdIndex = 0;
if(strcmp(cmd, "LEDON") == 0){
Serial.println("Command received: LEDON");
Esplora.writeRGB(255, 255, 255);
}else if (strcmp(cmd, "LEDOFF") == 0) {
Serial.println("Command received: LEDOFF");
Esplora.writeRGB(0, 0, 0);
}else{
Serial.println("Command received: unknown!");
}
}else{
if(cmdIndex++ >= MAX_CMD_LENGTH){
cmdIndex = 0;
}
}
}
}
Cross post with Arduino-er
Next: Bi-directional control between Raspberry Pi + Node.js + Arduino
No comments:
Post a Comment