Socket.IO Arduino Client for Adafruit CC3000

This was based off Bill Roy’s Ethernet shield Socket.IO version which I then edited to support the Adafruit CC3000 board.

Kevin's documentation is reproduced hereinafter, with changes as needed.

This library only works with Socket.IO versions 9.x.x and below. There was a change in the protocol that makes it difficult to communicate with the new server. Fixes coming soon.

Caveats

This library doesn't support every inch of the Websocket spec, most notably the use of a Sec-Websocket-Key. Also, because Arduino doesn't support SSL, this library also doesn't support the use of Websockets over https. If you're interested in learning more about the Websocket spec I recommend checking out the Wikipedia Page. Now that I've got that out of the way, I've been able to successfully use this to connect to several hosted Websocket services, including: echo.websocket.org and pusherapp.com.

Installation instructions

Clone this repo into your Arduino Sketchbook directory under libraries, then restart the Arduino IDE so that it notices the new library.

How To Use This Library

/**
 * Includes
 */
#include <Adafruit_CC3000.h>
#include <SocketIOClient.h>
#include <SPI.h>
#include "utility/debug.h"

/**
 * Network config
 */
#define WLAN_SSID "ssid"
#define WLAN_PASS "password"
#define WLAN_SECURITY WLAN_SEC_WPA2

/**
 * Pins
 */
#define ADAFRUIT_CC3000_IRQ   3
#define ADAFRUIT_CC3000_VBAT  5
#define ADAFRUIT_CC3000_CS    10

Adafruit_CC3000 cc3000 = Adafruit_CC3000(ADAFRUIT_CC3000_CS, ADAFRUIT_CC3000_IRQ, ADAFRUIT_CC3000_VBAT, SPI_CLOCK_DIV2); // you can change this clock speed

SocketIOClient client;

void ondata(SocketIOClient client, char *data) {
  Serial.println(F("Incoming data!"));
  Serial.println(data);
  Serial.println(F("----------"));
}

void setup() {
  InitializeCC30000();

  client.setDataArrivedDelegate(ondata);
  if (!client.connect(cc3000, "example.com", 80)) {
    Serial.println(F("Not connected."));
  }
}

void loop() {
  client.monitor(cc3000);
  client.sendEvent("info", "foobar");
  delay(2000);
}

void InitializeCC30000(void){
  // initialise the module
  Serial.println(F("Initializing..."));

  // initialize CC3000 chip
  if (!cc3000.begin()) {
    Serial.println(F("Couldn't begin()! Check your wiring?"));
    while(1);
  }

  // optional SSID scan
  if (!cc3000.connectToAP(WLAN_SSID, WLAN_PASS, WLAN_SECURITY)) {
    Serial.println(F("Failed!"));
    while(1);
  }

  Serial.println(F("Connected!"));

  // wait for DHCP to complete
  Serial.println(F("Request DHCP"));
  while (!cc3000.checkDHCP()) {
    delay(100);
  }  
}

It should be fairly easy from then to communicate with the Node backend. Just run:

npm install [email protected] && npm install [email protected]

Though those might be the old versions of the libraries, they are the currently supported ones because of a Socket.IO protocol change in 1.0. You can try getting Express to work at version 4.0, but I have not tried to test it yet.

An example Node server might look like:

var io = require('socket.io');
var express = require('express');

var app = express(),
    server = require('http').createServer(app),
    io = io.listen(server);

server.listen(80);

io.sockets.on('connection', function (socket) {
  socket.emit('yo', { hello: 'world' });
  socket.on('info', function (data) {
    console.log(data);
  });
});

// serve HTML files in the `public` directory.
app.use(express.static(__dirname + '/public'));