As part of a mini side project I’ve been working on lately I wanted to get a desktop Adobe Air application reading RFID tags with Arduino. I’m by no means an expert at all this, but I learnt a lot while doing this so I thought I’d pass the knowledge on.

Ingredients:

These are the elements I used to make this all work:

• Arduino (I got mine from Oomlout, its a good little starter kit)
• RFID module (I used the Seeed Studio ‘RDM 125KHz card mini-module‘)
• At least one 125KHz RFID tag (I used this one from SparkFun)
• AS3glue (You can download that here)
• Flash

Step 1, Wiring up the RFID module to the Arduino:

This part is simple, especially if you have a breadboard. Basically there are 3 parts to the RFID module, the Data/power, the antenna and a light for when it reads a valid tag.

Here’s a diagram of the connections from the RFID module:

Connected to the Arduino:

Once this is all connected you can test its working by scanning your RFID tag, the LED should light up when it’s read.

Step 2, The Arduino code:

Now we need to write the code and upload to the Arduino. Like the wiring, it’s actually fairly simple. When the tag is read by the RFID module the tag’s id is sent to Arduino as bytes. We just need to loop through those bytes and forward that id to the computer using Firmata. All the code for Firmata is already added with the Arduino software, so you just need to include it in your code.

The code to do all this is below, simply upload it to your Arduino:

#include 
#include 
#define rxPin 2
#define txPin 3
 
char code[20];
int val = 0;
int bytesread = 0;
 
SoftwareSerial RFID = SoftwareSerial(rxPin, txPin);
 
void setup()
{
  Serial.begin(9600);
  RFID.begin(9600);
  pinMode(rxPin, INPUT);
  pinMode(txPin, OUTPUT);
}
 
void loop()
{
  val = 0;
  bytesread = 0;
 
  while(bytesread < 12)   
  {     
     val = RFID.read();
     if(val == 3)
     {
        break;
     }
     if(val != 2)
     {
       code[bytesread] = val;
       bytesread++;
     }
   }
   if(bytesread >= 12)
   { 
    Serial.print(START_SYSEX, BYTE); 
    Serial.print(code);
    Serial.print(END_SYSEX, BYTE);
  }
}

If that all goes well you should see something like this in the serial monitor when scanning a RFID tag (the tag’s id is between the first and last characters, so in this case the tag’s id is 4500B89EACCF):

Step 3, Going from Arduino to Flash/Air:

I used the AS3glue library (download here) to handle the communication between Arduino and Flash, but it can’t receive message directly from Arduino- that’s where Serproxy comes in.

You’ll find Serproxy in the AS3glue zip file and you’ll need to amend some settings before it’ll work. You can edit the settings by opening serproxy.cfg in any simple text editor. Its well annotated so it should be simple to setup for your system but there is one thing you’ll need to change differently to the recommendations. comm_baud needs to be set to 9600 (not 57600). Also you will probably want to set the timeout to something higher, I went with 86400 (24 hours).

For the AS3 code you need to import net.eriksjodin.arduino.Arduino and net.eriksjodin.arduino.ArduinoSysExEvent. Then create a new instance of Arduino, add an ArduinoSysExEvent.SYSEX_MESSAGE event listener and read event data to get the tag. Simple as that!

package  
{
	import flash.display.MovieClip;
	import flash.events.Event;
	import flash.events.IOErrorEvent;
	import net.eriksjodin.arduino.Arduino;
	import net.eriksjodin.arduino.events.ArduinoSysExEvent;
 
	public class RFID extends MovieClip
	{
		private var arduino:Arduino;
 
		function RFID()
		{
			setup();
		}
 
		public function setup():void 
		{
			arduino = new Arduino("127.0.0.1", 5331);
			arduino.addEventListener(Event.CONNECT, onSocketConnect);
			arduino.addEventListener(IOErrorEvent.IO_ERROR, onSocketError);
			arduino.addEventListener(ArduinoSysExEvent.SYSEX_MESSAGE, onReceiveSysEx); 
		}
 
		private function onSocketConnect(e:Event):void 
		{
			trace('Connected to Arduino');
		}
 
		private function onSocketError(e:IOErrorEvent):void 
		{
			trace('Error connecting to Arduino, is serproxy running?');
		}
 
		private function onReceiveSysEx(e:ArduinoSysExEvent):void 
		{
			var newCode:String = String(e.data);
			trace("Received tag: " + e.data);
		}
	}
}

You’ll need serproxy running for it to all work and when flash connects you should get this message:

Then when you scan your RFID tag Flash should trace:

Connected to Arduino
Received tag: 4500B89EACCF

All done!

Well I hope that was easy enough to follow. Have fun!

Banksy once said “Most things look better when you put them in a circle”, but he probably wasn’t thinking about website navigation when he did. Its rare to see a menu based on a circle and for good reason, they tend not to be very user friendly (especially on a website that needs to be accessible) and often take up too much room on a page. Making content fit around them (and look good) can be a pain. That said it doesn’t mean there aren’t any good examples of circular navigation.

Below are 5 examples that I’ve come across, they’re all built in Flash, but I wouldn’t mind betting there are some good examples of circle based menus built in HTML5 that I’ve not spotted. If you know of any sites worthy of this list let me know in the comments.

Roger & Gallet

Self Titled

The Toke

Instantanés de Provence

Zeebee

I watch a lot of videos online and I’d like to share the good ones with you guys. I’ll try post new videos on a regular basis, but if I see no good videos then I wont post, only the good ones make it here!

Storm

Samsung Galaxy S II advert

Meet Buck

The app is fairly simple, it has 3 rounds of increasingly harder questions about anything nerdy, like computers, mobile, internet and more. At the end you are given a ‘nerd grade’ which ranges from D- to A+.

Its not fully finished yet, here’s my to do list:

- More questions
- Share on Facebook/Twitter
- Scoreboard

I love to know your thoughts, or if you came across a bug please let me know in the comments. Also if you have a question suggestions I’d like to hear them (it turns out making up hundreds of questions is quite hard work!).

When making this blog I came across an issue when viewing my site on the iPad. Gaps between background images were appearing, different gaps at different zoom levels. The issue is with the way iOS rescales all the elements on the page to fit the smaller screen. When it does this it often leaves a 1 pixel gaps between divs.

The fix is to add -1px to the margin where the lines are appearing, that way the divs overlap slightly. So in my case I needed to add -1px to the top margins:

margin-top: -1px;

Hope that helps!

In January I made a little Android app called Chalkboard Clock. I made it for 2 reasons, firstly I wanted to know the process for getting an app to market and I also wanted to test Air for Android, see its performance.

The app itself is fairly simple, you draw the numbers 1 to 9 and it then redraws those numbers to tell you the time, updating every minute. The idea being you put your phone into a dock and have this run like a screensaver. Its not that useful and I wasn’t really expecting anyone to download it but to my surprise it recently surpassed a 1000 downloads! Now I know thats not that many in the big scheme of things but it is way more than I thought. Also what’s quite nice is most comments are requests for a widget mode, while its not praise its also not a complaint

My experience with Air for Android can be summed up like so… good but could be a better. Its early days at the moment but would be good to get support to make widgets soon. Also would be good if users could move Air to the SD card, I know at least one person that hasn’t been able to install my tiny 228kb app because they have no room for the rather more chunky 16.9mb Air app. [EDIT] : It is now possible with Air 2.7 to move the app to the SD card!

You can download Chalkboard Clock here.

I’m working on a new app which will hopefully find its way onto Android and iOS before too long. I’ll let you know how it goes.