RFID Manchester Decoding

Hi all, new to the forum!

Has anyone done this on an arduino using the u2270B? I have been working on an RFID project in college. It's based on the u2270B base station read/write IC. I'm using tk5551 tags to test. Its been a avery interesting project!

I have copied the datasheet application 1 schematic and used it to design and build a PCB. I designed it to work as a shield for the arduino. I etched and built the PCB and Its working well. The output from the u2270B is 5V DC and when a tag is brought in proximity i can see the manchester code on a scope.

So i'm happy with how its working. The only problem now is i have looked at sample code for other projects but they all seem to be using serial comms to transmit tag data to the arduino. for example, parallax and the ID-12 or ID-20 boards. The parallax board has an 18F mcu on it which is decoding the manchester code and sending it back as serial data to the arduino.

Has anybody got any sample code or any info on how to decode the manchester code from the u2270B chip? I have looked at the App note and such and i think the way to do it would be as follows...

Run a timer, have a pin state change interupt so that when the pin connected to u2270B OUTPUT detects a change it can start detecting edges and time them to determine if its a 1 or a 0.

There is a lot to do there and i'm trying to get my head around it. I've looked at PinChangeInt but seems kind of complex!

Has anyone done this on an arduino using the u2270B? any info would be appreciated! Regards, Dean