Once you have the PCB done, solder it all up and program the chip with your fav. programmer. HEX file attached.
For debugging, you can connect pin 2 (GPIO5) and a ground pin to the serial port of a PC's Rx and ground @ 9600 baud to see the actual tag values and what the chip is doing. However, it may not work properly on all PC's without the addition of a max232 chip as it is only pseudo RS232 and not true levels. Not that i have come across any in recent times.