#!/usr/bin/env python
# -*- coding: utf8 -*-

import RPi.GPIO as GPIO
import MFRC522



# [1] Create an object of the class MFRC522
GPIO.setwarnings(False);
MIFAREReader = MFRC522.MFRC522()

# [2] Scan for cards
(status,TagType) = MIFAREReader.MFRC522_Request(MIFAREReader.PICC_REQIDL)

# [3] If no card found -> exit 1
if status != MIFAREReader.MI_OK:
	print 127;
	exit(127);

# [4] Get the UID of the card
(status,uid) = MIFAREReader.MFRC522_Anticoll()

# [5] If no UID read -> exit 1
if status != MIFAREReader.MI_OK:
	print 127;
	exit(127);

# [6] Print UID
hexCode = [];
hexCode.append( str(hex(uid[0]))[2:] );
hexCode.append( str(hex(uid[1]))[2:] );
hexCode.append( str(hex(uid[2]))[2:] );
hexCode.append( str(hex(uid[3]))[2:] );


if( len(hexCode[0]) == 1 ):
	hexCode[0] = '0' + hexCode[0];

if( len(hexCode[1]) == 1 ):
	hexCode[1] = '0' + hexCode[1];

if( len(hexCode[2]) == 1 ):
	hexCode[2] = '0' + hexCode[2];

if( len(hexCode[3]) == 1 ):
	hexCode[3] = '0' + hexCode[3];



suid = hexCode[0];
suid += '-' + hexCode[1];
suid += '-' + hexCode[2];
suid += '-' + hexCode[3];

print suid;
exit(0);