diff --git a/trunk/NfcEmul/nfcemulator.c b/trunk/NfcEmul/nfcemulator.c
new file mode 100644
index 0000000..ec474e4
--- /dev/null
+++ b/trunk/NfcEmul/nfcemulator.c
@@ -0,0 +1,396 @@
+/*****************************************************************************
+Written and Copyright (C) by Nicolas Kruse
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*****************************************************************************/
+
+#include <avr/io.h>
+#include <util/delay.h>
+#include "nfcemulator.h"
+
+static uint8_t RX_MASK[18] = {0, 1, 0, 2, 0, 4, 0, 8, 0, 16, 0, 32, 0, 64, 0, 128, 0, 0};
+static uint8_t TX_MASK[8] = {1, 2, 4, 8, 16, 32, 64, 128};
+static uint16_t FDT_DELAY[2] = {FDT_DELAY_BIT0, FDT_DELAY_BIT1};
+
+static uint8_t REQA[1] = {0x26};
+static uint8_t WUPA[1] = {0x52};
+static uint8_t HLTA[4] = {0x50,  0x00,  0x57,  0}; //'50' '00' CRC_A
+static uint8_t ATQA[2] = {0x44, 0x00}; //Anticollision with udi size = double
+static uint8_t SEL_CL1[2] =  {0x93, 0x20};
+static uint8_t SEL_CL2[2] =  {0x95, 0x20};
+static uint8_t CT_UID1[5] = {0x88, 0x04, 0xE3, 0xEF, 0}; //uid0 uid1 uid2 uid3 BCC
+static uint8_t UID2[5] = {0xA2, 0xEF, 0x20, 0x80, 0}; //uid3 uid4 uid5 uid6 BCC
+static uint8_t SAK_NC[3] = {0x04, 0xDA, 0x17}; //Select acknowledge uid not complete
+static uint8_t SAK_C[3] = {0x00, 0xFE, 0x51}; //Select acknowledge uid complete, Type 2 (PICC not compliant to ISO/IEC 14443-4)
+static uint8_t READ[1] = {0x30};
+static uint8_t WRITE[1] = {0xA2};
+
+uint8_t *sto; //Pointer to tag content
+uint16_t stoSize; //Number of avalible bytes on the tag
+
+uint8_t buffer[64];
+uint8_t rCount = 0;
+
+void setupNfcEmulator(uint8_t *storage, uint16_t storageSize)
+{
+	//clock divider for 8 bit timer0: clk/1 -> 13.5225 MHz
+	TCCR0B |= (1<<CS00);
+		
+    //8 bit timer0: Toggle OC0A on Compare Match and CTC-Mode
+    //for 847.5 kHz subcarrier
+    TCCR0A |= (1<<COM0A0) | (1<<WGM01);
+		
+	//set up 847.5 kHz subcarrier for sending (8 bit timer0)
+	OCR0A = SUBC_OVF;
+	
+	//CTC-Mode and no clock divider for 16 bit timer1: clk/1
+	TCCR1B = (1<<WGM12) | (1<<CS10);
+	
+	//Setup Analog Comparator, Enable (ACD), Set Analog Comparator
+	//Interrupt Flag on Rising Output Edge (ACIS0, ACIS1)
+	ACSR = (0<<ACD) | (1<<ACIS0) | (1<<ACIS1);
+	
+	addCrc16(HLTA);
+	addBcc(CT_UID1);
+	addBcc(UID2);
+	
+	stoSize = storageSize;
+	sto = storage;
+}
+
+void addCrc16(uint8_t *Data, uint8_t Length)
+{
+	uint8_t ch;
+	uint16_t wCrc = 0x6363; // ITU-V.41
+
+	do {
+		ch = *Data++;
+		
+		ch = (ch^(uint8_t)((wCrc) & 0x00FF));
+		ch = (ch^(ch<<4));
+		wCrc = (wCrc >> 8)^((uint16_t)ch << 8)^((uint16_t)ch<<3)^((uint16_t)ch>>4);
+	} while (--Length);
+
+	*Data = (uint8_t) (wCrc & 0xFF);
+	Data++;
+	*Data = (uint8_t) ((wCrc >> 8) & 0xFF);
+}
+
+
+void addBcc(uint8_t *Data) //add exclusive-OR of 4 bytes
+{
+	Data[4] = Data[0] ^ Data[1] ^ Data[2] ^ Data[3];
+}
+
+void waitForBitend()
+{
+	while(!(TIFR1 & (1<<OCF1A))); //Wait till end of bit-time
+	TIFR1 |= (1<<OCF1A);
+}
+
+#if (F_CPU == RFID_FREQU)
+void waitForOneBitTime()
+{
+	waitForBitend();
+}
+#elif (F_CPU == 22000000UL)
+//Skip every 17 bit times 1 cycle
+void waitForOneBitTime()
+{ 
+	if (rCount < 17)
+	{
+		OCR1AL = CLC_PBIT / 2 - 1;
+		rCount++;
+	}
+	else
+	{
+		OCR1AL = CLC_PBIT / 2 - 2;
+		rCount = 0;
+	}
+	waitForBitend();
+}
+#elif (F_CPU == 13592500UL)
+//Add every 6 bit times 1 cycle
+void waitForOneBitTime()
+{
+	if (rCount < 6)
+	{
+		OCR1AL = CLC_PBIT / 2 - 1;
+		rCount++;
+	}
+	else
+	{
+		OCR1AL = CLC_PBIT / 2;
+		rCount = 0;
+	}
+	waitForBitend();
+}
+#else
+#error "Not supported frequency, please add support if possible"
+#endif
+
+void txManchester(uint8_t *data, uint8_t length)
+{
+	uint8_t txBytePos = 0;
+	uint8_t txbitPos = 0;
+	uint8_t parity = 0;
+	
+	TIFR1 |= (1<<OCF1A);
+	
+	//Send SOC
+	waitForBitend();
+	DDRB |= (1<<2);
+	OCR1A = CLC_PBIT / 2 - 1; //Set Hi- and Low-Bit
+	waitForOneBitTime();
+	DDRB &= ~(1<<2);
+	
+	do
+	{
+		if (TX_MASK[txbitPos] & data[txBytePos])
+		{
+			waitForOneBitTime();
+			DDRB |= (1<<2);
+			parity ^= 1;
+			waitForOneBitTime();
+			DDRB &= ~(1<<2);
+		}
+		else
+		{
+			waitForOneBitTime();
+			DDRB &= ~(1<<2);
+			waitForOneBitTime();
+			DDRB |= (1<<2);
+		}
+		
+		txbitPos++;
+		
+		if (txbitPos > 7)
+		{
+			if (parity)
+			{
+				waitForOneBitTime();
+				DDRB &= ~(1<<2);
+				waitForOneBitTime();
+				DDRB |= (1<<2);
+			}
+			else
+			{
+				waitForOneBitTime();
+				DDRB |= (1<<2);
+				waitForOneBitTime();
+				DDRB &= ~(1<<2);
+			}
+			
+			txBytePos++;
+			txbitPos=0;
+			parity = 0;
+		}
+	}
+	while(txBytePos < length);
+	
+	//Send EOC
+	waitForOneBitTime();
+	DDRB &= ~(1<<2);
+}
+
+inline void resetRxFlags()
+{
+	TCNT1 = 0;
+	TIFR1 |= (1<<OCF1A); //Clear Timer Overflow Flag
+	ACSR |= (1<<ACI); //Clear Analog Comparator Interrupt Flag
+}
+
+uint8_t rxMiller()
+{
+	uint8_t t;
+	uint16_t cDown = 0xFFF;
+	uint8_t bytePos = 0;
+	uint8_t hbitPos = 0;
+	
+	OCR1A = CLCL-1;
+	buffer[0] = 0;
+
+	//Wait for transmission end if there is data arriving
+	do
+	{
+		if (ACSR & (1<<ACI)) resetRxFlags();
+	}
+	while(~TIFR1 & (1<<OCF1A));
+	
+	//Wait for transmission end if there is data arriving
+	do
+	{
+		if (TIFR1 & (1<<OCF1A))
+		{
+			TCNT1 = 0;
+			TIFR1 |= (1<<OCF1A);
+			cDown--;
+			if (!cDown) break;
+		}
+	}
+	while(~ACSR & (1<<ACI));
+	
+	if (cDown)
+	{
+		resetRxFlags();
+		do
+		{
+			if ((ACSR & (1<<ACI)) && (TCNT1 > CMIN))
+			{
+				t = TCNT1;
+				resetRxFlags();
+
+				hbitPos += (t > CLCS) + (t > CLCM);
+
+				if(hbitPos > 17)
+				{
+					bytePos++;
+					hbitPos -= 18;
+					buffer[bytePos] = 0;
+				}
+						
+				buffer[bytePos] |= RX_MASK[hbitPos];
+						
+				hbitPos += 2;
+			} //34 or 41 (hbitPos > 17) click cycles
+		}
+		while(~TIFR1 & (1<<OCF1A));
+	}
+	
+	OCR1A = FDT_DELAY[hbitPos & 1]; //Set delay for answer
+	TIFR1 |= (1<<OCF1A);
+	
+	if (hbitPos > 7) bytePos++;
+
+	return bytePos;
+}
+
+void sendData(uint8_t block)
+{
+	uint8_t i = 0;
+	uint16_t pos = (uint16_t)block * 4;
+	
+	for(i=0; i < 16; i++)
+	{
+		if (pos >= stoSize)
+		{
+			buffer[i] = 0;
+		}			
+		else
+		{
+			buffer[i] = sto[pos];
+		}			
+		
+		pos++;
+	}
+	
+	addCrc16(buffer, 16);
+	txManchester(buffer, 18);
+}
+
+void receiveData(uint8_t block)
+{
+	uint8_t i = 0;
+	uint16_t pos = (uint16_t)block * 4;
+	uint8_t crc1 = buffer[6];
+	uint8_t crc2 = buffer[7];
+	
+	addCrc16(buffer, 6);
+	
+	if (buffer[6] == crc1 && buffer[7] == crc2)
+	{
+		for(i=2; i < 6; i++) //byte 2-5 contains Data
+		{
+			if (pos < stoSize) sto[pos] = buffer[i];
+			pos++;
+		}
+		
+		buffer[0] = 0x0A; //ACK
+		txManchester(buffer, 1);
+	}
+	else
+	{
+		buffer[0] = 0x01; //NAK for CRC error
+		txManchester(buffer, 1);
+	}
+}
+
+void checkForNfcReader()
+{
+	uint8_t bytes = 1;
+	uint8_t state = 0;
+	uint8_t cdow = 8;
+
+	if (ACSR & (1<<ACI)) //13.56 MHz carrier available?
+	{
+		AIN1_PRNG &= ~(1<<AIN1_PORT); //Deactivate pull up to increase sensitivity
+		
+		while(cdow > 0)
+		{
+			bytes = rxMiller();
+
+			if ((state & 7) == S_READY)
+			{
+				if (buffer[0] == SEL_CL1[0] && buffer[1] == SEL_CL1[1] )
+				{
+					txManchester(CT_UID1, sizeof(CT_UID1));
+				}
+				else if (buffer[0] == SEL_CL2[0] && buffer[1] == SEL_CL2[1] )
+				{
+					txManchester(UID2, sizeof(UID2));
+				}
+				else if (buffer[0] == SEL_CL1[0] && buffer[1] == 0x70 )
+				{
+					txManchester(SAK_NC, sizeof(SAK_NC));
+				}
+				else if (buffer[0] == SEL_CL2[0] && buffer[1] == 0x70 )
+				{
+					txManchester(SAK_C, sizeof(SAK_C));
+					state++; //Set state to ACTIVE
+				}
+				else
+				{
+					state &= 8; //Set state to IDLE/HALT
+				}
+			}
+			else if ((state & 7) == S_ACTIVE)
+			{
+				if (buffer[0] == READ[0])
+				{
+					sendData(buffer[1]);
+				}
+				else if (buffer[0] == WRITE[0])
+				{
+					receiveData(buffer[1]);		
+				}
+				else if (buffer[0] == HLTA[0] && buffer[2] == HLTA[2] )
+				{
+					state = S_HALT;
+				}
+				else if(bytes)
+				{
+					state &= 8; //Set state to IDLE/HALT
+				}
+			}
+			else if (bytes == 1 && (buffer[0] == REQA[0] || buffer[0] == WUPA[0])) //state == S_IDLE
+			{
+				txManchester(ATQA, sizeof(ATQA));
+				state = (state & 8) + S_READY; //Set state to READY
+			}	
+			
+			cdow -= (bytes == 0);		
+		}
+		AIN1_PRNG |= (1<<AIN1_PORT); //Activate pull up to prevent noise from toggling the comparator
+	}
+	ACSR |= (1<<ACI); //Clear comparator interrupt flag
+}
\ No newline at end of file