diff --git a/W433DataTransmitter.cpp b/W433DataTransmitter.cpp
index 62906b4..9221c06 100644
--- a/W433DataTransmitter.cpp
+++ b/W433DataTransmitter.cpp
@@ -1,93 +1,64 @@
 #include "W433DataTransmitter.h"
 #include "writepin.h"
+#include <util/crc16.h>
 
 W433DataTransmitter::W433DataTransmitter(volatile unsigned char *port, const unsigned char pin): _port(port), _pin(pin)
 {
 }
 
-void W433DataTransmitter::sendBit(const bool bit) 
-{ 
-    switch(bit)
-    {
-        case true:
-		writePin(_port,_pin,true);
-        _delay_us(SMALL_TIME);
-        writePin(_port,_pin,false);
-        _delay_us(LARGE_TIME);
-        writePin(_port,_pin,true);
-        _delay_us(SMALL_TIME);
-        writePin(_port,_pin,false);
-        _delay_us(LARGE_TIME);
-        break;
-
-        case false:
-        writePin(_port,_pin,true);
-        _delay_us(LARGE_TIME);
-        writePin(_port,_pin,false);
-        _delay_us(SMALL_TIME);
-        writePin(_port,_pin,true);
-        _delay_us(SMALL_TIME);
-        writePin(_port,_pin,false);
-        _delay_us(LARGE_TIME);
-        break;
-    }   
+uint16_t W433DataTransmitter::calcCrc(const uint32_t data)
+{
+    uint16_t crc = 0xffff;
+    const uint8_t* ptr = reinterpret_cast<const uint8_t*>(&data);
+    for(uint8_t i = 0; i < sizeof(data); ++i)
+        crc = _crc_ccitt_update(crc, ptr[i]);
+    return crc;
 }
 
-void W433DataTransmitter::sendSyncpulse()
+void W433DataTransmitter::sendSymbol(const uint8_t data)
 {
-    for(uint8_t i = 0; i < 25; ++i)
-    {
-        writePin(_port,_pin,true);
-        _delay_us(SYNC_TIME);
-        writePin(_port,_pin,false);
-        _delay_us(SYNC_TIME);
-    }
+	for(uint8_t i = 0; i < 6; ++i)
+	{
+		writePin(_port, _pin, data & 1<<i);
+		_delay_us(DELAY_US);
+	}
 }
 
-void W433DataTransmitter::sendEndPulse()
+void W433DataTransmitter::sendData(const uint8_t data)
 {
-    writePin(_port,_pin,false);
-    _delay_us(LARGE_TIME);
-    writePin(_port,_pin,true);
-    _delay_us(LARGE_TIME);
-    writePin(_port,_pin,false);
-    _delay_us(LARGE_TIME*10);
-}
-
-void W433DataTransmitter::sendRawData(const uint8_t data)
-{
-    for(uint8_t i = 0; i < 8; i++) sendBit(data & ( 1 << (7 - i)));
+	sendSymbol(symbols[data & 0x0F]);
+	sendSymbol(symbols[data >> 4]);
 }
 
 void W433DataTransmitter::sendPacket(const uint32_t data)
 {
-    sendSyncpulse();
-    _delay_us(LARGE_TIME);
-    sendRawData(signature);
-    uint8_t checksum = 0;
-    for(uint8_t i = 0; i < 4; ++i)
-    {
-        uint8_t dataOctet = (data & (0xFF000000 >> i*8 )) >> (24 - 8*i);
-        //for(uint8_t i = 0; i < 8; i++) checksum = checksum + (dataOctet & ( 1 << (8 - i)));
-        for(uint8_t i = 0; i < 8; i++) checksum = checksum + ((dataOctet & ( 1 << (8 - i))) >> (8 - i));
-        sendRawData( dataOctet );
-        
-    }
-    sendRawData( checksum );
-    sendEndPulse();
+	_delay_ms(LONG_DELAY_MS);
+	sendSymbol(SIGNATURE & 0b111111);
+	sendSymbol(SIGNATURE >> 6);
+	for(uint8_t i = 0; i < 4; ++i)
+	{
+		uint8_t dataOctet = (data & (0xFF000000 >> i*8 )) >> (24 - 8*i);
+		sendData(dataOctet);
+	}
+	uint16_t crc = calcCrc(data);
+	sendData(crc & 0xFF);
+	sendData(crc >> 8);
 }
 
 void W433DataTransmitter::send(const uint8_t* const data, uint16_t length)
 {
 	uint16_t packets = length/4;
-	if(length % 4 != 0) ++packets;
-    for(uint8_t j = 0; j < packets; j++)
-    {
-        uint32_t paketData = 0;
-        uint8_t* paketDataPointer = reinterpret_cast<uint8_t*>(&paketData);
-        for(uint8_t i = 0; i < 4 && j*4+i < length; i++) paketDataPointer[3-i] = data[j*4+i];
-        sendPacket(paketData);
-    }
+	if(length % 4 != 0)
+		++packets;
+	for(uint8_t j = 0; j < packets; j++)
+	{
+		uint32_t paketData = 0;
+		uint8_t* paketDataPointer = reinterpret_cast<uint8_t*>(&paketData);
+		for(uint8_t i = 0; i < 4 && static_cast<uint16_t>(j*4+i) < length; i++)
+			paketDataPointer[3-i] = data[j*4+i];
+		sendPacket(paketData);
+	}
+
 }
 
 void W433DataTransmitter::send(const uint8_t data)
diff --git a/W433DataTransmitter.h b/W433DataTransmitter.h
index 007f8a2..f1d131d 100644
--- a/W433DataTransmitter.h
+++ b/W433DataTransmitter.h
@@ -7,24 +7,29 @@
 class W433DataTransmitter
 {
 private:
-    
-    static constexpr uint16_t LARGE_TIME = 2000;
-    static constexpr uint16_t SMALL_TIME = 500;
-    static constexpr uint16_t SYNC_TIME = 800;
-    
-    static constexpr uint8_t signature = 0xA5;
-    volatile unsigned char * const _port;
-    const unsigned char _pin;
-    
-    void sendBit(const bool bit);
-    void sendSyncpulse();
-    void sendRawData(const uint8_t data);
-    void sendEndPulse();
+	static constexpr uint16_t BIT_RATE = 2000;
+	static constexpr int32_t DELAY_US = 1000000/BIT_RATE;
+	static constexpr int16_t LONG_DELAY_MS = 10;
+	static constexpr uint16_t SIGNATURE = 0xb38;
+	volatile unsigned char * const _port;
+	const unsigned char _pin;
+
+	void sendSymbol(const uint8_t data);
+	void sendData(const uint8_t data);
+
+	static constexpr int SYMBOL_TABLE_SIZE = 16;
+	static constexpr uint8_t symbols[SYMBOL_TABLE_SIZE] =
+	{
+		0xd,  0xe,  0x13, 0x15, 0x16, 0x19, 0x1a, 0x1c,
+		0x23, 0x25, 0x26, 0x29, 0x2a, 0x2c, 0x32, 0x34
+	};
+
+	uint16_t calcCrc(const uint32_t data);
     
 public:
     
-    W433DataTransmitter(volatile unsigned char * const port, const unsigned char pin);
-    void send(const uint8_t* const data, uint16_t length);
-    void send(const uint8_t data);
-    void sendPacket(const uint32_t data);
+	W433DataTransmitter(volatile unsigned char * const port, const unsigned char pin);
+	void send(const uint8_t* const data, uint16_t length);
+	void send(const uint8_t data);
+	void sendPacket(const uint32_t data);
 };