diff --git a/arduino/ArduinoTellstickDuo/archtech.cpp b/arduino/ArduinoTellstickDuo/archtech.cpp
index a6a382bf..74662a3b 100644
--- a/arduino/ArduinoTellstickDuo/archtech.cpp
+++ b/arduino/ArduinoTellstickDuo/archtech.cpp
@@ -23,8 +23,8 @@ Total: 32 or 36 bits depending if absolute dimming is used
 
 Each real bit in the data field is sent over air as a pair of two inverted bits.
   real bit        bits over air
-     1       =        "01"
-     0       =        "10"
+     1       =        "10"
+     0       =        "01"
 
 Over air a "1"(one) is sent as:
 send high for 250 microseconds
@@ -44,61 +44,66 @@ send low for 10,000 microseconds
 #define ARCHTECH_SHORT_MAX       7
 #define ARCHTECH_LONG_MIN       17
 #define ARCHTECH_LONG_MAX       27
+#define ARCHTECH_PREAMP_MIN     40
+#define ARCHTECH_PREAMP_MAX     48
 
-#define IS_SHORT(b) ( ARCHTECH_SHORT_MIN <= b && b <= ARCHTECH_SHORT_MAX )
-#define IS_LONG(b)  (  ARCHTECH_LONG_MIN <= b && b <= ARCHTECH_LONG_MAX  )
+#define IS_SHORT(b)         (  ARCHTECH_SHORT_MIN <= b && b <= ARCHTECH_SHORT_MAX )
+#define IS_LONG(b)          (   ARCHTECH_LONG_MIN <= b && b <= ARCHTECH_LONG_MAX  )
+#define IS_PREAMP_LONG(b)   ( ARCHTECH_PREAMP_MIN <= b && b <= ARCHTECH_PREAMP_MAX )
 
-#define IS_ZERO(b1,b2,b3,b4) ( IS_SHORT(b1) && IS_LONG(b2)  && IS_SHORT(b3) && IS_SHORT(b4) )
-#define IS_ONE(b1,b2,b3,b4)  ( IS_SHORT(b1) && IS_SHORT(b2) && IS_SHORT(b3) && IS_LONG(b4)  )
+#define IS_ONE(b1,b2,b3,b4)   ( IS_SHORT(b1) && IS_LONG(b2)  && IS_SHORT(b3) && IS_SHORT(b4) )
+#define IS_ZERO(b1,b2,b3,b4)  ( IS_SHORT(b1) && IS_SHORT(b2) && IS_SHORT(b3) && IS_LONG(b4)  )
+#define IS_PREAMP(b1,b2)      ( IS_SHORT(b1) && IS_PREAMP_LONG(b2) )
 
 bool parseArctechSelfLearning(uint8_t* bufStartP, uint8_t* bufEndP) {    //start points to a "high" buffer byte, end points to a "low" buffer byte
   uint64_t data = 0;
   bool dimValuePresent;
+  uint8_t b1,b2,b3,b4;
+  
+  //parse preamp
 
-  uint16_t bitsInBuffer = calculateBufferPointerDistance(bufStartP, bufEndP) / 4;   //each bit is representd by 4 high/low
-  //Serial.print("bits in buffer: "); Serial.print(bitsInBuffer); Serial.print(" - ");
-  if (bitsInBuffer == 33) {
-    //Serial.println("default");
-    dimValuePresent = false;
-  }else if(bitsInBuffer == 37){
-    //Serial.println("with dim");
-    dimValuePresent = true;
-  } else {
-    //Serial.println("ignore");
+  b1 = *bufStartP;
+  stepBufferPointer(&bufStartP);
+  b2 = *bufStartP;
+  stepBufferPointer(&bufStartP);
+  if(!IS_PREAMP(b1, b2)){
     return false;
   }
 
-  //stkip two buffers entries. 
-  stepBufferPointer(&bufStartP);
-  stepBufferPointer(&bufStartP);
+  //parse data
   
-  for (uint8_t i = 0; i < bitsInBuffer-1; ++i) {
-
-    uint8_t b1 = *bufStartP;    //no of high
+  uint16_t dataBitsInBuffer = (calculateBufferPointerDistance(bufStartP, bufEndP)-2) / 4;   //each bit is representd by 4 high/low
+  if (dataBitsInBuffer == 32) {
+    dimValuePresent = false;
+  }else if(dataBitsInBuffer == 36){
+    dimValuePresent = true;
+  } else {
+    return false;
+  }
+  
+  for (uint8_t i = 0; i < dataBitsInBuffer; ++i) {
+    b1 = *bufStartP;    //no of high
     stepBufferPointer(&bufStartP);
-    uint8_t b2 = *bufStartP;    //no of low
+    b2 = *bufStartP;    //no of low
     stepBufferPointer(&bufStartP);
-    uint8_t b3 = *bufStartP;    //no of high
+    b3 = *bufStartP;    //no of high
     stepBufferPointer(&bufStartP);
-    uint8_t b4 = *bufStartP;    //no of low
+    b4 = *bufStartP;    //no of low
     stepBufferPointer(&bufStartP);
 
-    //Serial.print(b1); Serial.print(", ");Serial.print(b2); Serial.print(", ");Serial.print(b3); Serial.print(", ");Serial.print(b4);
-
     if (IS_ONE(b1,b2,b3,b4)) {  //"one" is sent over air
-      //Serial.println(" --> 1");
       data <<= 1; //shift in a zero
       data |= 0x1;    //add one
     } else if (IS_ZERO(b1,b2,b3,b4)) { //"zero" is sent over air
-      //Serial.println(" --> 0");
       data <<= 1; //shift in a zero
     } else {
-      //Serial.println(" --> CORRUPT");
       return false;
     }
 
   }
 
+  //data parsed - send event over serial
+  
   Serial.print(F("+Wclass:command;protocol:arctech;model:selflearning;data:0x"));
   uint8_t hexToSend = (dimValuePresent ? 9 : 8);
   for (int8_t i = hexToSend - 1; i >= 0; --i) {