removed redundant function to compose reader short frame

armsrc/hitag2.c

@@ -29,10 +29,6 @@ bool bAuthenticating;
 bool bPwd;
 bool bSuccessful;
 
-size_t nbytes(size_t nbits) {
-	return (nbits/8)+((nbits%8)>0);
-}
-
 int LogTraceHitag(const uint8_t * btBytes, int iBits, int iSamples, uint32_t dwParity, int bReader)
 {
   // Return when trace is full

armsrc/iso14443a.c

@@ -1262,12 +1262,11 @@ static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wa
 }
 
 //-----------------------------------------------------------------------------
-// Code a 7-bit command without parity bit
+// Prepare reader command (in bits, support short frames) to send to FPGA
-// This is especially for 0x26 and 0x52 (REQA and WUPA)
 //-----------------------------------------------------------------------------
-void ShortFrameFromReader(const uint8_t bt)
+void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
 {
-	int j;
+  int i, j;
   int last;
   uint8_t b;
 
@@ -1277,18 +1276,23 @@ void ShortFrameFromReader(const uint8_t bt)
   ToSend[++ToSendMax] = SEC_Z;
   last = 0;
 
-	b = bt;
+  size_t bytecount = nbytes(bits);
-	for(j = 0; j < 7; j++) {
+  // Generate send structure for the data bits
-		if(b & 1) {
+  for (i = 0; i < bytecount; i++) {
+    // Get the current byte to send
+    b = cmd[i];
+    size_t bitsleft = MIN((bits-(i*8)),8);
+
+    for (j = 0; j < bitsleft; j++) {
+      if (b & 1) {
         // Sequence X
     	  ToSend[++ToSendMax] = SEC_X;
         last = 1;
       } else {
-			if(last == 0) {
+        if (last == 0) {
           // Sequence Z
         	ToSend[++ToSendMax] = SEC_Z;
-			}
+        } else {
-			else {
           // Sequence Y
         	ToSend[++ToSendMax] = SEC_Y;
           last = 0;
@@ -1297,12 +1301,31 @@ void ShortFrameFromReader(const uint8_t bt)
       b >>= 1;
     }
 
-	// End of Communication
+    // Only transmit (last) parity bit if we transmitted a complete byte
-	if(last == 0) {
+    if (j == 8) {
+      // Get the parity bit
+      if ((dwParity >> i) & 0x01) {
+        // Sequence X
+        ToSend[++ToSendMax] = SEC_X;
+        last = 1;
+      } else {
+        if (last == 0) {
           // Sequence Z
           ToSend[++ToSendMax] = SEC_Z;
+        } else {
+          // Sequence Y
+          ToSend[++ToSendMax] = SEC_Y;
+          last = 0;
         }
-	else {
+      }
+    }
+  }
+
+  // End of Communication
+  if (last == 0) {
+    // Sequence Z
+	  ToSend[++ToSendMax] = SEC_Z;
+  } else {
     // Sequence Y
 	  ToSend[++ToSendMax] = SEC_Y;
     last = 0;
@@ -1321,79 +1344,10 @@ void ShortFrameFromReader(const uint8_t bt)
 
 //-----------------------------------------------------------------------------
 // Prepare reader command to send to FPGA
-//
 //-----------------------------------------------------------------------------
 void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
 {
-  int i, j;
+  CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
-  int last;
-  uint8_t b;
-
-  ToSendReset();
-
-  // Start of Communication (Seq. Z)
-  ToSend[++ToSendMax] = SEC_Z;
-  last = 0;
-
-  // Generate send structure for the data bits
-  for (i = 0; i < len; i++) {
-    // Get the current byte to send
-    b = cmd[i];
-
-    for (j = 0; j < 8; j++) {
-      if (b & 1) {
-        // Sequence X
-    	  ToSend[++ToSendMax] = SEC_X;
-        last = 1;
-      } else {
-        if (last == 0) {
-          // Sequence Z
-        	ToSend[++ToSendMax] = SEC_Z;
-        } else {
-          // Sequence Y
-        	ToSend[++ToSendMax] = SEC_Y;
-          last = 0;
-        }
-      }
-      b >>= 1;
-    }
-
-    // Get the parity bit
-    if ((dwParity >> i) & 0x01) {
-      // Sequence X
-    	ToSend[++ToSendMax] = SEC_X;
-      last = 1;
-    } else {
-      if (last == 0) {
-        // Sequence Z
-    	  ToSend[++ToSendMax] = SEC_Z;
-      } else {
-        // Sequence Y
-    	  ToSend[++ToSendMax] = SEC_Y;
-        last = 0;
-      }
-    }
-  }
-
-  // End of Communication
-  if (last == 0) {
-    // Sequence Z
-	  ToSend[++ToSendMax] = SEC_Z;
-  } else {
-    // Sequence Y
-	  ToSend[++ToSendMax] = SEC_Y;
-    last = 0;
-  }
-  // Sequence Y
-  ToSend[++ToSendMax] = SEC_Y;
-
-  // Just to be sure!
-  ToSend[++ToSendMax] = SEC_Y;
-  ToSend[++ToSendMax] = SEC_Y;
-  ToSend[++ToSendMax] = SEC_Y;
-
-  // Convert from last character reference to length
-  ToSendMax++;
 }
 
 //-----------------------------------------------------------------------------
@@ -1598,7 +1552,8 @@ void ReaderTransmitShort(const uint8_t* bt)
   int wait = 0;
   int samples = 0;
 
-  ShortFrameFromReader(*bt);
+//  ShortFrameFromReader(*bt);
+  CodeIso14443aBitsAsReaderPar(bt,7,0);
 
   // Select the card
   TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);

armsrc/util.c

@@ -12,6 +12,10 @@
 #include "util.h"
 #include "string.h"
 
+size_t nbytes(size_t nbits) {
+	return (nbits/8)+((nbits%8)>0);
+}
+
 uint32_t SwapBits(uint32_t value, int nrbits) {
 	int i;
 	uint32_t newvalue = 0;

armsrc/util.h

@@ -27,6 +27,7 @@
 #define BUTTON_DOUBLE_CLICK -2
 #define BUTTON_ERROR -99
 
+size_t nbytes(size_t nbits);
 uint32_t SwapBits(uint32_t value, int nrbits);
 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest);
 uint64_t bytes_to_num(uint8_t* src, size_t len);