add first attempt at lf miller decoding

don't have any tags capable to test and not yet hooked up to data
rawdemod...

diff --git a/client/cmddata.c b/client/cmddata.c
index e07e72235a8c624d22880372e67c8468bb20bd92..f1e6c7958765cd933c15ffec6b0d93a83a514e2c 100644 (file)
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -29,6 +29,9 @@
 uint8_t DemodBuffer[MAX_DEMOD_BUF_LEN];
 uint8_t g_debugMode=0;
 size_t DemodBufferLen=0;
+size_t g_demodStartIdx=0;
+uint8_t g_demodClock=0;
+
 static int CmdHelp(const char *Cmd);
 
 //set the demod buffer with given array of binary (one bit per byte)
@@ -253,6 +256,7 @@ void printEM410x(uint32_t hi, uint64_t id)
        return;
 }
 
+//should be moved to cmdlfem4x.c
 int AskEm410xDecode(bool verbose, uint32_t *hi, uint64_t *lo )
 {
        size_t idx = 0;
@@ -274,7 +278,7 @@ int AskEm410xDecode(bool verbose, uint32_t *hi, uint64_t *lo )
        }
        return 0;
 }
-
+//should be moved to cmdlfem4x.c
 int AskEm410xDemod(const char *Cmd, uint32_t *hi, uint64_t *lo, bool verbose)
 {
        bool st = true;
@@ -282,6 +286,7 @@ int AskEm410xDemod(const char *Cmd, uint32_t *hi, uint64_t *lo, bool verbose)
        return AskEm410xDecode(verbose, hi, lo);
 }
 
+//should be moved to cmdlfem4x.c
 //by marshmellow
 //takes 3 arguments - clock, invert and maxErr as integers
 //attempts to demodulate ask while decoding manchester
@@ -451,7 +456,8 @@ int Cmdmandecoderaw(const char *Cmd)
 
        sscanf(Cmd, "%i %i", &invert, &maxErr);
        size=i;
-       errCnt=manrawdecode(BitStream, &size, invert);
+       uint8_t alignPos = 0;
+       errCnt=manrawdecode(BitStream, &size, invert, &alignPos);
        if (errCnt>=maxErr){
                PrintAndLog("Too many errors: %d",errCnt);
                return 0;
@@ -590,6 +596,7 @@ int Cmdaskbiphdemod(const char *Cmd)
        return ASKbiphaseDemod(Cmd, true);
 }
 
+//could be split to a gProxII file
 //by marshmellow
 //attempts to demodulate and identify a G_Prox_II verex/chubb card
 //WARNING: if it fails during some points it will destroy the DemodBuffer data
@@ -655,6 +662,7 @@ int CmdG_Prox_II_Demod(const char *Cmd)
        return 1;
 }
 
+//could be moved to a viking file
 //by marshmellow
 //see ASKDemod for what args are accepted
 int CmdVikingDemod(const char *Cmd)
@@ -1038,6 +1046,7 @@ int CmdFSKrawdemod(const char *Cmd)
        return FSKrawDemod(Cmd, true);
 }
 
+//move to cmdlfhid.c
 //by marshmellow (based on existing demod + holiman's refactor)
 //HID Prox demod - FSK RF/50 with preamble of 00011101 (then manchester encoded)
 //print full HID Prox ID and some bit format details if found
@@ -1124,6 +1133,7 @@ int CmdFSKdemodHID(const char *Cmd)
        return 1;
 }
 
+
 //by marshmellow
 //Paradox Prox demod - FSK RF/50 with preamble of 00001111 (then manchester encoded)
 //print full Paradox Prox ID and some bit format details if found
@@ -2264,13 +2274,13 @@ int CmdDirectionalThreshold(const char *Cmd)
                if (GraphBuffer[i] >= upThres && GraphBuffer[i] > lastValue)
                {
                        lastValue = GraphBuffer[i]; // Buffer last value as we overwrite it.
-                       GraphBuffer[i] = 1;
+                       GraphBuffer[i] = 127;
                }
                // Apply second threshold to samples heading down
                else if (GraphBuffer[i] <= downThres && GraphBuffer[i] < lastValue)
                {
                        lastValue = GraphBuffer[i]; // Buffer last value as we overwrite it.
-                       GraphBuffer[i] = -1;
+                       GraphBuffer[i] = -127;
                }
                else
                {

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 750dbf1b43a17bd1d2c011abde63f752748fff0e..fb10f6864d81b813bef66cd79b61e9d5d9ac7ac2 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -1074,17 +1074,18 @@ bool DetectST(uint8_t   buffer[], size_t *size, int *foundclock) {
 }
 
 //by marshmellow
-//take 11 10 01 11 00 and make 01100 ... miller decoding
+//take 11 10 01 11 00 and make 01100 ... miller decoding 
 //check for phase errors - should never have half a 1 or 0 by itself and should never exceed 1111 or 0000 in a row
 //decodes miller encoded binary
 //NOTE  askrawdemod will NOT demod miller encoded ask unless the clock is manually set to 1/2 what it is detected as!
-/*int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) {
+int millerRawDecode(uint8_t *BitStream, size_t *size, int invert) {
        if (*size < 16) return -1;
-       uint16_t MaxBits = 512, errCnt = 0, bestErr = 1000, bestRun = 0;
-       size_t i, ii, bitCnt=0;
-       uint8_t alignCnt = 0, curBit = BitStream[0];
+       uint16_t MaxBits = 512, errCnt = 0;
+       size_t i, bitCnt=0;
+       uint8_t alignCnt = 0, curBit = BitStream[0], alignedIdx = 0;
+       uint8_t halfClkErr = 0;
        //find alignment, needs 4 1s or 0s to properly align
-       for (i=1; i < *size; i++) {
+       for (i=1; i < *size-1; i++) {
                alignCnt = (BitStream[i] == curBit) ? alignCnt+1 : 0;
                curBit = BitStream[i];
                if (alignCnt == 4) break;
@@ -1094,8 +1095,21 @@ bool DetectST(uint8_t    buffer[], size_t *size, int *foundclock) {
                if (g_debugMode) prnt("ERROR MillerDecode: alignment not found so either your bitstream is not miller or your data does not have a 101 in it");
                return -1;
        }
+       alignedIdx = (i-1) % 2;
+       for (i=alignedIdx; i < *size-3; i+=2) {
+               halfClkErr = (uint8_t)((halfClkErr << 1 | BitStream[i]) & 0xFF);
+               if ( (halfClkErr & 0x7) == 5 || (halfClkErr & 0x7) == 2 || (i > 2 && (halfClkErr & 0x7) == 0) || (halfClkErr & 0x1F) == 0x1F) {
+                       errCnt++;
+                       BitStream[bitCnt++] = 7;
+                       continue;
+               }
+               BitStream[bitCnt++] = BitStream[i] ^ BitStream[i+1] ^ invert;
 
-}*/
+               if (bitCnt > MaxBits) break;
+       }
+       *size = bitCnt;
+       return errCnt;
+}
 
 //by marshmellow
 //take 01 or 10 = 1 and 11 or 00 = 0
@@ -1876,7 +1890,6 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) {
        return (int) startIdx;
 }
 
-
 // by iceman
 // find Visa2000 preamble in already demoded data
 int Visa2kDemod_AM(uint8_t *dest, size_t *size) {