-int CmdFSKdemod(const char *Cmd) //old CmdFSKdemod needs updating
-{
- static const int LowTone[] = {
- 1, 1, 1, 1, 1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, -1, -1, -1, -1, -1
- };
- static const int HighTone[] = {
- 1, 1, 1, 1, 1, -1, -1, -1, -1,
- 1, 1, 1, 1, -1, -1, -1, -1,
- 1, 1, 1, 1, -1, -1, -1, -1,
- 1, 1, 1, 1, -1, -1, -1, -1,
- 1, 1, 1, 1, -1, -1, -1, -1,
- 1, 1, 1, 1, -1, -1, -1, -1, -1,
- };
-
- int lowLen = sizeof (LowTone) / sizeof (int);
- int highLen = sizeof (HighTone) / sizeof (int);
- int convLen = (highLen > lowLen) ? highLen : lowLen;
- uint32_t hi = 0, lo = 0;
-
- int i, j;
- int minMark = 0, maxMark = 0;
-
- for (i = 0; i < GraphTraceLen - convLen; ++i) {
- int lowSum = 0, highSum = 0;
-
- for (j = 0; j < lowLen; ++j) {
- lowSum += LowTone[j]*GraphBuffer[i+j];
- }
- for (j = 0; j < highLen; ++j) {
- highSum += HighTone[j] * GraphBuffer[i + j];
- }
- lowSum = abs(100 * lowSum / lowLen);
- highSum = abs(100 * highSum / highLen);
- GraphBuffer[i] = (highSum << 16) | lowSum;
- }
-
- for(i = 0; i < GraphTraceLen - convLen - 16; ++i) {
- int lowTot = 0, highTot = 0;
- // 10 and 8 are f_s divided by f_l and f_h, rounded
- for (j = 0; j < 10; ++j) {
- lowTot += (GraphBuffer[i+j] & 0xffff);
- }
- for (j = 0; j < 8; j++) {
- highTot += (GraphBuffer[i + j] >> 16);
- }
- GraphBuffer[i] = lowTot - highTot;
- if (GraphBuffer[i] > maxMark) maxMark = GraphBuffer[i];
- if (GraphBuffer[i] < minMark) minMark = GraphBuffer[i];
- }
-
- GraphTraceLen -= (convLen + 16);
- RepaintGraphWindow();
-
- // Find bit-sync (3 lo followed by 3 high) (HID ONLY)
- int max = 0, maxPos = 0;
- for (i = 0; i < 6000; ++i) {
- int dec = 0;
- for (j = 0; j < 3 * lowLen; ++j) {
- dec -= GraphBuffer[i + j];
- }
- for (; j < 3 * (lowLen + highLen ); ++j) {
- dec += GraphBuffer[i + j];
- }
- if (dec > max) {
- max = dec;
- maxPos = i;
- }
- }
-
- // place start of bit sync marker in graph
- GraphBuffer[maxPos] = maxMark;
- GraphBuffer[maxPos + 1] = minMark;
-
- maxPos += j;
-
- // place end of bit sync marker in graph
- GraphBuffer[maxPos] = maxMark;
- GraphBuffer[maxPos+1] = minMark;
-
- PrintAndLog("actual data bits start at sample %d", maxPos);
- PrintAndLog("length %d/%d", highLen, lowLen);
-
- uint8_t bits[46] = {0x00};
-
- // find bit pairs and manchester decode them
- for (i = 0; i < arraylen(bits) - 1; ++i) {
- int dec = 0;
- for (j = 0; j < lowLen; ++j) {
- dec -= GraphBuffer[maxPos + j];
- }
- for (; j < lowLen + highLen; ++j) {
- dec += GraphBuffer[maxPos + j];
- }
- maxPos += j;
- // place inter bit marker in graph
- GraphBuffer[maxPos] = maxMark;
- GraphBuffer[maxPos + 1] = minMark;
-
- // hi and lo form a 64 bit pair
- hi = (hi << 1) | (lo >> 31);
- lo = (lo << 1);
- // store decoded bit as binary (in hi/lo) and text (in bits[])
- if(dec < 0) {
- bits[i] = '1';
- lo |= 1;
- } else {
- bits[i] = '0';
- }
- }
- PrintAndLog("bits: '%s'", bits);
- PrintAndLog("hex: %08x %08x", hi, lo);
- return 0;
-}
-
projects / proxmark3-svn / commitdiff