allow for clocks larger than 255 to be used from commandline. added the new command data envelope. it creates square signal, similar to askedgedetect.\n adapted find closest clock in order to make clock /8 less prioritized if there are more found clocks. use second best match in those cases.

common/lfdemod.c

@@ -436,10 +436,10 @@ static size_t findModStart(const uint8_t *src, size_t size, uint8_t expWaveSize)
 }
 
 static int getClosestClock(int testclk) {
-    const uint16_t clocks[] = {8, 16, 32, 40, 50, 64, 100, 128, 256, 384};
-    const uint8_t limit[]  = {1,  2,  4,  4,  5,  8,   8,   8,   8,   8};
+    const uint16_t clocks[] = {8, 16, 32, 40, 50, 64, 100, 128, 256, 272, 384};
+    const uint8_t limit[]  =  {1,  2,  4,  4,  5,  8,   8,   8,   8,   24,   24};
 
-    for (uint8_t i = 0; i < 10; i++) {
+    for (uint8_t i = 0; i < ARRAYLEN(clocks); i++) {
         if (testclk >= clocks[i] - limit[i] && testclk <= clocks[i] + limit[i])
             return clocks[i];
     }
@@ -613,7 +613,7 @@ bool DetectCleanAskWave(const uint8_t *dest, size_t size, uint8_t high, uint8_t
 // based on count of low to low
 int DetectStrongAskClock(uint8_t *dest, size_t size, int high, int low, int *clock) {
     size_t i = 100;
-    size_t minClk = 512;
+    size_t minClk = 768;
     uint16_t shortestWaveIdx = 0;
 
     // get to first full low to prime loop and skip incomplete first pulse
@@ -622,11 +622,11 @@ int DetectStrongAskClock(uint8_t *dest, size_t size, int high, int low, int *clo
 
     if (i == size)
         return -1;
-    if (size < 512)
+    if (size < 768)
         return -2;
 
     // clock, numoftimes, first idx
-    uint16_t tmpclk[10][3] = {
+    uint16_t tmpclk[11][3] = {
         {8,   0, 0},
         {16,  0, 0},
         {32,  0, 0},
@@ -636,11 +636,12 @@ int DetectStrongAskClock(uint8_t *dest, size_t size, int high, int low, int *clo
         {100, 0, 0},
         {128, 0, 0},
         {256, 0, 0},
+        {272, 0, 0},
         {384, 0, 0},
     };
 
     // loop through all samples (well, we don't want to go out-of-bounds)
-    while (i < (size - 512)) {
+    while (i < (size - 768)) {
         // measure from low to low
         size_t startwave = i;
 
@@ -655,7 +656,7 @@ int DetectStrongAskClock(uint8_t *dest, size_t size, int high, int low, int *clo
 
         int foo = getClosestClock(minClk);
         if (foo > 0) {
-            for (uint8_t j = 0; j < 10; j++) {
+            for (uint8_t j = 0; j < 11; j++) {
                 if (tmpclk[j][0] == foo) {
                     tmpclk[j][1]++;
 
@@ -669,8 +670,17 @@ int DetectStrongAskClock(uint8_t *dest, size_t size, int high, int low, int *clo
     }
 
     // find the clock with most hits and it the first index it was encountered.
+    int possible_clks = 0;
+    for (uint8_t j = 0; j < 11; j++) {
+        if (tmpclk[j][1] > 0) {
+            possible_clks++;
+        }
+    }
+
+    uint16_t second_shortest = 0;
+    int second = 0;
     int max = 0;
-    for (uint8_t j = 0; j < 10; j++) {
+    for (int j = 10; j > -1; j--) {
         if (g_debugMode == 2) {
             prnt("DEBUG, ASK,  clocks %u | hits %u | idx %u"
                  , tmpclk[j][0]
@@ -678,13 +688,23 @@ int DetectStrongAskClock(uint8_t *dest, size_t size, int high, int low, int *clo
                  , tmpclk[j][2]
                 );
         }
+
         if (max < tmpclk[j][1]) {
+            second = *clock;
+            second_shortest = shortestWaveIdx;
+
             *clock = tmpclk[j][0];
             shortestWaveIdx = tmpclk[j][2];
             max = tmpclk[j][1];
         }
     }
 
+    // ASK clock 8 is very rare and usually gives us false positives
+    if (possible_clks > 1 && *clock == 8) {
+        *clock = second;
+        shortestWaveIdx = second_shortest;
+    }
+
     if (*clock == 0)
         return -1;
 
@@ -712,9 +732,9 @@ int DetectASKClock(uint8_t *dest, size_t size, int *clock, int maxErr) {
     }
 
     size_t i = 1;
-    uint8_t num_clks = 9;
+    uint8_t num_clks = 10;
     // first 255 value pos0 is placeholder for user inputed clock.
-    uint16_t clk[] = {255, 8, 16, 32, 40, 50, 64, 100, 128, 255};
+    uint16_t clk[] = {255, 8, 16, 32, 40, 50, 64, 100, 128, 255, 272};
 
     // sometimes there is a strange end wave - filter out this
     size -= 60;
@@ -755,8 +775,8 @@ int DetectASKClock(uint8_t *dest, size_t size, int *clock, int maxErr) {
 
     uint8_t clkCnt, tol;
     size_t j = 0;
-    uint16_t bestErr[] = {1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000};
-    uint8_t bestStart[] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
+    uint16_t bestErr[] = {1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000};
+    uint8_t bestStart[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
     size_t errCnt, arrLoc, loopEnd;
 
     if (found_clk) {