Calculate AM modulation depth and improved pass band calculation

plot.c

@@ -519,6 +519,13 @@ draw_on_strut(int v0, int d, int color)
  * calculate log10f(abs(gamma))
  */ 
 
+
+float
+index_to_value(const int i)
+{
+  return(value(actual_t[i]));
+}
+
 float
 value(const float v)
 {
@@ -2084,31 +2091,47 @@ static void cell_draw_marker_info(int x0, int y0)
   if (setting.measurement == M_THD && active >= 1)
     active = 2;
   for (int i = 0; i < MARKER_COUNT; i++) {
-    if (i == 3 && setting.measurement == M_PASS_BAND) {
+    if (i == 3) {
+      if (setting.measurement == M_PASS_BAND) {
         uint32_t f;
         if (markers[2].frequency>markers[1].frequency)
           f = markers[2].frequency-markers[1].frequency;
         else
           f = markers[1].frequency-markers[2].frequency;
         plot_printf(buf, sizeof buf, "WIDTH: %8.3qHz", f);
+    show_computed:
         j = 3;
         int xpos = 1 + (j%2)*(WIDTH/2) + CELLOFFSETX - x0;
         int ypos = 1 + (j/2)*(16) - y0;
         cell_drawstring_7x13(buf, xpos, ypos);
         //        cell_drawstring(buf, xpos, ypos);
+      } else if (setting.measurement == M_AM){
+#ifdef AM_IN_VOLT
+        int old_unit = setting.unit;
+        setting.unit = U_VOLT;
+        float level = (index_to_value(markers[1].index) + index_to_value(markers[2].index))/2 / index_to_value(markers[0].index);
+        setting.unit = old_unit;
+        int depth = (int)( level * 2.0 * 80.0) + 20;
+#else
+        float level = actual_t[markers[0].index] - (actual_t[markers[1].index] + actual_t[markers[2].index])/2.0 ;
+        int depth = (int)( (15.0 - level) / 9.0 * 50) + 50;
+#endif
+        plot_printf(buf, sizeof buf, "DEPTH: %3d%%", depth);
+        goto show_computed;
         break;
-    } else
+      }
+    }
     if (i >= 2 && setting.measurement == M_THD) {
       if (i == 2 && (markers[0].index << 5) > sweep_points ) {
         int old_unit = setting.unit;
         setting.unit = U_WATT;
-        float p = value((actual_t[markers[0].index]));
+        float p = index_to_value(markers[0].index);
         int j = 2;
         uint32_t f = markers[0].frequency;
         float h = 0.0;
         while (f * j < frequencies[sweep_points-1]) {
           if (search_maximum(1, f*j, 4*j) )             // use marker 1 for searching harmonics
-            h += value((actual_t[markers[1].index]));
+            h += index_to_value(markers[1].index);
           j++;
         }
         float thd = 100.0 * sqrt(h/p);
@@ -2125,10 +2148,10 @@ static void cell_draw_marker_info(int x0, int y0)
       break;
     } else
     if (i >= 2 && setting.measurement == M_OIP3 && markers[2].enabled && markers[3].enabled) {
-      float il = value((actual_t[markers[2].index]));
+      float il = index_to_value(markers[2].index);
-      float ir = value((actual_t[markers[3].index]));
+      float ir = index_to_value(markers[3].index);
-      float sl = value((actual_t[markers[0].index]));
+      float sl = index_to_value(markers[0].index);
-      float sr = value((actual_t[markers[1].index]));
+      float sr = index_to_value(markers[1].index);
 
       float ip = sl+ (sr - il)/2;
       plot_printf(buf, sizeof buf, "OIP3: %4.1fdB", ip);

sa_core.c

@@ -2374,18 +2374,18 @@ sweep_again:                                // stay in sweep loop when output mo
       if (markers[2].index < 0) markers[1].index = setting._sweep_points - 1;
       markers[2].frequency = frequencies[markers[2].index];
     } else if (setting.measurement == M_PASS_BAND  && markers[0].index > 10) {      // ----------------Pass band measurement
-      int t = markers[0].index;
+      int t = 0;
-      float v = actual_t[t];
+      float v = actual_t[markers[0].index] - 3.0;
-      while (t > 0 && actual_t[t] > v - 4.0)                                        // Find left -3dB point
+      while (t < markers[0].index && actual_t[t+1] < v)                                        // Find left -3dB point
-        t --;
+        t++;
-      if (t > 0) {
+      if (t< markers[0].index) {
         markers[1].index = t;
         markers[1].frequency = frequencies[t];
       }
-      t = markers[0].index;
+      t = setting._sweep_points-1;;
-      while (t < setting._sweep_points - 1 && actual_t[t] > v - 4.0)                // find right -3dB point
+      while (t > markers[0].index && actual_t[t-1] < v)                // find right -3dB point
-        t ++;
+        t--;
-      if (t < setting._sweep_points - 1 ) {
+      if (t > markers[0].index) {
         markers[2].index = t;
         markers[2].frequency = frequencies[t];
       }
@@ -3584,7 +3584,9 @@ void self_test(int test)
     reset_settings(M_LOW);
     setting.step_delay_mode = SD_NORMAL;
     setting.step_delay = 0;
-  } else if (test == 5) {
+  }
+#ifdef DOESNOTFIT
+  else if (test == 5) {
 //    reset_settings(M_LOW);                      // Make sure we are in a defined state
     in_selftest = true;
     switch (setting.test_argument) {
@@ -3622,6 +3624,7 @@ void self_test(int test)
     }
     in_selftest = false;
   }
+#endif
   show_test_info = FALSE;
   in_selftest = false;
   test_wait = false;