A lot of changes

- Store actual frequency in config
- Measure FM deviation
- Center zoom updated to work with dragged marker
- Improved touch calibration markers

main.c

@@ -880,6 +880,7 @@ config_t config = {
   .high_level_offset =      100,    // Uncalibrated
   .correction_frequency = { 10000, 100000, 200000, 500000, 50000000, 140000000, 200000000, 300000000, 330000000, 350000000 },
   .correction_value = { +6.0, +2.8, +1.6, -0.4, 0.0, -0.4, +0.4, +3.0, +4.0, +8.1 },
+  .setting_frequency_10mhz = 10000000,
   .cor_am = -14,
   .cor_wfm = -17,
   .cor_nfm = -17,

nanovna.h

@@ -469,6 +469,7 @@ typedef struct config {
   int8_t    cor_am;
   int8_t    cor_wfm;
   int8_t    cor_nfm;
+  uint32_t  setting_frequency_10mhz;
   int8_t    dummy;
 //  uint8_t _reserved[22];
   uint32_t checksum;

plot.c

@@ -2123,6 +2123,12 @@ static void cell_draw_marker_info(int x0, int y0)
 #endif
         plot_printf(buf, sizeof buf, "DEPTH: %3d%%", depth);
         goto show_computed;
+      } else if (setting.measurement == M_FM){
+        int32_t dev = ( markers[2].frequency - markers[1].frequency - actual_rbw_x10 * 100 ) >> 1;
+        if (dev < 0 )
+          break;
+        plot_printf(buf, sizeof buf, "DEVIATION:%6.1qHz", dev);
+        goto show_computed;
       }
     }
     if (i >= 2 && setting.measurement == M_THD) {

sa_core.c

@@ -84,8 +84,8 @@ void update_min_max_freq(void)
     minFreq = 00000000;
     maxFreq = 2000000000;
 #else
-    minFreq = 24*setting_frequency_10mhz;
+    minFreq = 24*config.setting_frequency_10mhz;
-    maxFreq = 96*setting_frequency_10mhz;
+    maxFreq = 96*config.setting_frequency_10mhz;
 #endif
     break;
   case M_GENHIGH:
@@ -256,6 +256,19 @@ void set_gridlines(int d)
   update_grid();
 }
 
+//int setting_frequency_10mhz = 10000000;
+
+void set_10mhz(uint32_t f)
+{
+  if (f < 9000000 || f > 11000000)
+    return;
+  config.setting_frequency_10mhz = f;
+  config_save();
+  dirty = true;
+  update_grid();
+}
+
+
 void set_measurement(int m)
 {
   setting.measurement = m;
@@ -1318,6 +1331,21 @@ int binary_search_frequency(int f)      // Search which index in the frequency t
   return -1;
 }
 
+uint32_t interpolate_maximum(int m)
+{
+  const int idx          = markers[m].index;
+  markers[m].frequency = frequencies[idx];
+  if (idx > 0 && idx < sweep_points-1)
+  {
+    const float y1         = actual_t[idx - 1];
+    const float y2         = actual_t[idx + 0];
+    const float y3         = actual_t[idx + 1];
+    const float d          = 0.5f * (y1 - y3) / ((y1 - (2 * y2) + y3) + 1e-12f);
+    //const float bin      = (float)idx + d;
+    const int32_t delta_Hz = abs((int64_t)frequencies[idx + 0] - frequencies[idx + 1]);
+    markers[m].frequency   += (int32_t)(delta_Hz * d);
+  }
+}
 
 #define MAX_MAX 4
 int
@@ -1382,7 +1410,8 @@ search_maximum(int m, int center, int span)
     }
   }
   markers[m].index = max_index[0];
-  markers[m].frequency = frequencies[markers[m].index];
+  interpolate_maximum(m);
+//  markers[m].frequency = frequencies[markers[m].index];
   return found;
 }
 
@@ -2353,7 +2382,8 @@ sweep_again:                                // stay in sweep loop when output mo
       while (m < MARKERS_MAX) {
         if (markers[m].enabled && markers[m].mtype & M_TRACKING) {   // Available marker found
           markers[m].index = max_index[i];
-          markers[m].frequency = frequencies[markers[m].index];
+          interpolate_maximum(m);
+          // markers[m].frequency = frequencies[markers[m].index];
 #if 0
           float v = actual_t[markers[m].index] - 10.0;              // -10dB points
           int index = markers[m].index;
@@ -2375,19 +2405,7 @@ sweep_again:                                // stay in sweep loop when output mo
 
 #endif
 
-#if 1                                                        // Hyperbolic interpolation, can be removed to save memory
+          interpolate_maximum(m);
-          const int idx          = markers[m].index;
-          if (idx > 0 && idx < sweep_points-1)
-          {
-            const float y1         = actual_t[idx - 1];
-            const float y2         = actual_t[idx + 0];
-            const float y3         = actual_t[idx + 1];
-            const float d          = 0.5f * (y1 - y3) / ((y1 - (2 * y2) + y3) + 1e-12f);
-            //const float bin      = (float)idx + d;
-            const int32_t delta_Hz = abs((int64_t)frequencies[idx + 0] - frequencies[idx + 1]);
-            markers[m].frequency   += (int32_t)(delta_Hz * d);
-          }
-#endif
           m++;
           break;                          // Next maximum
         }
@@ -2398,7 +2416,7 @@ sweep_again:                                // stay in sweep loop when output mo
     while (m < MARKERS_MAX) {                  // Insufficient maxima found
       if (markers[m].enabled && markers[m].mtype & M_TRACKING) {    // More available markers found
         markers[m].index = 0;                             // Enabled but no max so set to left most frequency
-        markers[m].frequency = frequencies[markers[m].index];
+        markers[m].frequency = frequencies[0];
       }
       m++;                              // Try next marker
     }
@@ -2437,7 +2455,7 @@ sweep_again:                                // stay in sweep loop when output mo
       markers[2].index =  marker_search_right_min(markers[0].index);
       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
+    } else if ((setting.measurement == M_PASS_BAND || setting.measurement == M_FM)  && markers[0].index > 10) {      // ----------------Pass band measurement
       int t = 0;
       float v = actual_t[markers[0].index] - 3.0;
       while (t < markers[0].index && actual_t[t+1] < v)                                        // Find left -3dB point

si4432.c

@@ -118,13 +118,6 @@ static void shiftOutBuf(uint8_t *buf, uint16_t size) {
 }
 #endif
 
-int setting_frequency_10mhz = 10000000;
-
-void set_10mhz(uint32_t f)
-{
-  setting_frequency_10mhz = f;
-}
-
 #ifdef __SI4432__
 #define CS_SI0_HIGH     palSetPad(GPIOC, GPIO_RX_SEL)
 #define CS_SI1_HIGH     palSetPad(GPIOC, GPIO_LO_SEL)
@@ -376,8 +369,8 @@ void SI4432_Set_Frequency ( uint32_t Freq ) {
     hbsel = 0;
   }
   uint8_t sbsel = 1 << 6;
-  uint32_t N = (Freq / setting_frequency_10mhz - 24)&0x1F;
+  uint32_t N = (Freq / config.setting_frequency_10mhz - 24)&0x1F;
-  uint32_t K = Freq % setting_frequency_10mhz;
+  uint32_t K = Freq % config.setting_frequency_10mhz;
   uint32_t Carrier = (K<<2) / 625;
   uint8_t Freq_Band = N | hbsel | sbsel;
 //  int count = 0;

ui.c

@@ -333,7 +333,8 @@ touch_cal_exec(void)
   ili9341_clear_screen();
   ili9341_line(0, 0, 0, 32);
   ili9341_line(0, 0, 32, 0);
-  ili9341_drawstring("TOUCH UPPER LEFT", 10, 10);
+  ili9341_line(0, 0, 32, 32);
+  ili9341_drawstring("TOUCH UPPER LEFT", 40, 40);
 
   touch_wait_release();
   x1 = last_touch_x;
@@ -342,7 +343,8 @@ touch_cal_exec(void)
   ili9341_clear_screen();
   ili9341_line(LCD_WIDTH-1, LCD_HEIGHT-1, LCD_WIDTH-1, LCD_HEIGHT-32);
   ili9341_line(LCD_WIDTH-1, LCD_HEIGHT-1, LCD_WIDTH-32, LCD_HEIGHT-1);
-  ili9341_drawstring("TOUCH LOWER RIGHT", 230, 220);
+  ili9341_line(LCD_WIDTH-1, LCD_HEIGHT-1, LCD_WIDTH-32, LCD_HEIGHT-32);
+  ili9341_drawstring("TOUCH LOWER RIGHT", 210, 200);
 
   touch_wait_release();
   x2 = last_touch_x;
@@ -844,7 +846,10 @@ static UI_FUNCTION_CALLBACK(menu_marker_search_cb)
   }
   if (i != -1) {
     markers[active_marker].index = i;
-    markers[active_marker].frequency = frequencies[i];
+    if (data > 1) // Maximum related
+      interpolate_maximum(active_marker);
+    else
+      markers[active_marker].frequency = frequencies[i];
   }
   draw_menu();
   redraw_marker(active_marker);
@@ -2114,7 +2119,8 @@ lever_search_marker(int status)
       i = marker_search_right_max(markers[active_marker].index);
     if (i != -1) {
       markers[active_marker].index = i;
-      markers[active_marker].frequency = frequencies[i];
+      interpolate_maximum(active_marker);
+//      markers[active_marker].frequency = frequencies[i];
     }
     redraw_marker(active_marker);
   }
@@ -2146,6 +2152,7 @@ lever_zoom_span(int status)
   uint32_t span = get_sweep_frequency(ST_SPAN);
   if (uistat.auto_center_marker) {
     uint32_t freq = get_marker_frequency(active_marker);
+    search_maximum(active_marker, freq, 10 );
     if (freq != 0)
       set_sweep_frequency(ST_CENTER, freq);
   }

ui_sa.c

@@ -757,7 +757,7 @@ static UI_FUNCTION_ADV_CALLBACK(menu_measure_acb)
 #ifdef __MEASURE__
   switch(data) {
     case M_OFF:                                     // Off
-      reset_settings(setting.mode);
+//      reset_settings(setting.mode);
       set_measurement(M_OFF);
       break;
     case M_IMD:                                     // IMD
@@ -884,16 +884,26 @@ static UI_FUNCTION_ADV_CALLBACK(menu_measure_acb)
       reset_settings(setting.mode);
       for (int i = 0; i< 3; i++) {
         markers[i].enabled = M_ENABLED;
-        markers[i].mtype = M_DELTA | M_TRACKING;
+        markers[i].mtype = M_DELTA;
       }
-      markers[0].mtype = M_REFERENCE | M_TRACKING;
+      markers[0].mtype = M_REFERENCE;
       kp_help_text = "Frequency of signal";
       ui_mode_keypad(KM_CENTER);
       ui_process_keypad();
-      kp_help_text = "Frequency deviation";
+      set_marker_frequency(0, uistat.value);
+      kp_help_text = "Modulation frequency: 1 .. 2.5kHz";
       ui_mode_keypad(KM_SPAN);
       ui_process_keypad();
-      set_sweep_frequency(ST_SPAN, uistat.value*30);
+      if (uistat.value < 1000 || uistat.value > 2500)
+        break;
+      set_RBW(uistat.value/100);
+      // actual_rbw_x10
+      kp_help_text = "Frequency deviation: 3 .. 500kHz";
+      ui_mode_keypad(KM_SPAN);
+      ui_process_keypad();
+      if (uistat.value < 12000)
+        uistat.value = 12000;   // minimum span
+      set_sweep_frequency(ST_SPAN, uistat.value*4);
       set_measurement(M_FM);
       break;
     case M_THD:
@@ -1013,6 +1023,7 @@ static UI_FUNCTION_ADV_CALLBACK(menu_marker_select_acb)
     return;
   }
   markers[data-1].enabled = true;
+//  interpolate_maximum(data-1);        // possibly not a maximum
   markers[data-1].frequency = frequencies[markers[data-1].index];
   active_marker_select(data-1);
   menu_push_submenu(menu_marker_modify);
@@ -2016,7 +2027,7 @@ static void fetch_numeric_target(void)
     plot_printf(uistat.text, sizeof uistat.text, "%3d", ((int32_t)uistat.value));
     break;
   case KM_10MHZ:
-    uistat.value = setting_frequency_10mhz;
+    uistat.value = config.setting_frequency_10mhz;
     plot_printf(uistat.text, sizeof uistat.text, "%3.6fMHz", uistat.value / 1000000.0);
     break;
   case KM_OFFSET:
@@ -2128,7 +2139,6 @@ set_numeric_value(void)
     break;
   case KM_10MHZ:
     set_10mhz(uistat.value);
-    dirty = true;
     break;
   case KM_OFFSET:
     set_offset(uistat.value);