Keep reflevel

nanovna.h

@@ -816,6 +816,7 @@ void self_test(int);
 //extern int setting_test;
 void wait_user(void);
 void calibrate(void);
+float to_dBm(float);
 
 enum {
   M_OFF, M_IMD, M_OIP3, M_PHASE_NOISE, M_STOP_BAND, M_PASS_BAND, M_LINEARITY

plot.c

@@ -457,10 +457,10 @@ value(const float v)
   switch(setting.unit)
   {
   case U_DBMV:
-    return v+ 30.0 + 20.0*log10(sqrt(50));
+    return v + 30.0 + 20.0*log10(sqrt(50));
     break;
   case U_DBUV:
-    return v+ 90.0 + 20.0*log10(sqrt(50.0));
+    return v + 90.0 + 20.0*log10(sqrt(50.0));
     break;
   case U_MVOLT:
     return pow(10, (v-30.0)/20.0) * sqrt(50.0) * 1000.0;
@@ -480,6 +480,34 @@ value(const float v)
 
 }
 
+float
+to_dBm(const float v)
+{
+  switch(setting.unit)
+  {
+  case U_DBMV:
+    return v - 30.0 - 20.0*log10(sqrt(50));
+    break;
+  case U_DBUV:
+    return v - 90.0 - 20.0*log10(sqrt(50.0));
+    break;
+  case U_MVOLT:
+    return log10( v / (sqrt(50.0) * 1000.0)) * 20.0 + 30.0 ;
+    break;
+  case U_UVOLT:
+    return log10(v / (sqrt(50.0) * 1000000.0))*20.0 + 30.0;
+    break;
+  case U_MWATT:
+    return log10(v)*10.0;
+    break;
+  case U_UWATT:
+    return log10(v/1000.0)*10.0;
+    break;
+  }
+//  case U_DBM:
+    return v;  // raw data is in logmag*10 format
+
+}
 
 
 #ifdef __VNA_

sa_core.c

@@ -217,10 +217,22 @@ void set_IF(int f)
 
 void set_unit(int u)
 {
-  if (UNIT_IS_LINEAR(setting.unit) && !UNIT_IS_LINEAR(u)) {
+  float r = to_dBm(setting.reflevel);   // Get neutral unit
+  float s = to_dBm(setting.scale);
+//  float t = setting.trigger;            // Is always in dBm
+  // float m = r - NGRIDSY*s;
+
+  setting.unit = u;                     // Switch unit
+
+  r = value(r);                         // Convert to target unit
+  s = value(s);
+  if (UNIT_IS_LINEAR(setting.unit)) {
+    set_reflevel(r);
+    set_scale(r/10.0);
+  } else {
+    r = 10 * round((r*1.2)/10.0);
     set_scale(10);
   }
-  setting.unit = u;
   dirty = true;
 }
 

ui_sa.c

@@ -423,7 +423,7 @@ static const char * const keypad_mode_label[] = {
 static const char * const keypad_mode_label[] = {
   "error", "START", "STOP", "CENTER", "SPAN", "FREQ", "REFPOS", "SCALE", // 0-7
   "\2ATTENUATE\0 0-31dB", "\2ACTUAL\0POWER", "IF", "\2SAMPLE\0TIME", "DRIVE", "LEVEL", "LEVEL", "LEVEL", // 8-15
-  "OFFSET" , "REPEATS", "OFFSET", "TRIGGER", "\2LEVEL\0SWEEP", "\2SWEEP\0SECONDS"// 16-
+  "OFFSET" , "REPEATS", "OFFSET", "\2TRIGGER\0LEVEL", "\2LEVEL\0SWEEP", "\2SWEEP\0SECONDS"// 16-
 };
 #endif
 
@@ -1843,7 +1843,7 @@ set_numeric_value(void)
     set_sweep_time(uistat.value);
     break;
   case KM_TRIGGER:
-    set_trigger_level(uistat.value);
+    set_trigger_level(to_dBm(uistat.value));
     break;
   }
 }