AM fix modification

Makefile

@@ -33,7 +33,7 @@ ENABLE_BOOT_BEEPS             := 0
 ENABLE_SHOW_CHARGE_LEVEL      := 0
 ENABLE_REVERSE_BAT_SYMBOL     := 0
 ENABLE_NO_CODE_SCAN_TIMEOUT   := 1
-ENABLE_AM_FIX                 := 0
+ENABLE_AM_FIX                 := 1
 ENABLE_SQUELCH_MORE_SENSITIVE := 1
 ENABLE_FASTER_CHANNEL_SCAN    := 1
 ENABLE_RSSI_BAR               := 1

am_fix.c

@@ -29,6 +29,7 @@
 #include "frequencies.h"
 #include "functions.h"
 #include "misc.h"
+#include "settings.h"
 
 #ifdef ENABLE_AM_FIX
 
@@ -186,7 +187,7 @@ static const t_gain_table gain_table[] =
 	{0x03FF,  0},   // 91 .. 3 7 3 7 ..   0dB   0dB  0dB   0dB ..   0dB
 };
 
-static const unsigned int original_index = 85;
+static const unsigned int original_index = ARRAY_SIZE(gain_table) - 7;
 
 #ifdef ENABLE_AM_FIX_SHOW_DATA
 	// display update rate
@@ -212,6 +213,9 @@ const unsigned max_index = ARRAY_SIZE(gain_table) - 1;
 // -89dBm, any higher and the AM demodulator starts to saturate/clip/distort
 const int16_t desired_rssi = (-89 + 160) * 2;
 
+int8_t currentGainDiff;
+bool enabled = true;
+
 void AM_fix_init(void)
 {	// called at boot-up
 	for (int i = 0; i < 2; i++) {
@@ -242,7 +246,7 @@ void AM_fix_reset(const unsigned vfo)
 //
 void AM_fix_10ms(const unsigned vfo, bool force)
 {
-	if(vfo > 1)
+	if(!gSetting_AM_fix || !enabled || vfo > 1 )
 		return;
 
 	if(!force) switch (gCurrentFunction)
@@ -254,7 +258,6 @@ void AM_fix_10ms(const unsigned vfo, bool force)
 #ifdef ENABLE_AM_FIX_SHOW_DATA
 			counter = display_update_rate;  // queue up a display update as soon as we switch to RX mode
 #endif
-			AM_fix_reset(vfo);
 			return;
 
 		// only adjust stuff if we're in one of these modes
@@ -273,6 +276,12 @@ void AM_fix_10ms(const unsigned vfo, bool force)
 	}
 #endif
 
+	static uint32_t lastFreq[2];
+	if(gEeprom.VfoInfo[vfo].pRX->Frequency != lastFreq[vfo]) {
+		lastFreq[vfo] = gEeprom.VfoInfo[vfo].pRX->Frequency;
+		AM_fix_reset(vfo);
+	}
+
 	int16_t rssi;
 	{	// sample the current RSSI level
 		// average it with the previous rssi (a bit of noise/spike immunity)
@@ -348,7 +357,7 @@ void AM_fix_10ms(const unsigned vfo, bool force)
 
 		// remember the new table index
 		gain_table_index_prev[vfo] = index;
-
+		currentGainDiff = gain_table[original_index].gain_dB - gain_table[index].gain_dB;
 		BK4819_WriteRegister(BK4819_REG_13, gain_table[index].reg_val);
 	}
 
@@ -370,5 +379,13 @@ void AM_fix_print_data(const unsigned vfo, char *s) {
 }
 #endif
 
+int8_t AM_fix_get_gain_diff()
+{
+	return currentGainDiff;
+}
 
+void AM_fix_enable(bool on)
+{
+	enabled = on;
+}
 #endif

am_fix.h

@@ -22,11 +22,14 @@
 
 #ifdef ENABLE_AM_FIX
 	void AM_fix_init(void);
+	void AM_fix_reset(const unsigned vfo);
 	void AM_fix_10ms(const unsigned vfo, bool force);
 	#ifdef ENABLE_AM_FIX_SHOW_DATA
 		void AM_fix_print_data(const unsigned vfo, char *s);
 	#endif
-		
+	int8_t AM_fix_get_gain_diff();
+	void AM_fix_enable(bool on);
+
 #endif
 
 #endif

app/app.c

@@ -1121,7 +1121,7 @@ void APP_TimeSlice10ms(void)
 	#endif
 
 	#ifdef ENABLE_AM_FIX
-		if (gRxVfo->Modulation == MODULATION_AM && gSetting_AM_fix)
+		if (gRxVfo->Modulation == MODULATION_AM)
 			AM_fix_10ms(gEeprom.RX_VFO, false);
 	#endif
 

app/spectrum.c

@@ -113,8 +113,7 @@ static uint16_t GetRegMenuValue(uint8_t st) {
 
 void LockAGC()
 {
-  if(!lockAGC)
+  RADIO_SetupAGC(true, lockAGC);
-    BK4819_SetAGC(0);
   lockAGC = true;
 }
 
@@ -492,13 +491,6 @@ static void ToggleModulation() {
   }
   RADIO_SetModulation(settings.modulationType);
 
-#ifdef ENABLE_AM_FIX
-  if(gSetting_AM_fix && settings.modulationType != MODULATION_AM) {
-    BK4819_InitAGC(false);
-    BK4819_SetAGC(1);
-  }
-#endif
-
   RelaunchScan();
   redrawScreen = true;
 }
@@ -1178,13 +1170,6 @@ void APP_RunSpectrum() {
   ToggleRX(true), ToggleRX(false); // hack to prevent noise when squelch off
   RADIO_SetModulation(settings.modulationType = gRxVfo->Modulation);
 
-#ifdef ENABLE_AM_FIX
-  if(settings.modulationType != MODULATION_AM) {
-    BK4819_InitAGC(false);
-    BK4819_SetAGC(true);
-  }
-#endif
-
   BK4819_SetFilterBandwidth(settings.listenBw = BK4819_FILTER_BW_WIDE, false);
 
   RelaunchScan();

radio.c

@@ -772,12 +772,7 @@ void RADIO_SetupRegisters(bool switchToForeground)
 		}
 	#endif
 
-#ifdef ENABLE_AM_FIX
+	RADIO_SetupAGC(false, false);
-	if(gSetting_AM_fix) {
-		BK4819_SetAGC(true);
-		BK4819_InitAGC(false);
-	}
-#endif
 
 	// enable/disable BK4819 selected interrupts
 	BK4819_WriteRegister(BK4819_REG_3F, InterruptMask);
@@ -926,12 +921,36 @@ void RADIO_SetModulation(ModulationMode_t modulation)
 	BK4819_SetRegValue(afDacGainRegSpec, 0xF);
 	BK4819_WriteRegister(BK4819_REG_3D, modulation == MODULATION_USB ? 0 : 0x2AAB);
 	BK4819_SetRegValue(afcDisableRegSpec, modulation != MODULATION_FM);
-#ifdef ENABLE_AM_FIX
+
-	if(modulation == MODULATION_AM && gSetting_AM_fix) {
+	RADIO_SetupAGC(modulation == MODULATION_AM, false);
-		BK4819_SetAGC(0);
+}
+
+void RADIO_SetupAGC(bool listeningAM, bool disable)
+{
+	static uint8_t lastSettings;
+	uint8_t newSettings = (listeningAM << 1) | (disable << 1);
+	if(lastSettings == newSettings)
+		return;
+	lastSettings = newSettings;
+
+
+	if(!listeningAM) { // if not actively listening AM we don't need any AM specific regulation
+		BK4819_SetAGC(1);
+		BK4819_InitAGC(false);
 	}
+	else {
+#ifdef ENABLE_AM_FIX		
+		if(gSetting_AM_fix) { // if AM fix active lock AGC so AM-fix can do it's job
+			BK4819_SetAGC(0);
+			AM_fix_enable(!disable);
+		}
+		else
 #endif
-	BK4819_InitAGC(modulation == MODULATION_AM);
+		{
+			BK4819_SetAGC(!disable);
+			BK4819_InitAGC(true);
+		}
+	}
 }
 
 void RADIO_SetVfoState(VfoState_t State)
@@ -1149,4 +1168,4 @@ void RADIO_SendEndOfTransmission(void)
 	}
 
 	BK4819_ExitDTMF_TX(true);
-}
+}

radio.h

@@ -159,6 +159,7 @@ void     RADIO_SetupRegisters(bool bSwitchToFunction0);
 	void RADIO_ConfigureNOAA(void);
 #endif
 void     RADIO_SetTxParameters(void);
+void 	 RADIO_SetupAGC(bool listeningAM, bool disable);
 void     RADIO_SetModulation(ModulationMode_t modulation);
 void     RADIO_SetVfoState(VfoState_t State);
 void     RADIO_PrepareTX(void);

ui/main.c

@@ -189,7 +189,13 @@ void DisplayRSSIBar(const bool now)
 	
 
 	const int16_t      s0_dBm       = -130;                  // S0 .. base level
-	const int16_t      rssi_dBm     = BK4819_GetRSSI_dBm() + dBmCorrTable[gRxVfo->Band];
+	const int16_t      rssi_dBm     = 
+		BK4819_GetRSSI_dBm()
+#ifdef ENABLE_AM_FIX
+		+ (gSetting_AM_fix ? AM_fix_get_gain_diff() : 0)
+#endif	
+		+ dBmCorrTable[gRxVfo->Band];
+	
 
 	const uint8_t s_level = MIN(MAX((rssi_dBm - s0_dBm) / 6, 0), 9); // S0 - S9
 	uint8_t overS9dBm = MIN(MAX(rssi_dBm - (s0_dBm + 9*6), 0), 99);