From 9ca3ccd7446633ca66ebfe66c0fef37a7922ba6e Mon Sep 17 00:00:00 2001
From: g4eml <colin@durbridge.me.uk>
Date: Sat, 2 Dec 2023 17:45:47 +0000
Subject: [PATCH] AM-Fix for Spectrum

---
 app/spectrum.c | 39 +++++++++++++++++++++++++++++++--------
 ui/main.c      | 19 ++++++++++---------
 ui/main.h      |  1 +
 3 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/app/spectrum.c b/app/spectrum.c
index 43c2a4c..dcf86bf 100644
--- a/app/spectrum.c
+++ b/app/spectrum.c
@@ -18,6 +18,8 @@
 #include "driver/backlight.h"
 #include "audio.h"
 #include "ui/helper.h"
+#include "am_fix.h"
+#include "ui/main.h"
 
 struct FrequencyBandInfo {
     uint32_t lower;
@@ -30,6 +32,7 @@ struct FrequencyBandInfo {
 
 const uint16_t RSSI_MAX_VALUE = 65535;
 
+
 static uint16_t R30, R37, R3D, R43, R47, R48, R7E;
 static uint32_t initialFreq;
 static char String[32];
@@ -68,7 +71,7 @@ SpectrumSettings settings = {stepsCount: STEPS_64,
 uint32_t fMeasure = 0;
 uint32_t currentFreq, tempFreq;
 uint16_t rssiHistory[128];
-
+int vfo;
 uint8_t freqInputIndex = 0;
 uint8_t freqInputDotIndex = 0;
 KEY_Code_t freqInputArr[10];
@@ -99,7 +102,10 @@ static uint8_t DBm2S(int dbm) {
   return i;
 }
 
-static int Rssi2DBm(uint16_t rssi) { return (rssi >> 1) - 160; }
+static int Rssi2DBm(uint16_t rssi) 
+{    
+      return  (rssi / 2) - 160 + dBmCorrTable[gRxVfo->Band];
+}
 
 static uint16_t GetRegMenuValue(uint8_t st) {
   RegisterSpec s = registerSpecs[st];
@@ -276,7 +282,15 @@ uint16_t GetRssi() {
   while ((BK4819_ReadRegister(0x63) & 0b11111111) >= 255) {
     SYSTICK_DelayUs(100);
   }
-  return BK4819_GetRSSI();
+  if(settings.modulationType == MODULATION_AM)
+      {
+      return BK4819_GetRSSI() -  rssi_gain_diff[vfo];          //return the corrected RSSI to allow for AM_Fixs AGC action. 
+      }
+   else
+     {
+     return BK4819_GetRSSI();
+     }
+  
 }
 
 static void ToggleAudio(bool on) {
@@ -383,7 +397,7 @@ static void Measure() { rssiHistory[scanInfo.i] = scanInfo.rssi = GetRssi(); }
 
 static uint16_t dbm2rssi(int dBm)
 {
-  return (dBm + 160)*2;
+  return (dBm + 160 - dBmCorrTable[gRxVfo->Band])*2;
 }
 
 static void ClampRssiTriggerLevel()
@@ -475,6 +489,9 @@ static void ToggleModulation() {
     settings.modulationType = MODULATION_FM;
   }
   RADIO_SetModulation(settings.modulationType);
+  BK4819_SetAGC(settings.modulationType != MODULATION_AM || !gSetting_AM_fix);
+  BK4819_InitAGC();
+  RelaunchScan();
   redrawScreen = true;
 }
 
@@ -588,7 +605,7 @@ uint8_t Rssi2PX(uint16_t rssi, uint8_t pxMin, uint8_t pxMax) {
 
   const uint8_t PX_RANGE = pxMax - pxMin;
 
-  int dbm = clamp(rssi - (160 << 1), DB_MIN, DB_MAX);
+  int dbm = clamp(Rssi2DBm(rssi) << 1, DB_MIN, DB_MAX);
 
   return ((dbm - DB_MIN) * PX_RANGE + DB_RANGE / 2) / DB_RANGE + pxMin;
 }
@@ -1104,6 +1121,11 @@ static void UpdateListening() {
 }
 
 static void Tick() {
+
+  if(settings.modulationType == MODULATION_AM)
+    {
+      AM_fix_10ms(vfo);                //allow AM_Fix to apply its AGC action
+    }
   if (!preventKeypress) {
     HandleUserInput();
   }
@@ -1133,8 +1155,8 @@ static void Tick() {
 
 void APP_RunSpectrum() {
   // TX here coz it always? set to active VFO
-  currentFreq = initialFreq =
-      gEeprom.VfoInfo[gEeprom.TX_VFO].pRX->Frequency;
+  vfo =  gEeprom.TX_VFO;
+  currentFreq = initialFreq = gEeprom.VfoInfo[vfo].pRX->Frequency - ((GetStepsCount()/2) * GetScanStep());                          //set the current frequency in the middle of the display
 
   BackupRegisters();
 
@@ -1144,7 +1166,8 @@ void APP_RunSpectrum() {
   newScanStart = true;
 
   ToggleRX(true), ToggleRX(false); // hack to prevent noise when squelch off
-  RADIO_SetModulation(settings.modulationType = MODULATION_FM);
+  RADIO_SetModulation(settings.modulationType = gRxVfo->Modulation);
+  BK4819_SetAGC(settings.modulationType != MODULATION_AM || !gSetting_AM_fix);
   BK4819_SetFilterBandwidth(settings.listenBw = BK4819_FILTER_BW_WIDE, false);
 
   RelaunchScan();
diff --git a/ui/main.c b/ui/main.c
index 2b991c3..c7424b1 100644
--- a/ui/main.c
+++ b/ui/main.c
@@ -39,6 +39,16 @@
 
 center_line_t center_line = CENTER_LINE_NONE;
 
+const int8_t dBmCorrTable[7] = {
+			-15, // band 1
+			-25, // band 2
+			-20, // band 3
+			-4, // band 4
+			-7, // band 5
+			-6, // band 6
+			 -1  // band 7
+		};
+
 // ***************************************************************************
 
 static void DrawSmallAntennaAndBars(uint8_t *p, unsigned int level)
@@ -176,15 +186,6 @@ static void DisplayRSSIBar(const int16_t rssi, const bool now)
 		if (now)
 			memset(p_line, 0, LCD_WIDTH);
 		
-		const int8_t dBmCorrTable[7] = {
-			-15, // band 1
-			-25, // band 2
-			-20, // band 3
-			-4, // band 4
-			-7, // band 5
-			-6, // band 6
-			 -1  // band 7
-		};
 
 		const int16_t      s0_dBm       = -130;                  // S0 .. base level
 		const int16_t      rssi_dBm     = (rssi / 2) - 160 + dBmCorrTable[gRxVfo->Band];
diff --git a/ui/main.h b/ui/main.h
index 80024f9..05205aa 100644
--- a/ui/main.h
+++ b/ui/main.h
@@ -29,6 +29,7 @@ enum center_line_t {
 typedef enum center_line_t center_line_t;
 
 extern center_line_t center_line;
+extern const int8_t dBmCorrTable[7];
 
 void UI_DisplayAudioBar(void);
 void UI_UpdateRSSI(const int16_t rssi, const int vfo);