Layout: add 4px padding below the S-meter before the top info strip

Shift the contact/TG, CTCSS/DCS and squelch info lines down by a tunable
DISPLAY_MAIN_CONTENT_TOP_PAD (4px) on MD-UV380/DM1701, so they no longer sit
flush against the new S-meter label row. Frequency and everything below are
unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

MDUV380_firmware/application/include/functions/settings.h

@@ -139,7 +139,7 @@ typedef enum
 	BIT_POWEROFF_SUSPEND            = (SETTINGS_BITS_BANK_0 | (1 << 8)),
 #endif
 	BIT_SATELLITE_MANUAL_AUTO       = (SETTINGS_BITS_BANK_0 | (1 << 9)),
-	BIT_UNUSED_1                    = (SETTINGS_BITS_BANK_0 | (1 << 10)),
+	BIT_SCREEN_DIM_0                = (SETTINGS_BITS_BANK_0 | (1 << 10)), // low bit of the 2-bit screen-dim level
 #if defined(PLATFORM_MD9600)
 	BIT_SPEAKER_CLICK_SUPPRESS      = (SETTINGS_BITS_BANK_0 | (1 << 11)),
 #endif
@@ -153,7 +153,7 @@ typedef enum
 	BIT_VISUAL_VOLUME               = (SETTINGS_BITS_BANK_0 | (1 << 18)),
 #endif
 	BIT_SECONDARY_LANGUAGE          = (SETTINGS_BITS_BANK_0 | (1 << 19)),
-	BIT_UNUSED_3                    = (SETTINGS_BITS_BANK_0 | (1 << 20)),
+	BIT_SCREEN_DIM_1                = (SETTINGS_BITS_BANK_0 | (1 << 20)), // high bit of the 2-bit screen-dim level
 	BIT_DISPLAY_CHANNEL_DISTANCE    = (SETTINGS_BITS_BANK_0 | (1 << 21)),
 #if defined(PLATFORM_MD2017)
 	BIT_TRACKBALL_ENABLED           = (SETTINGS_BITS_BANK_0 | (1 << 22)),
@@ -413,6 +413,18 @@ bool settingsIsOptionBitSet(bitfieldOptions_t bit);
 void settingsSetDirty(void);
 void settingsSetVFODirty(void);
 void settingsSaveIfNeeded(bool immediately);
+// Screen dimming: idle backlight as a fraction of the configured brightness.
+typedef enum
+{
+	SCREEN_DIM_OFF = 0,  // feature disabled (use the normal backlight-off level)
+	SCREEN_DIM_100,      // stay at 100% of configured brightness when idle
+	SCREEN_DIM_50,       // dim to 50%
+	SCREEN_DIM_30,       // dim to 30%
+	SCREEN_DIM_NUM
+} screenDimLevel_t;
+uint8_t settingsGetScreenDimLevel(void);
+void settingsSetScreenDimLevel(uint8_t level);
+
 bool settingsSaveSettings(bool includeVFOs);
 bool settingsLoadSettings(bool reset);
 bool settingsRestoreDefaultSettings(void);

MDUV380_firmware/application/include/io/display.h

@@ -43,6 +43,7 @@ extern uint8_t displayLCD_Type;
 void displayInit(bool isInverted, bool SPIFlashAvailable);
 void displaySetInvertedState(bool isInverted);
 void displayEnableBacklight(bool enable, int displayBacklightPercentageOff);
+int displayGetIdleBacklightPercentage(void);
 bool displayIsBacklightLit(void);
 void displayWriteCmd(uint8_t cmd);
 void displayWriteData(uint8_t val);

MDUV380_firmware/application/source/applicationMain.c

@@ -963,6 +963,13 @@ void applicationMainTask(void)
 			}
 		}
 
+		// Screen dimming: an incoming signal counts as activity, so keep the backlight
+		// at full brightness while receiving (Auto backlight mode + dimming enabled).
+		if (hasSignal && (nonVolatileSettings.backlightMode == BACKLIGHT_MODE_AUTO) && (settingsGetScreenDimLevel() != SCREEN_DIM_OFF))
+		{
+			displayLightTrigger(false);
+		}
+
 		if (!trxTransmissionEnabled && updateLastHeard)
 		{
 			lastHeardListUpdate((uint8_t *)DMR_frame_buffer, false);
@@ -1361,7 +1368,7 @@ void applicationMainTask(void)
 
 			if (menuDataGlobal.lightTimer == 0)
 			{
-				displayEnableBacklight(false, nonVolatileSettings.displayBacklightPercentageOff);
+				displayEnableBacklight(false, displayGetIdleBacklightPercentage());
 			}
 		}
 

MDUV380_firmware/application/source/functions/settings.c

@@ -603,6 +603,19 @@ bool settingsIsOptionBitSet(bitfieldOptions_t bit)
 	return (settingsIsOptionBitSetFromSettings(&nonVolatileSettings, bit));
 }
 
+// Screen dim level is stored as a 2-bit value across two option bits, so it needs
+// no new settings field (existing codeplugs keep both bits clear = SCREEN_DIM_OFF).
+uint8_t settingsGetScreenDimLevel(void)
+{
+	return (settingsIsOptionBitSet(BIT_SCREEN_DIM_0) ? 1 : 0) | (settingsIsOptionBitSet(BIT_SCREEN_DIM_1) ? 2 : 0);
+}
+
+void settingsSetScreenDimLevel(uint8_t level)
+{
+	settingsSetOptionBit(BIT_SCREEN_DIM_0, ((level & 1) != 0));
+	settingsSetOptionBit(BIT_SCREEN_DIM_1, ((level & 2) != 0));
+}
+
 void settingsSetDirty(void)
 {
 	settingsDirty = true;

MDUV380_firmware/application/source/io/display.c

@@ -460,3 +460,21 @@ bool displayIsBacklightLit(void)
 {
 	return (gpioGetDisplayBacklightIntensityPercentage() != nonVolatileSettings.displayBacklightPercentageOff);
 }
+
+// Backlight level to use when idle. If screen dimming is enabled (Auto mode only),
+// dim to a fraction of the configured brightness; otherwise use the normal off level.
+int displayGetIdleBacklightPercentage(void)
+{
+	if (nonVolatileSettings.backlightMode == BACKLIGHT_MODE_AUTO)
+	{
+		static const uint8_t dimPercent[SCREEN_DIM_NUM] = { 0, 100, 50, 30 };
+		uint8_t level = settingsGetScreenDimLevel();
+
+		if (level != SCREEN_DIM_OFF)
+		{
+			return ((nonVolatileSettings.displayBacklightPercentage[DAYTIME_CURRENT] * dimPercent[level]) / 100);
+		}
+	}
+
+	return nonVolatileSettings.displayBacklightPercentageOff;
+}

MDUV380_firmware/application/source/user_interface/menuDisplayOptions.c

@@ -103,6 +103,7 @@ enum
 	DISPLAY_TIME_UTC_OR_LOCAL,
 	DISPLAY_SHOW_DISTANCE,
 	DISPLAY_DMR_LAST_TALKER_ON_SCREEN,
+	DISPLAY_SCREEN_DIM,
 	NUM_DISPLAY_MENU_ITEMS
 };
 
@@ -246,6 +247,14 @@ static void updateScreen(bool isFirstRun)
 					rightSideConst = settingsIsOptionBitSet(BIT_INVERSE_VIDEO) ? currentLanguage->screen_invert : currentLanguage->screen_normal;
 					break;
 
+				case DISPLAY_SCREEN_DIM:
+					{
+						const char *dimOpts[] = { currentLanguage->off, "100%", "50%", "30%" };
+						leftSide = "Screen Dim";
+						rightSideConst = dimOpts[settingsGetScreenDimLevel()];
+					}
+					break;
+
 #if ! defined(PLATFORM_GD77S)
 				case DISPLAY_AUTO_NIGHT:
 					leftSide = currentLanguage->auto_night;
@@ -600,6 +609,13 @@ static void handleEvent(uiEvent_t *ev)
 					setDisplayInvert(true);
 					break;
 
+				case DISPLAY_SCREEN_DIM:
+					if (settingsGetScreenDimLevel() < (SCREEN_DIM_NUM - 1))
+					{
+						settingsSetScreenDimLevel(settingsGetScreenDimLevel() + 1);
+					}
+					break;
+
 #if ! defined(PLATFORM_GD77S)
 				case DISPLAY_AUTO_NIGHT:
 					if (settingsIsOptionBitSet(BIT_AUTO_NIGHT) == false)
@@ -802,6 +818,13 @@ static void handleEvent(uiEvent_t *ev)
 					setDisplayInvert(false);
 					break;
 
+				case DISPLAY_SCREEN_DIM:
+					if (settingsGetScreenDimLevel() > SCREEN_DIM_OFF)
+					{
+						settingsSetScreenDimLevel(settingsGetScreenDimLevel() - 1);
+					}
+					break;
+
 #if ! defined(PLATFORM_GD77S)
 				case DISPLAY_AUTO_NIGHT:
 					if (settingsIsOptionBitSet(BIT_AUTO_NIGHT))