UA1ZBE Custom Firmware v1.0

Features:
- VFO mode with direct frequency input
- POCSAG decoder (512/1200 baud) with BCH(31,21) correction
- Full-screen Spectrum analyzer
- FM Radio receiver
- RSSI signal indicator overlay
- Custom boot splash (UA1ZBE / POCSAG pager / build date)

Architecture:
- app/mode.c — mode dispatcher (VFO/POCSAG/Spectrum/FM)
- app/boot_splash.c — 2-second boot splash
- app/pocsag/ — POCSAG decoder + BCH correction
- app/display_rssi.c — RSSI indicator
- main.c — entry point with custom init
- syscalls.c — bare-metal _sbrk stub

Build: arm-none-eabi-gcc -Os -flto -Wall -Werror -Wextra
Size: 57.9KB Flash / 3.6KB RAM

Controls:
- 0-9: Direct frequency input (VFO)
- SK2: POCSAG mode
- SK1: Spectrum analyzer
- 0: FM Radio
- EXIT: Return to VFO
- F/*: Toggle 512/1200 baud (in POCSAG)

ui/lock.c

@@ -0,0 +1,161 @@
+/* Copyright 2023 Dual Tachyon
+ * https://github.com/DualTachyon
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *     Unless required by applicable law or agreed to in writing, software
+ *     distributed under the License is distributed on an "AS IS" BASIS,
+ *     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *     See the License for the specific language governing permissions and
+ *     limitations under the License.
+ */
+
+#ifdef ENABLE_PWRON_PASSWORD
+
+#include <string.h>
+
+#include "ARMCM0.h"
+#include "app/uart.h"
+#include "audio.h"
+#include "driver/keyboard.h"
+#include "driver/st7565.h"
+#include "misc.h"
+#include "settings.h"
+#include "ui/helper.h"
+#include "ui/inputbox.h"
+#include "ui/lock.h"
+
+static void Render(void)
+{
+	unsigned int i;
+	char         String[7];
+
+	memset(gStatusLine,  0, sizeof(gStatusLine));
+	UI_DisplayClear();
+
+	UI_PrintString("LOCK", 0, 127, 1, 10);
+	for (i = 0; i < 6; i++)
+		String[i] = (gInputBox[i] == 10) ? '-' : '*';
+	String[6] = 0;
+	UI_PrintString(String, 0, 127, 3, 12);
+
+	ST7565_BlitStatusLine();
+	ST7565_BlitFullScreen();
+}
+
+void UI_DisplayLock(void)
+{
+	KEY_Code_t  Key;
+	BEEP_Type_t Beep;
+
+	gUpdateDisplay = true;
+
+	memset(gInputBox, 10, sizeof(gInputBox));
+
+	while (1)
+	{
+		while (!gNextTimeslice) {}
+
+		// TODO: Original code doesn't do the below, but is needed for proper key debounce
+
+		gNextTimeslice = false;
+
+		Key = KEYBOARD_Poll();
+
+		if (gKeyReading0 == Key)
+		{
+			if (++gDebounceCounter == key_debounce_10ms)
+			{
+				if (Key == KEY_INVALID)
+				{
+					gKeyReading1 = KEY_INVALID;
+				}
+				else
+				{
+					gKeyReading1 = Key;
+
+					switch (Key)
+					{
+						case KEY_0:
+						case KEY_1:
+						case KEY_2:
+						case KEY_3:
+						case KEY_4:
+						case KEY_5:
+						case KEY_6:
+						case KEY_7:
+						case KEY_8:
+						case KEY_9:
+							INPUTBOX_Append(Key - KEY_0);
+
+							if (gInputBoxIndex < 6)   // 6 frequency digits
+							{
+								Beep = BEEP_1KHZ_60MS_OPTIONAL;
+							}
+							else
+							{
+								uint32_t Password;
+
+								gInputBoxIndex = 0;
+								Password = StrToUL(INPUTBOX_GetAscii());
+
+								if ((gEeprom.POWER_ON_PASSWORD) == Password)
+								{
+									AUDIO_PlayBeep(BEEP_1KHZ_60MS_OPTIONAL);
+									return;
+								}
+
+								memset(gInputBox, 10, sizeof(gInputBox));
+
+								Beep = BEEP_500HZ_60MS_DOUBLE_BEEP_OPTIONAL;
+							}
+
+							AUDIO_PlayBeep(Beep);
+
+							gUpdateDisplay = true;
+							break;
+
+						case KEY_EXIT:
+							if (gInputBoxIndex > 0)
+							{
+								gInputBox[--gInputBoxIndex] = 10;
+								gUpdateDisplay = true;
+							}
+
+							AUDIO_PlayBeep(BEEP_1KHZ_60MS_OPTIONAL);
+
+						default:
+							break;
+					}
+				}
+
+				gKeyBeingHeld = false;
+			}
+		}
+		else
+		{
+			gDebounceCounter = 0;
+			gKeyReading0     = Key;
+		}
+
+#ifdef ENABLE_UART
+		if (UART_IsCommandAvailable())
+		{
+			__disable_irq();
+			UART_HandleCommand();
+			__enable_irq();
+		}
+#endif
+		if (gUpdateDisplay)
+		{
+			Render();
+			gUpdateDisplay = false;
+		}
+	}
+}
+
+#endif