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)

external/CMSIS_5/.gitignore

@@ -0,0 +1,24 @@
+*.breadcrumb
+*.junit
+**/__pycache__
+Local_Release/
+CMSIS/Documentation/
+CMSIS/RTOS2/RTX/Library/ARM/MDK/RTX_CM.uvguix.*
+CMSIS/CoreValidation/Project/*.zip
+CMSIS/CoreValidation/Project/*.junit
+CMSIS/CoreValidation/Project/Validation.*/
+CMSIS/CoreValidation/Project/Bootloader.*/
+*.uvguix.*
+*.uvmpw.uvgui.*
+*.zip
+docker/dependenciesFiles
+CMSIS/RTOS/RTX/LIB/**/*.a
+CMSIS/RTOS/RTX/LIB/**/*.lib
+CMSIS/RTOS2/RTX/Library/**/*.a
+CMSIS/RTOS2/RTX/Library/**/*.lib
+output
+.DS_Store
+internal.cp310-win_amd64.pyd
+CMSIS/Utilities/Darwin64
+CMSIS/Utilities/Linux64
+CMSIS/Utilities/Win32