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/CMSIS/DAP/Firmware/Examples/MCU-LINK/README.md

@@ -0,0 +1,13 @@
+CMSIS-DAP v2 firmware for NXP MCU-LINK debug probe.
+
+CMSIS-DAP v2 uses USB bulk endpoints for the communication with the host PC and is therefore faster.
+Optionally, support for streaming SWO trace is provided via an additional USB endpoint.
+
+Instructions for programing CMSIS_DAP firmware on MCU-LINK:
+- download and install MCU-LINK_installer from https://www.nxp.com/design/microcontrollers-developer-resources/mcu-link-debug-probe:MCU-LINK
+- disconnect MCU-LINK from USB (J1), set "firmware update" jumper (J3), connect MCU-LINK to USB (J1)
+- open a Command Window
+- navigate to the MCU-LINK_installer installation (default C:\nxp\MCU-LINK_installer\) and go to the scripts sub-directory
+- copy pre-built firmware hex file ..\CMSIS\DAP\Firmware\Examples\MCU-LINK\Objects\CMSIS_DAP.hex to scripts directory
+- run the command: programm_CMSIS.cmd CMSIS_DAP.hex
+- follow the instructions in command window