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/RTOS2/RTX/Template/MsgQueue.c

@@ -0,0 +1,64 @@
+#include "cmsis_os2.h"                          // CMSIS RTOS header file
+ 
+/*----------------------------------------------------------------------------
+ *      Message Queue creation & usage
+ *---------------------------------------------------------------------------*/
+ 
+#define MSGQUEUE_OBJECTS 16                     // number of Message Queue Objects
+ 
+typedef struct {                                // object data type
+  uint8_t Buf[32];
+  uint8_t Idx;
+} MSGQUEUE_OBJ_t;
+ 
+osMessageQueueId_t mid_MsgQueue;                // message queue id
+ 
+osThreadId_t tid_Thread_MsgQueue1;              // thread id 1
+osThreadId_t tid_Thread_MsgQueue2;              // thread id 2
+ 
+void Thread_MsgQueue1 (void *argument);         // thread function 1
+void Thread_MsgQueue2 (void *argument);         // thread function 2
+ 
+int Init_MsgQueue (void) {
+ 
+  mid_MsgQueue = osMessageQueueNew(MSGQUEUE_OBJECTS, sizeof(MSGQUEUE_OBJ_t), NULL);
+  if (mid_MsgQueue == NULL) {
+    ; // Message Queue object not created, handle failure
+  }
+ 
+  tid_Thread_MsgQueue1 = osThreadNew(Thread_MsgQueue1, NULL, NULL);
+  if (tid_Thread_MsgQueue1 == NULL) {
+    return(-1);
+  }
+  tid_Thread_MsgQueue2 = osThreadNew(Thread_MsgQueue2, NULL, NULL);
+  if (tid_Thread_MsgQueue2 == NULL) {
+    return(-1);
+  }
+ 
+  return(0);
+}
+ 
+void Thread_MsgQueue1 (void *argument) {
+  MSGQUEUE_OBJ_t msg;
+ 
+  while (1) {
+    ; // Insert thread code here...
+    msg.Buf[0] = 0x55U;                                         // do some work...
+    msg.Idx    = 0U;
+    osMessageQueuePut(mid_MsgQueue, &msg, 0U, 0U);
+    osThreadYield();                                            // suspend thread
+  }
+}
+ 
+void Thread_MsgQueue2 (void *argument) {
+  MSGQUEUE_OBJ_t msg;
+  osStatus_t status;
+
+  while (1) {
+    ; // Insert thread code here...
+    status = osMessageQueueGet(mid_MsgQueue, &msg, NULL, 0U);   // wait for message
+    if (status == osOK) {
+      ; // process data
+    }
+  }
+}