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/RTOS/RTX/UserCodeTemplates/MailQueue.c

@@ -0,0 +1,71 @@
+
+#include "cmsis_os.h"                                           // CMSIS RTOS header file
+
+/*----------------------------------------------------------------------------
+ *      Mail Queue creation & usage
+ *---------------------------------------------------------------------------*/
+ 
+void Thread_MailQueue1 (void const *argument);                  // thread function 1
+void Thread_MailQueue2 (void const *argument);                  // thread function 2
+osThreadId tid_Thread_MailQueue1;                               // thread id 1
+osThreadId tid_Thread_MailQueue2;                               // thread id 2
+osThreadDef (Thread_MailQueue1, osPriorityNormal, 1, 0);        // thread object 1
+osThreadDef (Thread_MailQueue2, osPriorityNormal, 1, 0);        // thread object 2
+
+#define MAILQUEUE_OBJECTS      16                               // number of Message Queue Objects
+typedef struct {                                                // object data type
+  uint8_t Buf[32];
+  uint8_t Idx;
+} MAILQUEUE_OBJ_t;
+
+osMailQId qid_MailQueue;                                        // mail queue id
+osMailQDef (MailQueue, MAILQUEUE_OBJECTS, MAILQUEUE_OBJ_t);     // mail queue object
+
+
+int Init_MailQueue (void) {
+
+  qid_MailQueue = osMailCreate (osMailQ(MailQueue), NULL);      // create mail queue
+  if (!qid_MailQueue) {
+    ; // Mail Queue object not created, handle failure
+  }
+  
+  tid_Thread_MailQueue1 = osThreadCreate (osThread(Thread_MailQueue1),  NULL);
+  if (!tid_Thread_MailQueue1) return(-1);
+  tid_Thread_MailQueue2 = osThreadCreate (osThread(Thread_MailQueue2),  NULL);
+  if (!tid_Thread_MailQueue2) return(-1);
+  
+  return(0);
+}
+
+void Thread_MailQueue1 (void const *argument) {
+  MAILQUEUE_OBJ_t *pMail = 0;
+
+  while (1) {
+    ; // Insert thread code here...
+    pMail = osMailAlloc (qid_MailQueue, osWaitForever);         // Allocate memory
+    if (pMail) {
+      pMail->Buf[0] = 0xff;                                     // Set the mail content
+      pMail->Idx = 0;
+      osMailPut (qid_MailQueue, pMail);                         // Send Mail
+    }
+
+    osThreadYield ();                                           // suspend thread
+  }
+}
+
+void Thread_MailQueue2 (void const *argument) {
+  MAILQUEUE_OBJ_t  *pMail = 0;
+  osEvent           evt;
+
+  while (1) {
+    ; // Insert thread code here...
+    evt = osMailGet (qid_MailQueue, osWaitForever);             // wait for mail
+    if (evt.status == osEventMail) {
+      pMail = evt.value.p;
+      if (pMail) {
+        ; // process data
+        osMailFree (qid_MailQueue, pMail);                      // free memory allocated for mail
+      }
+    }
+  }
+}