title: How to call the static function from another c file?
body: <p>I want to call a static function from another C file. But it always show <strong><code>"function" used but never defined</code></strong>.</p>
  
  <p><strong>In ble.c</strong></p>
  
  <pre><code>static void bt_le_start_notification(void)
  {
      WPRINT_BT_APP_INFO(("bt_le_start_notification\n"));
  }
  </code></pre>
  
  <p><strong>In ble.h</strong></p>
  
  <pre><code>static void bt_le_start_notification(void);
  </code></pre>
  
  <p>When I try to call <code>bt_le_start_notification</code> in <strong>main.c</strong> , it will show <strong><code>"bt_le_start_notification" used but never defined</code></strong>.</p>
  
  <p><strong>In main.c</strong></p>
  
  <pre><code>#include "ble.h"
  
  void application_start( void )
  {
    bt_le_start_notification();
  }
  </code></pre>
  
  <p>Did I missing something ? Thanks in advance.</p>