Removed code to zero reports between two keyboard reports with differing number of pressed keys, as this relied on non-standard OS behaviour.

Demos/Device/ClassDriver/Keyboard/Keyboard.c

@@ -144,7 +144,6 @@ bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDIn
 	uint8_t JoyStatus_LCL    = Joystick_GetStatus();
 	uint8_t ButtonStatus_LCL = Buttons_GetStatus();
 
-	static uint8_t PrevUsedKeyCodes;
 	uint8_t UsedKeyCodes = 0;
 	
 	if (JoyStatus_LCL & JOY_UP)
@@ -162,15 +161,6 @@ bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDIn
 	  
 	if (ButtonStatus_LCL & BUTTONS_BUTTON1)
 	  KeyboardReport->KeyCode[UsedKeyCodes++] = 0x09; // F
-	
-	/* The host will ignore the device if we add a new keycode to the report while another keycode is currently
-	 * being sent (i.e. the user has pressed another key while a key is already being pressed) - we need to intersperse
-	 * the two reports with a zeroed report to force the host to accept the additional keys */
-	if (UsedKeyCodes != PrevUsedKeyCodes)
-	{
-		memset(KeyboardReport, sizeof(USB_KeyboardReport_Data_t), 0x00);
-		PrevUsedKeyCodes = UsedKeyCodes;
-	}
 
 	*ReportSize = sizeof(USB_KeyboardReport_Data_t);
 	return false;

Demos/Device/LowLevel/Keyboard/Keyboard.c

@@ -258,11 +258,11 @@ void EVENT_USB_Device_StartOfFrame(void)
  */
 void CreateKeyboardReport(USB_KeyboardReport_Data_t* ReportData)
 {
-	static uint8_t PrevUsedKeyCodes;
-	uint8_t UsedKeyCodes      = 0;
 	uint8_t JoyStatus_LCL     = Joystick_GetStatus();
 	uint8_t ButtonStatus_LCL  = Buttons_GetStatus();
 
+	uint8_t UsedKeyCodes      = 0;
+
 	/* Clear the report contents */
 	memset(ReportData, 0, sizeof(USB_KeyboardReport_Data_t));
 	
@@ -281,15 +281,6 @@ void CreateKeyboardReport(USB_KeyboardReport_Data_t* ReportData)
 	  
 	if (ButtonStatus_LCL & BUTTONS_BUTTON1)
 	  ReportData->KeyCode[UsedKeyCodes++] = 0x09; // F
-	
-	/* The host will ignore the device if we add a new keycode to the report while another keycode is currently
-	 * being sent (i.e. the user has pressed another key while a key is already being pressed) - we need to intersperse
-	 * the two reports with a zeroed report to force the host to accept the additional keys */
-	if (UsedKeyCodes != PrevUsedKeyCodes)
-	{
-		memset(ReportData, 0, sizeof(USB_KeyboardReport_Data_t));
-		PrevUsedKeyCodes = UsedKeyCodes;
-	}
 }
 
 /** Processes a received LED report, and updates the board LEDs states to match.

LUFA/ManPages/ChangeLog.txt

@@ -8,7 +8,12 @@
   *
   *  \section Sec_ChangeLogXXXXXX Version XXXXXX
   *
-  *  <b>There is no changelog information for this version.</b>
+  *  <b>New:</b>
+  *  - Added activity LED indicators to the AVRISP project to indicate when the device is busy processing a command
+  *
+  *  <b>Changed:</b>
+  *  - Removed code in the Keyboard demos to send zeroed reports between two reports with differing numbers of keycodes
+  *    as this relied on non-standard OS driver behaviour to repeat key groups
   *
   *  \section Sec_ChangeLog091122 Version 091122
   *