X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/782614dbb55addcae8c9d4d9e1ce3dec81287282..9da01ee78b59bcaed0d73e3f77d2f284885bfc76:/Projects/USBtoSerial/USBtoSerial.c

diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c
index fe685d6e4..fb9ac8770 100644
--- a/Projects/USBtoSerial/USBtoSerial.c
+++ b/Projects/USBtoSerial/USBtoSerial.c
@@ -1,13 +1,13 @@
 /*
              LUFA Library
-     Copyright (C) Dean Camera, 2011.
+     Copyright (C) Dean Camera, 2012.
 
   dean [at] fourwalledcubicle [dot] com
            www.lufa-lib.org
 */
 
 /*
-  Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+  Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)
 
   Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted
@@ -57,18 +57,24 @@ USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
 		.Config =
 			{
 				.ControlInterfaceNumber         = 0,
-
-				.DataINEndpointNumber           = CDC_TX_EPNUM,
-				.DataINEndpointSize             = CDC_TXRX_EPSIZE,
-				.DataINEndpointDoubleBank       = false,
-
-				.DataOUTEndpointNumber          = CDC_RX_EPNUM,
-				.DataOUTEndpointSize            = CDC_TXRX_EPSIZE,
-				.DataOUTEndpointDoubleBank      = false,
-
-				.NotificationEndpointNumber     = CDC_NOTIFICATION_EPNUM,
-				.NotificationEndpointSize       = CDC_NOTIFICATION_EPSIZE,
-				.NotificationEndpointDoubleBank = false,
+				.DataINEndpoint                 =
+					{
+						.Address                = CDC_TX_EPADDR,
+						.Size                   = CDC_TXRX_EPSIZE,
+						.Banks                  = 1,
+					},
+				.DataOUTEndpoint                =
+					{
+						.Address                = CDC_RX_EPADDR,
+						.Size                   = CDC_TXRX_EPSIZE,
+						.Banks                  = 1,
+					},
+				.NotificationEndpoint           =
+					{
+						.Address                = CDC_NOTIFICATION_EPADDR,
+						.Size                   = CDC_NOTIFICATION_EPSIZE,
+						.Banks                  = 1,
+					},
 			},
 	};
 
@@ -84,7 +90,7 @@ int main(void)
 	RingBuffer_InitBuffer(&USARTtoUSB_Buffer, USARTtoUSB_Buffer_Data, sizeof(USARTtoUSB_Buffer_Data));
 
 	LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
-	sei();
+	GlobalInterruptEnable();
 
 	for (;;)
 	{
@@ -97,26 +103,37 @@ int main(void)
 			if (!(ReceivedByte < 0))
 			  RingBuffer_Insert(&USBtoUSART_Buffer, ReceivedByte);
 		}
-		
+
 		/* Check if the UART receive buffer flush timer has expired or the buffer is nearly full */
 		uint16_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);
-		if ((TIFR0 & (1 << TOV0)) || (BufferCount > 200))
+		if ((TIFR0 & (1 << TOV0)) || (BufferCount > (uint8_t)(sizeof(USARTtoUSB_Buffer_Data) * .75)))
 		{
-			/* Clear flush timer expiry flag */
-			TIFR0 |= (1 << TOV0);
-
-			/* Read bytes from the USART receive buffer into the USB IN endpoint */
-			while (BufferCount--)
+			Endpoint_SelectEndpoint(VirtualSerial_CDC_Interface.Config.DataINEndpoint.Address);
+			
+			/* Check if a packet is already enqueued to the host - if so, we shouldn't try to send more data
+			 * until it completes as there is a chance nothing is listening and a lengthy timeout could occur */
+			if (Endpoint_IsINReady())
 			{
-				/* Try to send the next byte of data to the host, abort if there is an error without dequeuing */
-				if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
-				                        RingBuffer_Peek(&USARTtoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
+				/* Clear flush timer expiry flag */
+				TIFR0 |= (1 << TOV0);
+			
+				/* Never send more than one bank size less one byte to the host at a time, so that we don't block
+				 * while a Zero Length Packet (ZLP) to terminate the transfer is sent if the host isn't listening */
+				uint8_t BytesToSend = MIN(BufferCount, (CDC_TXRX_EPSIZE - 1));
+
+				/* Read bytes from the USART receive buffer into the USB IN endpoint */
+				while (BytesToSend--)
 				{
-					break;
+					/* Try to send the next byte of data to the host, abort if there is an error without dequeuing */
+					if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
+											RingBuffer_Peek(&USARTtoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
+					{
+						break;
+					}
+
+					/* Dequeue the already sent byte from the buffer now we have confirmed that no transmission error occurred */
+					RingBuffer_Remove(&USARTtoUSB_Buffer);
 				}
-
-				/* Dequeue the already sent byte from the buffer now we have confirmed that no transmission error occurred */
-				RingBuffer_Remove(&USARTtoUSB_Buffer);
 			}
 		}