X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/fb76acb0844a2528c32610455a8c7cd5266f3027..ec537fd84d6ad3fd0dfa1b55efa2c2d554c1db48:/Projects/USBtoSerial/USBtoSerial.c

diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c
index 7f3474af8..477dd44f5 100644
--- a/Projects/USBtoSerial/USBtoSerial.c
+++ b/Projects/USBtoSerial/USBtoSerial.c
@@ -31,7 +31,7 @@
 /** \file
  *
  *  Main source file for the USBtoSerial project. This file contains the main tasks of
- *  the demo and is responsible for the initial application hardware configuration.
+ *  the project and is responsible for the initial application hardware configuration.
  */
 
 #include "USBtoSerial.h"
@@ -100,7 +100,17 @@ int main(void)
 
 			/* Read bytes from the USART receive buffer into the USB IN endpoint */
 			while (BufferCount--)
-			  CDC_Device_SendByte(&VirtualSerial_CDC_Interface, RingBuffer_Remove(&USARTtoUSB_Buffer));
+			{
+				/* 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);
+			}
 		}
 
 		/* Load the next byte from the USART transmit buffer into the USART */