- /* Read bytes from the USB OUT endpoint into the UART transmit buffer */
- int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
- if (!(ReceivedByte < 0) && !(RingBuffer_IsFull(&USBtoUART_Buffer)))
- RingBuffer_AtomicInsert(&USBtoUART_Buffer, CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface));
-
- /* Check if the UART receive buffer flush timer has expired */
- if (TIFR0 & (1 << TOV0))
+ /* Only try to read in bytes from the CDC interface if the transmit buffer is not full */
+ if (!(RingBuffer_IsFull(&USBtoUART_Buffer)))
+ {
+ int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
+
+ /* Read bytes from the USB OUT endpoint into the UART transmit buffer */
+ if (!(ReceivedByte < 0))
+ RingBuffer_Insert(&USBtoUART_Buffer, ReceivedByte);
+ }
+
+ /* Check if the UART receive buffer flush timer has expired or buffer is nearly full */
+ uint16_t BufferCount = RingBuffer_GetCount(&UARTtoUSB_Buffer);
+ if ((TIFR0 & (1 << TOV0)) || (BufferCount > 200))