void sendUSBtoUSART ()
{
if (Serial_IsSendReady() && !(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
{
Serial_SendByte(RingBuffer_Remove(&USBtoUSART_Buffer));
}
}
/** Main program entry point. This routine contains the overall program flow, including initial
* setup of all components and the main program loop.
*/
int main(void)
{
SetupHardware();
RingBuffer_InitBuffer(&USBtoUSART_Buffer, USBtoUSART_Buffer_Data, sizeof(USBtoUSART_Buffer_Data));
RingBuffer_InitBuffer(&USARTtoUSB_Buffer, USARTtoUSB_Buffer_Data, sizeof(USARTtoUSB_Buffer_Data));
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
GlobalInterruptEnable();
for (;;)
{
/* Only try to read in bytes from the CDC interface if the transmit buffer is not full */
if (!(RingBuffer_IsFull(&USBtoUSART_Buffer)))
{
int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
/* Store received byte into the USART transmit buffer */
if (!(ReceivedByte < 0))
RingBuffer_Insert(&USBtoUSART_Buffer, ReceivedByte);
}
uint16_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);
if (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())
{
/* 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--)
{
/* 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 if transmit buffer space is available */
if (Serial_IsSendReady() && !(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
Serial_SendByte(RingBuffer_Remove(&USBtoUSART_Buffer));
CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
USB_USBTask();
}
}
