Documentation improvements - put driver example code into its own section, fix incorr...

[pub/USBasp.git] / Projects / USBtoSerial / USBtoSerial.c

diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c
index 3f06acd..e775541 100644 (file)
--- 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
 /** \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"
  */
 
 #include "USBtoSerial.h"


@@ -39,9 +39,16 @@
 /** Circular buffer to hold data from the host before it is sent to the device via the serial port. */
 RingBuff_t USBtoUSART_Buffer;
 
 /** Circular buffer to hold data from the host before it is sent to the device via the serial port. */
 RingBuff_t USBtoUSART_Buffer;
 

+/** Underlying data buffer for \ref USBtoUSART_Buffer, where the stored bytes are located. */
+uint8_t    USBtoUSART_Buffer_Data[128];
+

 /** Circular buffer to hold data from the serial port before it is sent to the host. */
 RingBuff_t USARTtoUSB_Buffer;
 
 /** Circular buffer to hold data from the serial port before it is sent to the host. */
 RingBuff_t USARTtoUSB_Buffer;
 

+/** Underlying data buffer for \ref USARTtoUSB_Buffer, where the stored bytes are located. */
+uint8_t    USARTtoUSB_Buffer_Data[128];
+
+

 /** LUFA CDC Class driver interface configuration and state information. This structure is
  *  passed to all CDC Class driver functions, so that multiple instances of the same class
  *  within a device can be differentiated from one another.
 /** LUFA CDC Class driver interface configuration and state information. This structure is
  *  passed to all CDC Class driver functions, so that multiple instances of the same class
  *  within a device can be differentiated from one another.


@@ -73,28 +80,44 @@ int main(void)
 {
        SetupHardware();
 
 {
        SetupHardware();
 

-       RingBuffer_InitBuffer(&USBtoUSART_Buffer);
-       RingBuffer_InitBuffer(&USARTtoUSB_Buffer);
+       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);
        sei();
 
        for (;;)
        {
 
        LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
        sei();
 
        for (;;)
        {

-               /* Read bytes from the USB OUT endpoint into the USART transmit buffer */
-               int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
-               if (!(ReceivedByte < 0) && !(RingBuffer_IsFull(&USBtoUSART_Buffer)))
-                 RingBuffer_Insert(&USBtoUSART_Buffer, ReceivedByte);
+               /* 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);

 
 

+                       /* Read bytes from the USB OUT endpoint into the USART transmit buffer */
+                       if (!(ReceivedByte < 0))
+                         RingBuffer_Insert(&USBtoUSART_Buffer, ReceivedByte);
+               }
+               

                /* Check if the UART receive buffer flush timer has expired or the buffer is nearly full */
                /* Check if the UART receive buffer flush timer has expired or the buffer is nearly full */

-               RingBuff_Count_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);
+               uint16_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);

                if ((TIFR0 & (1 << TOV0)) || (BufferCount > 200))
                {
                if ((TIFR0 & (1 << TOV0)) || (BufferCount > 200))
                {

+                       /* Clear flush timer expiry flag */

                        TIFR0 |= (1 << TOV0);
 
                        /* Read bytes from the USART receive buffer into the USB IN endpoint */
                        while (BufferCount--)
                        TIFR0 |= (1 << TOV0);
 
                        /* 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 */
                }
 
                /* Load the next byte from the USART transmit buffer into the USART */


@@ -146,8 +169,8 @@ void EVENT_USB_Device_ConfigurationChanged(void)
        LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 }
 
        LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 }
 

-/** Event handler for the library USB Unhandled Control Request event. */
-void EVENT_USB_Device_UnhandledControlRequest(void)
+/** Event handler for the library USB Control Request reception event. */
+void EVENT_USB_Device_ControlRequest(void)

 {
        CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
 }
 {
        CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
 }