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 dd9a133..e775541 100644 (file)
--- a/Projects/USBtoSerial/USBtoSerial.c
+++ b/Projects/USBtoSerial/USBtoSerial.c
@@ -1,21 +1,21 @@
 /*
              LUFA Library
      Copyright (C) Dean Camera, 2010.
 /*
              LUFA Library
      Copyright (C) Dean Camera, 2010.

-              
+

   dean [at] fourwalledcubicle [dot] com
   dean [at] fourwalledcubicle [dot] com

-      www.fourwalledcubicle.com
+           www.lufa-lib.org

 */
 
 /*
   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
 
 */
 
 /*
   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
 

-  Permission to use, copy, modify, distribute, and sell this 
+  Permission to use, copy, modify, distribute, and sell this

   software and its documentation for any purpose is hereby granted
   software and its documentation for any purpose is hereby granted

-  without fee, provided that the above copyright notice appear in 
+  without fee, provided that the above copyright notice appear in

   all copies and that both that the copyright notice and this
   all copies and that both that the copyright notice and this

-  permission notice and warranty disclaimer appear in supporting 
-  documentation, and that the name of the author not be used in 
-  advertising or publicity pertaining to distribution of the 
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the

   software without specific, written prior permission.
 
   The author disclaim all warranties with regard to this
   software without specific, written prior permission.
 
   The author disclaim all warranties with regard to this


@@ -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"


@@ -39,16 +39,23 @@
 /** 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.
  */
 USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
        {
 /** 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.
  */
 USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
        {

-               .Config = 
+               .Config =

                        {
                                .ControlInterfaceNumber         = 0,
 
                        {
                                .ControlInterfaceNumber         = 0,
 


@@ -72,32 +79,51 @@ USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
 int main(void)
 {
        SetupHardware();
 int main(void)
 {
        SetupHardware();

-       
-       Buffer_Initialize(&USBtoUSART_Buffer);
-       Buffer_Initialize(&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 */
-               for (uint8_t DataBytesRem = CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface); DataBytesRem != 0; DataBytesRem--)
+               /* Only try to read in bytes from the CDC interface if the transmit buffer is not full */
+               if (!(RingBuffer_IsFull(&USBtoUSART_Buffer)))

                {
                {

-                       if (!(BUFF_STATICSIZE - USBtoUSART_Buffer.Elements))
-                         break;
-                         
-                       Buffer_StoreElement(&USBtoUSART_Buffer, CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface));
+                       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);

                }
                
                }
                

-               /* Read bytes from the USART receive buffer into the USB IN endpoint */
-               while (USARTtoUSB_Buffer.Elements)
-                 CDC_Device_SendByte(&VirtualSerial_CDC_Interface, Buffer_GetElement(&USARTtoUSB_Buffer));
-               
-               /* Load bytes from the USART transmit buffer into the USART */
-               while (USBtoUSART_Buffer.Elements)
-                 Serial_TxByte(Buffer_GetElement(&USBtoUSART_Buffer));
-               
+               /* 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))
+               {
+                       /* Clear flush timer expiry flag */
+                       TIFR0 |= (1 << TOV0);
+
+                       /* Read bytes from the USART receive buffer into the USB IN endpoint */
+                       while (BufferCount--)
+                       {
+                               /* 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 (!(RingBuffer_IsEmpty(&USBtoUSART_Buffer)))
+                 Serial_TxByte(RingBuffer_Remove(&USBtoUSART_Buffer));
+

                CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
                USB_USBTask();
        }
                CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
                USB_USBTask();
        }


@@ -114,9 +140,11 @@ void SetupHardware(void)
        clock_prescale_set(clock_div_1);
 
        /* Hardware Initialization */
        clock_prescale_set(clock_div_1);
 
        /* Hardware Initialization */

-       Serial_Init(9600, false);

        LEDs_Init();
        USB_Init();
        LEDs_Init();
        USB_Init();

+
+       /* Start the flush timer so that overflows occur rapidly to push received bytes to the USB interface */
+       TCCR0B = (1 << CS02);

 }
 
 /** Event handler for the library USB Connection event. */
 }
 
 /** Event handler for the library USB Connection event. */


@@ -134,14 +162,15 @@ void EVENT_USB_Device_Disconnect(void)
 /** Event handler for the library USB Configuration Changed event. */
 void EVENT_USB_Device_ConfigurationChanged(void)
 {
 /** Event handler for the library USB Configuration Changed event. */
 void EVENT_USB_Device_ConfigurationChanged(void)
 {

-       LEDs_SetAllLEDs(LEDMASK_USB_READY);
+       bool ConfigSuccess = true;
+
+       ConfigSuccess &= CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);

 
 

-       if (!(CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface)))
-         LEDs_SetAllLEDs(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);
 }


@@ -154,7 +183,7 @@ ISR(USART1_RX_vect, ISR_BLOCK)
        uint8_t ReceivedByte = UDR1;
 
        if (USB_DeviceState == DEVICE_STATE_Configured)
        uint8_t ReceivedByte = UDR1;
 
        if (USB_DeviceState == DEVICE_STATE_Configured)

-         Buffer_StoreElement(&USARTtoUSB_Buffer, ReceivedByte);
+         RingBuffer_Insert(&USARTtoUSB_Buffer, ReceivedByte);

 }
 
 /** Event handler for the CDC Class driver Line Encoding Changed event.
 }
 
 /** Event handler for the CDC Class driver Line Encoding Changed event.


@@ -168,10 +197,10 @@ void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCI
        switch (CDCInterfaceInfo->State.LineEncoding.ParityType)
        {
                case CDC_PARITY_Odd:
        switch (CDCInterfaceInfo->State.LineEncoding.ParityType)
        {
                case CDC_PARITY_Odd:

-                       ConfigMask = ((1 << UPM11) | (1 << UPM10));             
+                       ConfigMask = ((1 << UPM11) | (1 << UPM10));

                        break;
                case CDC_PARITY_Even:
                        break;
                case CDC_PARITY_Even:

-                       ConfigMask = (1 << UPM11);              
+                       ConfigMask = (1 << UPM11);

                        break;
        }
 
                        break;
        }
 


@@ -190,9 +219,18 @@ void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCI
                        ConfigMask |= ((1 << UCSZ11) | (1 << UCSZ10));
                        break;
        }
                        ConfigMask |= ((1 << UCSZ11) | (1 << UCSZ10));
                        break;
        }

-       
-       UCSR1A = (1 << U2X1);   
-       UCSR1B = ((1 << RXCIE1) | (1 << TXEN1) | (1 << RXEN1));
-       UCSR1C = ConfigMask;    
+
+       /* Must turn off USART before reconfiguring it, otherwise incorrect operation may occur */
+       UCSR1B = 0;
+       UCSR1A = 0;
+       UCSR1C = 0;
+
+       /* Set the new baud rate before configuring the USART */

        UBRR1  = SERIAL_2X_UBBRVAL(CDCInterfaceInfo->State.LineEncoding.BaudRateBPS);
        UBRR1  = SERIAL_2X_UBBRVAL(CDCInterfaceInfo->State.LineEncoding.BaudRateBPS);

+
+       /* Reconfigure the USART in double speed mode for a wider baud rate range at the expense of accuracy */
+       UCSR1C = ConfigMask;
+       UCSR1A = (1 << U2X1);
+       UCSR1B = ((1 << RXCIE1) | (1 << TXEN1) | (1 << RXEN1));

 }
 }

+