Projects/USBtoSerial/USBtoSerial.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Main source file for the USBtoSerial project. This file contains the main tasks of
  34  *  the demo and is responsible for the initial application hardware configuration.
  35  */
  36
  37 #include "USBtoSerial.h"
  38
  39 /** Circular buffer to hold data from the host before it is sent to the device via the serial port. */
  40 RingBuff_t USBtoUSART_Buffer;
  41
  42 /** Circular buffer to hold data from the serial port before it is sent to the host. */
  43 RingBuff_t USARTtoUSB_Buffer;
  44
  45 /** LUFA CDC Class driver interface configuration and state information. This structure is
  46  *  passed to all CDC Class driver functions, so that multiple instances of the same class
  47  *  within a device can be differentiated from one another.
  48  */
  49 USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
  50         {
  51                 .Config =
  52                         {
  53                                 .ControlInterfaceNumber         = 0,
  54
  55                                 .DataINEndpointNumber           = CDC_TX_EPNUM,
  56                                 .DataINEndpointSize             = CDC_TXRX_EPSIZE,
  57                                 .DataINEndpointDoubleBank       = false,
  58
  59                                 .DataOUTEndpointNumber          = CDC_RX_EPNUM,
  60                                 .DataOUTEndpointSize            = CDC_TXRX_EPSIZE,
  61                                 .DataOUTEndpointDoubleBank      = false,
  62
  63                                 .NotificationEndpointNumber     = CDC_NOTIFICATION_EPNUM,
  64                                 .NotificationEndpointSize       = CDC_NOTIFICATION_EPSIZE,
  65                                 .NotificationEndpointDoubleBank = false,
  66                         },
  67         };
  68
  69 /** Main program entry point. This routine contains the overall program flow, including initial
  70  *  setup of all components and the main program loop.
  71  */
  72 int main(void)
  73 {
  74         SetupHardware();
  75
  76         RingBuffer_InitBuffer(&USBtoUSART_Buffer);
  77         RingBuffer_InitBuffer(&USARTtoUSB_Buffer);
  78
  79         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  80         sei();
  81
  82         for (;;)
  83         {
  84                 /* Read bytes from the USB OUT endpoint into the USART transmit buffer */
  85                 for (uint8_t DataBytesRem = CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface); DataBytesRem != 0; DataBytesRem--)
  86                 {
  87                         if (RingBuffer_IsFull(&USBtoUSART_Buffer))
  88                           break;
  89
  90                         RingBuffer_AtomicInsert(&USBtoUSART_Buffer, CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface));
  91                 }
  92
  93                 /* Check if the software USART flush timer has expired */
  94                 if (TIFR0 & (1 << TOV0))
  95                 {
  96                         TIFR0 |= (1 << TOV0);
  97
  98                         /* Read bytes from the USART receive buffer into the USB IN endpoint */
  99                         while (USARTtoUSB_Buffer.Count)
 100                           CDC_Device_SendByte(&VirtualSerial_CDC_Interface, RingBuffer_AtomicRemove(&USARTtoUSB_Buffer));
 101                 }
 102
 103                 /* Load the next byte from the USART transmit buffer into the USART */
 104                 if (USBtoUSART_Buffer.Count)
 105                   Serial_TxByte(RingBuffer_AtomicRemove(&USBtoUSART_Buffer));
 106
 107                 CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
 108                 USB_USBTask();
 109         }
 110 }
 111
 112 /** Configures the board hardware and chip peripherals for the demo's functionality. */
 113 void SetupHardware(void)
 114 {
 115         /* Disable watchdog if enabled by bootloader/fuses */
 116         MCUSR &= ~(1 << WDRF);
 117         wdt_disable();
 118
 119         /* Disable clock division */
 120         clock_prescale_set(clock_div_1);
 121
 122         /* Hardware Initialization */
 123         LEDs_Init();
 124         USB_Init();
 125
 126         /* Start the flush timer so that overflows occur rapidly to push received bytes to the USB interface */
 127         TCCR0B = (1 << CS02);
 128 }
 129
 130 /** Event handler for the library USB Connection event. */
 131 void EVENT_USB_Device_Connect(void)
 132 {
 133         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 134 }
 135
 136 /** Event handler for the library USB Disconnection event. */
 137 void EVENT_USB_Device_Disconnect(void)
 138 {
 139         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 140 }
 141
 142 /** Event handler for the library USB Configuration Changed event. */
 143 void EVENT_USB_Device_ConfigurationChanged(void)
 144 {
 145         LEDs_SetAllLEDs(LEDMASK_USB_READY);
 146
 147         if (!(CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface)))
 148           LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
 149 }
 150
 151 /** Event handler for the library USB Unhandled Control Request event. */
 152 void EVENT_USB_Device_UnhandledControlRequest(void)
 153 {
 154         CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
 155 }
 156
 157 /** ISR to manage the reception of data from the serial port, placing received bytes into a circular buffer
 158  *  for later transmission to the host.
 159  */
 160 ISR(USART1_RX_vect, ISR_BLOCK)
 161 {
 162         uint8_t ReceivedByte = UDR1;
 163
 164         if (USB_DeviceState == DEVICE_STATE_Configured)
 165           RingBuffer_Insert(&USARTtoUSB_Buffer, ReceivedByte);
 166 }
 167
 168 /** Event handler for the CDC Class driver Line Encoding Changed event.
 169  *
 170  *  \param[in] CDCInterfaceInfo  Pointer to the CDC class interface configuration structure being referenced
 171  */
 172 void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)
 173 {
 174         uint8_t ConfigMask = 0;
 175
 176         switch (CDCInterfaceInfo->State.LineEncoding.ParityType)
 177         {
 178                 case CDC_PARITY_Odd:
 179                         ConfigMask = ((1 << UPM11) | (1 << UPM10));
 180                         break;
 181                 case CDC_PARITY_Even:
 182                         ConfigMask = (1 << UPM11);
 183                         break;
 184         }
 185
 186         if (CDCInterfaceInfo->State.LineEncoding.CharFormat == CDC_LINEENCODING_TwoStopBits)
 187           ConfigMask |= (1 << USBS1);
 188
 189         switch (CDCInterfaceInfo->State.LineEncoding.DataBits)
 190         {
 191                 case 6:
 192                         ConfigMask |= (1 << UCSZ10);
 193                         break;
 194                 case 7:
 195                         ConfigMask |= (1 << UCSZ11);
 196                         break;
 197                 case 8:
 198                         ConfigMask |= ((1 << UCSZ11) | (1 << UCSZ10));
 199                         break;
 200         }
 201
 202         /* Must turn off USART before reconfiguring it, otherwise incorrect operation may occur */
 203         UCSR1B = 0;
 204         UCSR1A = 0;
 205         UCSR1C = 0;
 206
 207         /* Set the new baud rate before configuring the USART */
 208         UBRR1  = SERIAL_2X_UBBRVAL(CDCInterfaceInfo->State.LineEncoding.BaudRateBPS);
 209
 210         /* Reconfigure the USART in double speed mode for a wider baud rate range at the expense of accuracy */
 211         UCSR1C = ConfigMask;
 212         UCSR1A = (1 << U2X1);
 213         UCSR1B = ((1 << RXCIE1) | (1 << TXEN1) | (1 << RXEN1));
 214 }