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                 int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
  86                 if (!(ReceivedByte < 0) && !(RingBuffer_IsFull(&USBtoUSART_Buffer)))
  87                   RingBuffer_AtomicInsert(&USBtoUSART_Buffer, (uint8_t)ReceivedByte);
  88
  89                 /* Check if the software USART flush timer has expired */
  90                 if (TIFR0 & (1 << TOV0))
  91                 {
  92                         TIFR0 |= (1 << TOV0);
  93
  94                         /* Read bytes from the USART receive buffer into the USB IN endpoint */
  95                         while (USARTtoUSB_Buffer.Count)
  96                           CDC_Device_SendByte(&VirtualSerial_CDC_Interface, RingBuffer_AtomicRemove(&USARTtoUSB_Buffer));
  97                 }
  98
  99                 /* Load the next byte from the USART transmit buffer into the USART */
 100                 if (USBtoUSART_Buffer.Count)
 101                   Serial_TxByte(RingBuffer_AtomicRemove(&USBtoUSART_Buffer));
 102
 103                 CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
 104                 USB_USBTask();
 105         }
 106 }
 107
 108 /** Configures the board hardware and chip peripherals for the demo's functionality. */
 109 void SetupHardware(void)
 110 {
 111         /* Disable watchdog if enabled by bootloader/fuses */
 112         MCUSR &= ~(1 << WDRF);
 113         wdt_disable();
 114
 115         /* Disable clock division */
 116         clock_prescale_set(clock_div_1);
 117
 118         /* Hardware Initialization */
 119         LEDs_Init();
 120         USB_Init();
 121
 122         /* Start the flush timer so that overflows occur rapidly to push received bytes to the USB interface */
 123         TCCR0B = (1 << CS02);
 124 }
 125
 126 /** Event handler for the library USB Connection event. */
 127 void EVENT_USB_Device_Connect(void)
 128 {
 129         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 130 }
 131
 132 /** Event handler for the library USB Disconnection event. */
 133 void EVENT_USB_Device_Disconnect(void)
 134 {
 135         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 136 }
 137
 138 /** Event handler for the library USB Configuration Changed event. */
 139 void EVENT_USB_Device_ConfigurationChanged(void)
 140 {
 141         LEDs_SetAllLEDs(LEDMASK_USB_READY);
 142
 143         if (!(CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface)))
 144           LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
 145 }
 146
 147 /** Event handler for the library USB Unhandled Control Request event. */
 148 void EVENT_USB_Device_UnhandledControlRequest(void)
 149 {
 150         CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
 151 }
 152
 153 /** ISR to manage the reception of data from the serial port, placing received bytes into a circular buffer
 154  *  for later transmission to the host.
 155  */
 156 ISR(USART1_RX_vect, ISR_BLOCK)
 157 {
 158         uint8_t ReceivedByte = UDR1;
 159
 160         if (USB_DeviceState == DEVICE_STATE_Configured)
 161           RingBuffer_Insert(&USARTtoUSB_Buffer, ReceivedByte);
 162 }
 163
 164 /** Event handler for the CDC Class driver Line Encoding Changed event.
 165  *
 166  *  \param[in] CDCInterfaceInfo  Pointer to the CDC class interface configuration structure being referenced
 167  */
 168 void EVENT_CDC_Device_LineEncodingChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)
 169 {
 170         uint8_t ConfigMask = 0;
 171
 172         switch (CDCInterfaceInfo->State.LineEncoding.ParityType)
 173         {
 174                 case CDC_PARITY_Odd:
 175                         ConfigMask = ((1 << UPM11) | (1 << UPM10));
 176                         break;
 177                 case CDC_PARITY_Even:
 178                         ConfigMask = (1 << UPM11);
 179                         break;
 180         }
 181
 182         if (CDCInterfaceInfo->State.LineEncoding.CharFormat == CDC_LINEENCODING_TwoStopBits)
 183           ConfigMask |= (1 << USBS1);
 184
 185         switch (CDCInterfaceInfo->State.LineEncoding.DataBits)
 186         {
 187                 case 6:
 188                         ConfigMask |= (1 << UCSZ10);
 189                         break;
 190                 case 7:
 191                         ConfigMask |= (1 << UCSZ11);
 192                         break;
 193                 case 8:
 194                         ConfigMask |= ((1 << UCSZ11) | (1 << UCSZ10));
 195                         break;
 196         }
 197
 198         /* Must turn off USART before reconfiguring it, otherwise incorrect operation may occur */
 199         UCSR1B = 0;
 200         UCSR1A = 0;
 201         UCSR1C = 0;
 202
 203         /* Set the new baud rate before configuring the USART */
 204         UBRR1  = SERIAL_2X_UBBRVAL(CDCInterfaceInfo->State.LineEncoding.BaudRateBPS);
 205
 206         /* Reconfigure the USART in double speed mode for a wider baud rate range at the expense of accuracy */
 207         UCSR1C = ConfigMask;
 208         UCSR1A = (1 << U2X1);
 209         UCSR1B = ((1 << RXCIE1) | (1 << TXEN1) | (1 << RXEN1));
 210 }