Projects/SerialToLCD/SerialToLCD.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2012.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11   Copyright 2012  Simon Foster (simon.foster [at] inbox [dot] com)
  12
  13   Permission to use, copy, modify, distribute, and sell this
  14   software and its documentation for any purpose is hereby granted
  15   without fee, provided that the above copyright notice appear in
  16   all copies and that both that the copyright notice and this
  17   permission notice and warranty disclaimer appear in supporting
  18   documentation, and that the name of the author not be used in
  19   advertising or publicity pertaining to distribution of the
  20   software without specific, written prior permission.
  21
  22   The author disclaim all warranties with regard to this
  23   software, including all implied warranties of merchantability
  24   and fitness.  In no event shall the author be liable for any
  25   special, indirect or consequential damages or any damages
  26   whatsoever resulting from loss of use, data or profits, whether
  27   in an action of contract, negligence or other tortious action,
  28   arising out of or in connection with the use or performance of
  29   this software.
  30 */
  31
  32 /** \file
  33  *
  34  *  Main source file for the SerialToLCD program. This file contains the main tasks of
  35  *  the project and is responsible for the initial application hardware configuration.
  36  *
  37  *  \section Hardware Information
  38  *
  39  *    LCD Datasheet:  See http://www.sparkfun.com/datasheets/LCD/HD44780.pdf
  40  *
  41  *   Also see the two articles from EPE which are linked from here:
  42  *   http://en.wikipedia.org/wiki/HD44780_Character_LCD
  43  *
  44  *   Connections from the Minimus to the HD44780 as shown below.
  45  *
  46  *   =========================================================  \n
  47  *   Minimus                 HD44780     Pin                    \n
  48  *   =========================================================  \n
  49  *   PD0                     DB4         11                     \n
  50  *   PD1                     DB5         12                     \n
  51  *   PD2                     DB6         13                     \n
  52  *   PD3                     DB7         14                     \n
  53  *                                                              \n
  54  *   PD4                     RS          4                      \n
  55  *                           RW          5       GND            \n
  56  *   PD7                     EN          6                      \n
  57  *                                                              \n
  58  *                                       1       GND            \n
  59  *                                       2       USB +5V        \n
  60  *                                       3       2k -> GND      \n
  61  */
  62
  63 #include "SerialToLCD.h"
  64
  65 /** Circular buffer to hold data from the host before it is sent to the LCD */
  66 static RingBuffer_t FromHost_Buffer;
  67
  68 /** Underlying data buffer for \ref FromHost_Buffer, where the stored bytes are located. */
  69 static uint8_t      FromHost_Buffer_Data[128];
  70
  71 /** LUFA CDC Class driver interface configuration and state information. This structure is
  72  *  passed to all CDC Class driver functions, so that multiple instances of the same class
  73  *  within a device can be differentiated from one another.
  74  */
  75 USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
  76         {
  77                 .Config =
  78                         {
  79                                 .ControlInterfaceNumber   = 0,
  80                                 .DataINEndpoint           =
  81                                         {
  82                                                 .Address          = CDC_TX_EPADDR,
  83                                                 .Size             = CDC_TXRX_EPSIZE,
  84                                                 .Banks            = 1,
  85                                         },
  86                                 .DataOUTEndpoint =
  87                                         {
  88                                                 .Address          = CDC_RX_EPADDR,
  89                                                 .Size             = CDC_TXRX_EPSIZE,
  90                                                 .Banks            = 1,
  91                                         },
  92                                 .NotificationEndpoint =
  93                                         {
  94                                                 .Address          = CDC_NOTIFICATION_EPADDR,
  95                                                 .Size             = CDC_NOTIFICATION_EPSIZE,
  96                                                 .Banks            = 1,
  97                                         },
  98                         },
  99         };
 100
 101
 102 /** Main program entry point. This routine contains the overall program flow, including initial
 103  *  setup of all components and the main program loop.
 104  */
 105 int main(void)
 106 {
 107         SetupHardware();
 108
 109         RingBuffer_InitBuffer(&FromHost_Buffer, FromHost_Buffer_Data, sizeof(FromHost_Buffer_Data));
 110
 111         sei();
 112
 113         for (;;)
 114         {
 115                 /* Only try to read in bytes from the CDC interface if the transmit buffer is not full */
 116                 if (!(RingBuffer_IsFull(&FromHost_Buffer)))
 117                 {
 118                         int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
 119
 120                         /* Read bytes from the USB OUT endpoint into the USART transmit buffer */
 121                         if (!(ReceivedByte < 0))
 122                           RingBuffer_Insert(&FromHost_Buffer, ReceivedByte);
 123                 }
 124
 125                 while (RingBuffer_GetCount(&FromHost_Buffer) > 0)
 126                 {
 127                         static uint8_t escape_pending = 0;
 128                         int16_t HD44780Byte = RingBuffer_Remove(&FromHost_Buffer);
 129
 130                         if (HD44780Byte == COMMAND_ESCAPE)
 131                         {
 132                                 if (escape_pending)
 133                                 {
 134                                         HD44780_WriteData(HD44780Byte);
 135                                         escape_pending = 0;
 136                                 }
 137                                 else
 138                                 {
 139                                         escape_pending = 1;
 140                                 }
 141                         }
 142                         else
 143                         {
 144                                 if (escape_pending)
 145                                 {
 146                                         HD44780_WriteCommand(HD44780Byte);
 147                                         escape_pending = 0;
 148                                 }
 149                                 else
 150                                 {
 151                                         HD44780_WriteData(HD44780Byte);
 152                                 }
 153                         }
 154                 }
 155
 156                 CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
 157                 USB_USBTask();
 158         }
 159 }
 160
 161 /** Configures the board hardware and chip peripherals for the application's functionality. */
 162 void SetupHardware(void)
 163 {
 164         /* Disable watchdog if enabled by bootloader/fuses */
 165         MCUSR &= ~(1 << WDRF);
 166         wdt_disable();
 167
 168         /* Disable clock division */
 169         clock_prescale_set(clock_div_1);
 170
 171         /* Hardware Initialization */
 172         USB_Init();
 173
 174         /* Power up the HD44780 Interface */
 175         HD44780_Initialise();
 176         HD44780_WriteCommand(CMD_DISPLAY_ON);
 177
 178         /* Start the flush timer so that overflows occur rapidly to push received bytes to the USB interface */
 179         TCCR0B = (1 << CS02);
 180 }
 181
 182 /** Event handler for the library USB Configuration Changed event. */
 183 void EVENT_USB_Device_ConfigurationChanged(void)
 184 {
 185         bool ConfigSuccess = true;
 186
 187         ConfigSuccess &= CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);
 188 }
 189
 190 /** Event handler for the library USB Control Request reception event. */
 191 void EVENT_USB_Device_ControlRequest(void)
 192 {
 193         CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
 194 }