Projects/Magstripe/Magstripe.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Denver Gingerich (denver [at] ossguy [dot] com)
  11   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  12
  13   Permission to use, copy, modify, and distribute this software
  14   and its documentation for any purpose and without fee is hereby
  15   granted, provided that the above copyright notice appear in all
  16   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 MagStripe reader program. This file contains the main tasks of
  35  *  the project and is responsible for the initial application hardware configuration.
  36  */
  37
  38 #include "Magstripe.h"
  39
  40 /** Bit buffers to hold the read bits for each of the three magnetic card tracks before they are transmitted
  41  *  to the host as keyboard presses.
  42  */
  43 BitBuffer_t TrackDataBuffers[3];
  44
  45 /** LUFA HID Class driver interface configuration and state information. This structure is
  46  *  passed to all HID 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_HID_Device_t Keyboard_HID_Interface =
  50         {
  51                 .Config =
  52                         {
  53                                 .InterfaceNumber         = 0,
  54
  55                                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  56                                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  57
  58                                 .ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
  59                         },
  60
  61                 .State =
  62                         {
  63                                 // Leave all state values to their defaults
  64                         }
  65         };
  66
  67 /** Main program entry point. This routine contains the overall program flow, including initial
  68  *  setup of all components and the main program loop.
  69  */
  70 int main(void)
  71 {
  72         SetupHardware();
  73
  74         for (uint8_t Buffer = 0; Buffer < 3; Buffer++)
  75           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  76
  77         for (;;)
  78         {
  79                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  80                   ReadMagstripeData();
  81
  82                 HID_Device_USBTask(&Keyboard_HID_Interface);
  83                 USB_USBTask();
  84         }
  85 }
  86
  87 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  88 void SetupHardware(void)
  89 {
  90         /* Disable watchdog if enabled by bootloader/fuses */
  91         MCUSR &= ~(1 << WDRF);
  92         wdt_disable();
  93
  94         /* Disable clock division */
  95         clock_prescale_set(clock_div_1);
  96
  97         /* Hardware Initialization */
  98         Magstripe_Init();
  99         USB_Init();
 100
 101         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
 102         OCR0A  = ((F_CPU / 64) / 1000);
 103         TCCR0A = (1 << WGM01);
 104         TCCR0B = ((1 << CS01) | (1 << CS00));
 105         TIMSK0 = (1 << OCIE0A);
 106 }
 107
 108 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 109  *  until they are read out to the host as a series of keyboard presses.
 110  */
 111 void ReadMagstripeData(void)
 112 {
 113         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 114         const struct
 115         {
 116                 uint8_t ClockMask;
 117                 uint8_t DataMask;
 118         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 119                          {MAG_T2_CLOCK, MAG_T2_DATA},
 120                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 121
 122         uint8_t Magstripe_Prev = 0;
 123         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 124
 125         while (Magstripe_LCL & MAG_CARDPRESENT)
 126         {
 127                 for (uint8_t Track = 0; Track < 3; Track++)
 128                 {
 129                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 130                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 131                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 132
 133                         if (ClockPinLevel && ClockLevelChanged)
 134                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 135                 }
 136
 137                 Magstripe_Prev = Magstripe_LCL;
 138                 Magstripe_LCL  = Magstripe_GetStatus();
 139         }
 140 }
 141
 142 /** Event handler for the library USB Configuration Changed event. */
 143 void EVENT_USB_ConfigurationChanged(void)
 144 {
 145         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 146 }
 147
 148 /** Event handler for the library USB Unhandled Control Packet event. */
 149 void EVENT_USB_UnhandledControlPacket(void)
 150 {
 151         HID_Device_ProcessControlPacket(&Keyboard_HID_Interface);
 152 }
 153
 154 /** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */
 155 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 156 {
 157         if (Keyboard_HID_Interface.State.IdleMSRemaining)
 158           Keyboard_HID_Interface.State.IdleMSRemaining--;
 159 }
 160
 161 /** HID Class driver callback function for the creation of a HID report for the host.
 162  *
 163  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 164  *  \param[in,out] ReportID      Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 165  *  \param[out] ReportData       Pointer to the preallocated report buffer where the created report should be stored
 166  *
 167  *  \return Number of bytes in the created report
 168  */
 169 uint16_t CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID, void* ReportData)
 170 {
 171         static bool IsKeyReleaseReport;
 172         static bool IsNewlineReport;
 173
 174         BitBuffer_t*               Buffer         = NULL;
 175         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 176
 177         /* Key reports must be interleaved with 0 Key Code reports to release the keys, or repeated keys will be ignored */
 178         IsKeyReleaseReport = !IsKeyReleaseReport;
 179
 180         if (IsKeyReleaseReport)
 181         {
 182                 KeyboardReport->KeyCode = 0;
 183         }
 184         else if (IsNewlineReport)
 185         {
 186                 IsNewlineReport = false;
 187                 KeyboardReport->KeyCode = KEY_ENTER;
 188         }
 189         else
 190         {
 191                 if (TrackDataBuffers[0].Elements)
 192                   Buffer = &TrackDataBuffers[0];
 193                 else if (TrackDataBuffers[1].Elements)
 194                   Buffer = &TrackDataBuffers[1];
 195                 else if (TrackDataBuffers[2].Elements)
 196                   Buffer = &TrackDataBuffers[2];
 197                 else
 198                   return 0;
 199
 200                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(Buffer) ? KEY_1 : KEY_0;
 201
 202                 /* If buffer now empty, next report must be a newline to seperate track data */
 203                 if (!(Buffer->Elements))
 204                   IsNewlineReport = true;
 205         }
 206
 207         return sizeof(USB_KeyboardReport_Data_t);
 208 }
 209
 210 /** HID Class driver callback function for the processing of a received HID report from the host.
 211  *
 212  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 213  *  \param[in] ReportID          Report ID of the received report from the host
 214  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 215  *  \param[in] ReportSize        Size in bytes of the report received from the host
 216  */
 217 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 218                                           const void* ReportData, const uint16_t ReportSize)
 219 {
 220         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 221 }