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[TOTAL_TRACKS];
  44
  45 /** Pointer to the current track buffer being sent to the host. */
  46 BitBuffer_t* CurrentTrackBuffer = &TrackDataBuffers[TOTAL_TRACKS];
  47
  48 /** LUFA HID Class driver interface configuration and state information. This structure is
  49  *  passed to all HID Class driver functions, so that multiple instances of the same class
  50  *  within a device can be differentiated from one another.
  51  */
  52 USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
  53         {
  54                 .Config =
  55                         {
  56                                 .InterfaceNumber         = 0,
  57
  58                                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  59                                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  60                         },
  61         };
  62
  63 /** Main program entry point. This routine contains the overall program flow, including initial
  64  *  setup of all components and the main program loop.
  65  */
  66 int main(void)
  67 {
  68         SetupHardware();
  69
  70         for (uint8_t Buffer = 0; Buffer < TOTAL_TRACKS; Buffer++)
  71           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  72
  73         for (;;)
  74         {
  75                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  76                   ReadMagstripeData();
  77
  78                 HID_Device_USBTask(&Keyboard_HID_Interface);
  79                 USB_USBTask();
  80         }
  81 }
  82
  83 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  84 void SetupHardware(void)
  85 {
  86         /* Disable watchdog if enabled by bootloader/fuses */
  87         MCUSR &= ~(1 << WDRF);
  88         wdt_disable();
  89
  90         /* Disable clock division */
  91         clock_prescale_set(clock_div_1);
  92
  93         /* Hardware Initialization */
  94         Magstripe_Init();
  95         USB_Init();
  96
  97         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
  98         OCR0A  = ((F_CPU / 64) / 1000);
  99         TCCR0A = (1 << WGM01);
 100         TCCR0B = ((1 << CS01) | (1 << CS00));
 101         TIMSK0 = (1 << OCIE0A);
 102 }
 103
 104 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 105  *  until they are read out to the host as a series of keyboard presses.
 106  */
 107 void ReadMagstripeData(void)
 108 {
 109         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 110         const struct
 111         {
 112                 uint8_t ClockMask;
 113                 uint8_t DataMask;
 114         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 115                          {MAG_T2_CLOCK, MAG_T2_DATA},
 116                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 117
 118         uint8_t Magstripe_Prev = 0;
 119         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 120
 121         while (Magstripe_LCL & MAG_CARDPRESENT)
 122         {
 123                 for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)
 124                 {
 125                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 126                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 127                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 128
 129                         /* Sample data on rising clock edges from the card reader */
 130                         if (ClockPinLevel && ClockLevelChanged)
 131                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 132                 }
 133
 134                 Magstripe_Prev = Magstripe_LCL;
 135                 Magstripe_LCL  = Magstripe_GetStatus();
 136         }
 137
 138         CurrentTrackBuffer = &TrackDataBuffers[0];
 139 }
 140
 141 /** Event handler for the library USB Configuration Changed event. */
 142 void EVENT_USB_ConfigurationChanged(void)
 143 {
 144         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 145 }
 146
 147 /** Event handler for the library USB Unhandled Control Packet event. */
 148 void EVENT_USB_UnhandledControlPacket(void)
 149 {
 150         HID_Device_ProcessControlPacket(&Keyboard_HID_Interface);
 151 }
 152
 153 /** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */
 154 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 155 {
 156         HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);
 157 }
 158
 159 /** HID Class driver callback function for the creation of a HID report for the host.
 160  *
 161  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 162  *  \param[in,out] ReportID      Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 163  *  \param[out] ReportData       Pointer to the preallocated report buffer where the created report should be stored
 164  *
 165  *  \return Number of bytes in the created report
 166  */
 167 uint16_t CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID, void* ReportData)
 168 {
 169         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 170
 171         static bool IsKeyReleaseReport;
 172
 173         /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */
 174         IsKeyReleaseReport = !IsKeyReleaseReport;
 175
 176         if ((IsKeyReleaseReport) || (CurrentTrackBuffer == &TrackDataBuffers[TOTAL_TRACKS]))
 177         {
 178                 /* No more data to send, or key release report between key presses */
 179                 KeyboardReport->KeyCode = KEY_NONE;
 180         }
 181         else if (!(CurrentTrackBuffer->Elements))
 182         {
 183                 /* End of current track, send an enter press and change to the next track's buffer */
 184                 KeyboardReport->KeyCode = KEY_ENTER;
 185                 CurrentTrackBuffer++;
 186         }
 187         else
 188         {
 189                 /* Still data in the current track; convert next bit to a 1 or 0 keypress */
 190                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(CurrentTrackBuffer) ? KEY_1 : KEY_0;
 191         }
 192
 193         return sizeof(USB_KeyboardReport_Data_t);
 194 }
 195
 196 /** HID Class driver callback function for the processing of a received HID report from the host.
 197  *
 198  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 199  *  \param[in] ReportID          Report ID of the received report from the host
 200  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 201  *  \param[in] ReportSize        Size in bytes of the report received from the host
 202  */
 203 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 204                                           const void* ReportData, const uint16_t ReportSize)
 205 {
 206         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 207 }