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 /** Buffer to hold the previously generated Keyboard HID report, for comparison purposes inside the HID class driver. */
  49 uint8_t PrevKeyboardHIDReportBuffer[sizeof(USB_KeyboardReport_Data_t)];
  50
  51 /** LUFA HID Class driver interface configuration and state information. This structure is
  52  *  passed to all HID Class driver functions, so that multiple instances of the same class
  53  *  within a device can be differentiated from one another.
  54  */
  55 USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
  56         {
  57                 .Config =
  58                         {
  59                                 .InterfaceNumber         = 0,
  60
  61                                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  62                                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  63
  64                                 .PrevReportINBuffer      = PrevKeyboardHIDReportBuffer,
  65                                 .PrevReportINBufferSize  = sizeof(PrevKeyboardHIDReportBuffer),
  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         for (uint8_t Buffer = 0; Buffer < TOTAL_TRACKS; Buffer++)
  77           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  78
  79         for (;;)
  80         {
  81                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  82                   ReadMagstripeData();
  83
  84                 HID_Device_USBTask(&Keyboard_HID_Interface);
  85                 USB_USBTask();
  86         }
  87 }
  88
  89 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  90 void SetupHardware(void)
  91 {
  92         /* Disable watchdog if enabled by bootloader/fuses */
  93         MCUSR &= ~(1 << WDRF);
  94         wdt_disable();
  95
  96         /* Disable clock division */
  97         clock_prescale_set(clock_div_1);
  98
  99         /* Hardware Initialization */
 100         Magstripe_Init();
 101         USB_Init();
 102
 103         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
 104         OCR0A  = ((F_CPU / 64) / 1000);
 105         TCCR0A = (1 << WGM01);
 106         TCCR0B = ((1 << CS01) | (1 << CS00));
 107         TIMSK0 = (1 << OCIE0A);
 108 }
 109
 110 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 111  *  until they are read out to the host as a series of keyboard presses.
 112  */
 113 void ReadMagstripeData(void)
 114 {
 115         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 116         const struct
 117         {
 118                 uint8_t ClockMask;
 119                 uint8_t DataMask;
 120         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 121                          {MAG_T2_CLOCK, MAG_T2_DATA},
 122                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 123
 124         uint8_t Magstripe_Prev = 0;
 125         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 126
 127         while (Magstripe_LCL & MAG_CARDPRESENT)
 128         {
 129                 for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)
 130                 {
 131                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 132                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 133                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 134
 135                         /* Sample data on rising clock edges from the card reader */
 136                         if (ClockPinLevel && ClockLevelChanged)
 137                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 138                 }
 139
 140                 Magstripe_Prev = Magstripe_LCL;
 141                 Magstripe_LCL  = Magstripe_GetStatus();
 142         }
 143
 144         CurrentTrackBuffer = &TrackDataBuffers[0];
 145 }
 146
 147 /** Event handler for the library USB Configuration Changed event. */
 148 void EVENT_USB_Device_ConfigurationChanged(void)
 149 {
 150         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 151 }
 152
 153 /** Event handler for the library USB Unhandled Control Packet event. */
 154 void EVENT_USB_Device_UnhandledControlRequest(void)
 155 {
 156         HID_Device_ProcessControlRequest(&Keyboard_HID_Interface);
 157 }
 158
 159 /** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */
 160 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 161 {
 162         HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);
 163 }
 164
 165 /** HID class driver callback function for the creation of HID reports to the host.
 166  *
 167  *  \param[in] HIDInterfaceInfo  Pointer to the HID class interface configuration structure being referenced
 168  *  \param[in,out] ReportID  Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 169  *  \param[out] ReportData  Pointer to a buffer where the created report should be stored
 170  *  \param[out] ReportSize  Number of bytes written in the report (or zero if no report is to be sent
 171  *
 172  *  \return Boolean true to force the sending of the report, false to let the library determine if it needs to be sent
 173  */
 174 bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID,
 175                                          void* ReportData, uint16_t* ReportSize)
 176 {
 177         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 178
 179         static bool IsKeyReleaseReport;
 180
 181         /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */
 182         IsKeyReleaseReport = !IsKeyReleaseReport;
 183
 184         if ((IsKeyReleaseReport) || (CurrentTrackBuffer == &TrackDataBuffers[TOTAL_TRACKS]))
 185         {
 186                 /* No more data to send, or key release report between key presses */
 187                 KeyboardReport->KeyCode = KEY_NONE;
 188         }
 189         else if (!(CurrentTrackBuffer->Elements))
 190         {
 191                 /* End of current track, send an enter press and change to the next track's buffer */
 192                 KeyboardReport->KeyCode = KEY_ENTER;
 193                 CurrentTrackBuffer++;
 194         }
 195         else
 196         {
 197                 /* Still data in the current track; convert next bit to a 1 or 0 keypress */
 198                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(CurrentTrackBuffer) ? KEY_1 : KEY_0;
 199         }
 200
 201         *ReportSize = sizeof(USB_KeyboardReport_Data_t);
 202         return false;
 203 }
 204
 205 /** HID Class driver callback function for the processing of a received HID report from the host.
 206  *
 207  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 208  *  \param[in] ReportID          Report ID of the received report from the host
 209  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 210  *  \param[in] ReportSize        Size in bytes of the report received from the host
 211  */
 212 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 213                                           const void* ReportData, const uint16_t ReportSize)
 214 {
 215         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 216 }