Projects/Magstripe/Magstripe.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 2010  Denver Gingerich (denver [at] ossguy [dot] com)
  11   Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [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 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 static BitBuffer_t TrackDataBuffers[TOTAL_TRACKS];
  44
  45 /** Pointer to the current track buffer being sent to the host. */
  46 static 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 static 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                                 .ReportINEndpoint           =
  61                                         {
  62                                                 .Address            = KEYBOARD_EPADDR,
  63                                                 .Size               = KEYBOARD_EPSIZE,
  64                                                 .Banks              = 1,
  65                                         },
  66                                 .PrevReportINBuffer         = PrevKeyboardHIDReportBuffer,
  67                                 .PrevReportINBufferSize     = sizeof(PrevKeyboardHIDReportBuffer),
  68                         },
  69         };
  70
  71
  72 /** Main program entry point. This routine contains the overall program flow, including initial
  73  *  setup of all components and the main program loop.
  74  */
  75 int main(void)
  76 {
  77         SetupHardware();
  78
  79         for (uint8_t Buffer = 0; Buffer < TOTAL_TRACKS; Buffer++)
  80           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  81
  82         sei();
  83
  84         for (;;)
  85         {
  86                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  87                   ReadMagstripeData();
  88
  89                 HID_Device_USBTask(&Keyboard_HID_Interface);
  90                 USB_USBTask();
  91         }
  92 }
  93
  94 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  95 void SetupHardware(void)
  96 {
  97         /* Disable watchdog if enabled by bootloader/fuses */
  98         MCUSR &= ~(1 << WDRF);
  99         wdt_disable();
 100
 101         /* Disable clock division */
 102         clock_prescale_set(clock_div_1);
 103
 104         /* Hardware Initialization */
 105         Magstripe_Init();
 106         USB_Init();
 107 }
 108
 109 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 110  *  until they are read out to the host as a series of keyboard presses.
 111  */
 112 void ReadMagstripeData(void)
 113 {
 114         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 115         const struct
 116         {
 117                 uint8_t ClockMask;
 118                 uint8_t DataMask;
 119         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 120                          {MAG_T2_CLOCK, MAG_T2_DATA},
 121                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 122
 123         uint8_t Magstripe_Prev = 0;
 124         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 125
 126         while (Magstripe_LCL & MAG_CARDPRESENT)
 127         {
 128                 for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)
 129                 {
 130                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 131                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 132                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 133
 134                         /* Sample data on rising clock edges from the card reader */
 135                         if (ClockPinLevel && ClockLevelChanged)
 136                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 137                 }
 138
 139                 Magstripe_Prev = Magstripe_LCL;
 140                 Magstripe_LCL  = Magstripe_GetStatus();
 141         }
 142
 143         CurrentTrackBuffer = &TrackDataBuffers[0];
 144 }
 145
 146 /** Event handler for the library USB Configuration Changed event. */
 147 void EVENT_USB_Device_ConfigurationChanged(void)
 148 {
 149         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 150
 151         USB_Device_EnableSOFEvents();
 152 }
 153
 154 /** Event handler for the library USB Control Request reception event. */
 155 void EVENT_USB_Device_ControlRequest(void)
 156 {
 157         HID_Device_ProcessControlRequest(&Keyboard_HID_Interface);
 158 }
 159
 160 /** Event handler for the USB device Start Of Frame event. */
 161 void EVENT_USB_Device_StartOfFrame(void)
 162 {
 163         HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);
 164 }
 165
 166 /** HID class driver callback function for the creation of HID reports to the host.
 167  *
 168  *  \param[in]     HIDInterfaceInfo  Pointer to the HID class interface configuration structure being referenced
 169  *  \param[in,out] ReportID    Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 170  *  \param[in]     ReportType  Type of the report to create, either HID_REPORT_ITEM_In or HID_REPORT_ITEM_Feature
 171  *  \param[out]    ReportData  Pointer to a buffer where the created report should be stored
 172  *  \param[out]    ReportSize  Number of bytes written in the report (or zero if no report is to be sent)
 173  *
 174  *  \return Boolean true to force the sending of the report, false to let the library determine if it needs to be sent
 175  */
 176 bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo,
 177                                          uint8_t* const ReportID,
 178                                          const uint8_t ReportType,
 179                                          void* ReportData,
 180                                          uint16_t* const ReportSize)
 181 {
 182         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 183
 184         static bool IsKeyReleaseReport;
 185
 186         /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */
 187         IsKeyReleaseReport = !IsKeyReleaseReport;
 188
 189         if ((IsKeyReleaseReport) || (CurrentTrackBuffer == &TrackDataBuffers[TOTAL_TRACKS]))
 190         {
 191                 /* No more data to send, or key release report between key presses */
 192                 KeyboardReport->KeyCode[0] = KEY_NONE;
 193         }
 194         else if (!(CurrentTrackBuffer->Elements))
 195         {
 196                 /* End of current track, send an enter press and change to the next track's buffer */
 197                 KeyboardReport->KeyCode[0] = KEY_ENTER;
 198                 CurrentTrackBuffer++;
 199         }
 200         else
 201         {
 202                 /* Still data in the current track; convert next bit to a 1 or 0 keypress */
 203                 KeyboardReport->KeyCode[0] = BitBuffer_GetNextBit(CurrentTrackBuffer) ? KEY_1 : KEY_0;
 204         }
 205
 206         *ReportSize = sizeof(USB_KeyboardReport_Data_t);
 207         return false;
 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] ReportType        The type of report that the host has sent, either HID_REPORT_ITEM_Out or HID_REPORT_ITEM_Feature
 215  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 216  *  \param[in] ReportSize        Size in bytes of the report received from the host
 217  */
 218 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo,
 219                                           const uint8_t ReportID,
 220                                           const uint8_t ReportType,
 221                                           const void* ReportData,
 222                                           const uint16_t ReportSize)
 223 {
 224         // Ignore keyboard LED reports from the host, but still need to declare the callback routine
 225 }
 226