Projects/Magstripe/Magstripe.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2017.
   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 2017  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 disclaims 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            = INTERFACE_ID_Keyboard,
  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         GlobalInterruptEnable();
  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 #if (ARCH == ARCH_AVR8)
  98         /* Disable watchdog if enabled by bootloader/fuses */
  99         MCUSR &= ~(1 << WDRF);
 100         wdt_disable();
 101
 102         /* Disable clock division */
 103         clock_prescale_set(clock_div_1);
 104 #endif
 105
 106         /* Hardware Initialization */
 107         Magstripe_Init();
 108         USB_Init();
 109 }
 110
 111 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 112  *  until they are read out to the host as a series of keyboard presses.
 113  */
 114 void ReadMagstripeData(void)
 115 {
 116         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 117         const struct
 118         {
 119                 uint8_t ClockMask;
 120                 uint8_t DataMask;
 121         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 122                          {MAG_T2_CLOCK, MAG_T2_DATA},
 123                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 124
 125         uint8_t Magstripe_Prev = 0;
 126         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 127
 128         while (Magstripe_LCL & MAG_CARDPRESENT)
 129         {
 130                 for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)
 131                 {
 132                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 133                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 134                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 135
 136                         /* Sample data on rising clock edges from the card reader */
 137                         if (ClockPinLevel && ClockLevelChanged)
 138                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 139                 }
 140
 141                 Magstripe_Prev = Magstripe_LCL;
 142                 Magstripe_LCL  = Magstripe_GetStatus();
 143         }
 144
 145         CurrentTrackBuffer = &TrackDataBuffers[0];
 146 }
 147
 148 /** Event handler for the library USB Configuration Changed event. */
 149 void EVENT_USB_Device_ConfigurationChanged(void)
 150 {
 151         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 152
 153         USB_Device_EnableSOFEvents();
 154 }
 155
 156 /** Event handler for the library USB Control Request reception event. */
 157 void EVENT_USB_Device_ControlRequest(void)
 158 {
 159         HID_Device_ProcessControlRequest(&Keyboard_HID_Interface);
 160 }
 161
 162 /** Event handler for the USB device Start Of Frame event. */
 163 void EVENT_USB_Device_StartOfFrame(void)
 164 {
 165         HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);
 166 }
 167
 168 /** HID class driver callback function for the creation of HID reports to the host.
 169  *
 170  *  \param[in]     HIDInterfaceInfo  Pointer to the HID class interface configuration structure being referenced
 171  *  \param[in,out] ReportID    Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 172  *  \param[in]     ReportType  Type of the report to create, either HID_REPORT_ITEM_In or HID_REPORT_ITEM_Feature
 173  *  \param[out]    ReportData  Pointer to a buffer where the created report should be stored
 174  *  \param[out]    ReportSize  Number of bytes written in the report (or zero if no report is to be sent)
 175  *
 176  *  \return Boolean \c true to force the sending of the report, \c false to let the library determine if it needs to be sent
 177  */
 178 bool CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo,
 179                                          uint8_t* const ReportID,
 180                                          const uint8_t ReportType,
 181                                          void* ReportData,
 182                                          uint16_t* const ReportSize)
 183 {
 184         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 185
 186         static bool IsKeyReleaseReport;
 187
 188         /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */
 189         IsKeyReleaseReport = !IsKeyReleaseReport;
 190
 191         if ((IsKeyReleaseReport) || (CurrentTrackBuffer == &TrackDataBuffers[TOTAL_TRACKS]))
 192         {
 193                 /* No more data to send, or key release report between key presses */
 194                 KeyboardReport->KeyCode[0] = KEY_NONE;
 195         }
 196         else if (!(CurrentTrackBuffer->Elements))
 197         {
 198                 /* End of current track, send an enter press and change to the next track's buffer */
 199                 KeyboardReport->KeyCode[0] = KEY_ENTER;
 200                 CurrentTrackBuffer++;
 201         }
 202         else
 203         {
 204                 /* Still data in the current track; convert next bit to a 1 or 0 keypress */
 205                 KeyboardReport->KeyCode[0] = BitBuffer_GetNextBit(CurrentTrackBuffer) ? KEY_1 : KEY_0;
 206         }
 207
 208         *ReportSize = sizeof(USB_KeyboardReport_Data_t);
 209         return false;
 210 }
 211
 212 /** HID Class driver callback function for the processing of a received HID report from the host.
 213  *
 214  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 215  *  \param[in] ReportID          Report ID of the received report from the host
 216  *  \param[in] ReportType        The type of report that the host has sent, either HID_REPORT_ITEM_Out or HID_REPORT_ITEM_Feature
 217  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 218  *  \param[in] ReportSize        Size in bytes of the report received from the host
 219  */
 220 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo,
 221                                           const uint8_t ReportID,
 222                                           const uint8_t ReportType,
 223                                           const void* ReportData,
 224                                           const uint16_t ReportSize)
 225 {
 226         // Ignore keyboard LED reports from the host, but still need to declare the callback routine
 227 }
 228