Projects/Magstripe/Magstripe.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Denver Gingerich (denver [at] ossguy [dot] com)
  11   Copyright 2010  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 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                                 .ReportINEndpointDoubleBank = KEYBOARD_EPSIZE,
  64
  65                                 .PrevReportINBuffer         = PrevKeyboardHIDReportBuffer,
  66                                 .PrevReportINBufferSize     = sizeof(PrevKeyboardHIDReportBuffer),
  67                         },
  68         };
  69
  70 /** Main program entry point. This routine contains the overall program flow, including initial
  71  *  setup of all components and the main program loop.
  72  */
  73 int main(void)
  74 {
  75         SetupHardware();
  76
  77         for (uint8_t Buffer = 0; Buffer < TOTAL_TRACKS; Buffer++)
  78           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  79
  80         sei();
  81
  82         for (;;)
  83         {
  84                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  85                   ReadMagstripeData();
  86
  87                 HID_Device_USBTask(&Keyboard_HID_Interface);
  88                 USB_USBTask();
  89         }
  90 }
  91
  92 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  93 void SetupHardware(void)
  94 {
  95         /* Disable watchdog if enabled by bootloader/fuses */
  96         MCUSR &= ~(1 << WDRF);
  97         wdt_disable();
  98
  99         /* Disable clock division */
 100         clock_prescale_set(clock_div_1);
 101
 102         /* Hardware Initialization */
 103         Magstripe_Init();
 104         USB_Init();
 105 }
 106
 107 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 108  *  until they are read out to the host as a series of keyboard presses.
 109  */
 110 void ReadMagstripeData(void)
 111 {
 112         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 113         const struct
 114         {
 115                 uint8_t ClockMask;
 116                 uint8_t DataMask;
 117         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 118                          {MAG_T2_CLOCK, MAG_T2_DATA},
 119                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 120
 121         uint8_t Magstripe_Prev = 0;
 122         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 123
 124         while (Magstripe_LCL & MAG_CARDPRESENT)
 125         {
 126                 for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)
 127                 {
 128                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 129                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 130                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 131
 132                         /* Sample data on rising clock edges from the card reader */
 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         CurrentTrackBuffer = &TrackDataBuffers[0];
 142 }
 143
 144 /** Event handler for the library USB Configuration Changed event. */
 145 void EVENT_USB_Device_ConfigurationChanged(void)
 146 {
 147         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 148
 149         USB_Device_EnableSOFEvents();
 150 }
 151
 152 /** Event handler for the library USB Unhandled Control Packet event. */
 153 void EVENT_USB_Device_UnhandledControlRequest(void)
 154 {
 155         HID_Device_ProcessControlRequest(&Keyboard_HID_Interface);
 156 }
 157
 158 /** Event handler for the USB device Start Of Frame event. */
 159 void EVENT_USB_Device_StartOfFrame(void)
 160 {
 161         HID_Device_MillisecondElapsed(&Keyboard_HID_Interface);
 162 }
 163
 164 /** HID class driver callback function for the creation of HID reports to the host.
 165  *
 166  *  \param[in] HIDInterfaceInfo  Pointer to the HID class interface configuration structure being referenced
 167  *  \param[in,out] ReportID  Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 168  *  \param[in] ReportType  Type of the report to create, either REPORT_ITEM_TYPE_In or REPORT_ITEM_TYPE_Feature
 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                                          const uint8_t ReportType, 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[0] = 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[0] = 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[0] = 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] ReportType        The type of report that the host has sent, either REPORT_ITEM_TYPE_Out or REPORT_ITEM_TYPE_Feature
 210  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 211  *  \param[in] ReportSize        Size in bytes of the report received from the host
 212  */
 213 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 214                                           const uint8_t ReportType, const void* ReportData, const uint16_t ReportSize)
 215 {
 216         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 217 }