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