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 /** LUFA HID Class driver interface configuration and state information. This structure is
  49  *  passed to all HID Class driver functions, so that multiple instances of the same class
  50  *  within a device can be differentiated from one another.
  51  */
  52 USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
  53         {
  54                 .Config =
  55                         {
  56                                 .InterfaceNumber         = 0,
  57
  58                                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  59                                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  60
  61                                 .ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
  62                         },
  63
  64                 .State =
  65                         {
  66                                 // Leave all state values to their defaults
  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         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
 105         OCR0A  = ((F_CPU / 64) / 1000);
 106         TCCR0A = (1 << WGM01);
 107         TCCR0B = ((1 << CS01) | (1 << CS00));
 108         TIMSK0 = (1 << OCIE0A);
 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_ConfigurationChanged(void)
 150 {
 151         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 152 }
 153
 154 /** Event handler for the library USB Unhandled Control Packet event. */
 155 void EVENT_USB_UnhandledControlPacket(void)
 156 {
 157         HID_Device_ProcessControlPacket(&Keyboard_HID_Interface);
 158 }
 159
 160 /** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */
 161 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 162 {
 163         if (Keyboard_HID_Interface.State.IdleMSRemaining)
 164           Keyboard_HID_Interface.State.IdleMSRemaining--;
 165 }
 166
 167 /** HID Class driver callback function for the creation of a HID report for the host.
 168  *
 169  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 170  *  \param[in,out] ReportID      Report ID requested by the host if non-zero, otherwise callback should set to the generated report ID
 171  *  \param[out] ReportData       Pointer to the preallocated report buffer where the created report should be stored
 172  *
 173  *  \return Number of bytes in the created report
 174  */
 175 uint16_t CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID, void* ReportData)
 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         return sizeof(USB_KeyboardReport_Data_t);
 202 }
 203
 204 /** HID Class driver callback function for the processing of a received HID report from the host.
 205  *
 206  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 207  *  \param[in] ReportID          Report ID of the received report from the host
 208  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 209  *  \param[in] ReportSize        Size in bytes of the report received from the host
 210  */
 211 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 212                                           const void* ReportData, const uint16_t ReportSize)
 213 {
 214         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 215 }