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
  65 /** Main program entry point. This routine contains the overall program flow, including initial
  66  *  setup of all components and the main program loop.
  67  */
  68 int main(void)
  69 {
  70         SetupHardware();
  71
  72         for (uint8_t Buffer = 0; Buffer < TOTAL_TRACKS; Buffer++)
  73           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  74
  75         for (;;)
  76         {
  77                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  78                   ReadMagstripeData();
  79
  80                 HID_Device_USBTask(&Keyboard_HID_Interface);
  81                 USB_USBTask();
  82         }
  83 }
  84
  85 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  86 void SetupHardware(void)
  87 {
  88         /* Disable watchdog if enabled by bootloader/fuses */
  89         MCUSR &= ~(1 << WDRF);
  90         wdt_disable();
  91
  92         /* Disable clock division */
  93         clock_prescale_set(clock_div_1);
  94
  95         /* Hardware Initialization */
  96         Magstripe_Init();
  97         USB_Init();
  98
  99         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
 100         OCR0A  = ((F_CPU / 64) / 1000);
 101         TCCR0A = (1 << WGM01);
 102         TCCR0B = ((1 << CS01) | (1 << CS00));
 103         TIMSK0 = (1 << OCIE0A);
 104 }
 105
 106 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 107  *  until they are read out to the host as a series of keyboard presses.
 108  */
 109 void ReadMagstripeData(void)
 110 {
 111         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 112         const struct
 113         {
 114                 uint8_t ClockMask;
 115                 uint8_t DataMask;
 116         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 117                          {MAG_T2_CLOCK, MAG_T2_DATA},
 118                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 119
 120         uint8_t Magstripe_Prev = 0;
 121         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 122
 123         while (Magstripe_LCL & MAG_CARDPRESENT)
 124         {
 125                 for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)
 126                 {
 127                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 128                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 129                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 130
 131                         /* Sample data on rising clock edges from the card reader */
 132                         if (ClockPinLevel && ClockLevelChanged)
 133                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 134                 }
 135
 136                 Magstripe_Prev = Magstripe_LCL;
 137                 Magstripe_LCL  = Magstripe_GetStatus();
 138         }
 139
 140         CurrentTrackBuffer = &TrackDataBuffers[0];
 141 }
 142
 143 /** Event handler for the library USB Configuration Changed event. */
 144 void EVENT_USB_ConfigurationChanged(void)
 145 {
 146         HID_Device_ConfigureEndpoints(&Keyboard_HID_Interface);
 147 }
 148
 149 /** Event handler for the library USB Unhandled Control Packet event. */
 150 void EVENT_USB_UnhandledControlPacket(void)
 151 {
 152         HID_Device_ProcessControlPacket(&Keyboard_HID_Interface);
 153 }
 154
 155 /** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */
 156 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 157 {
 158         if (Keyboard_HID_Interface.State.IdleMSRemaining)
 159           Keyboard_HID_Interface.State.IdleMSRemaining--;
 160 }
 161
 162 /** HID Class driver callback function for the creation of a HID report for the host.
 163  *
 164  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface 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[out] ReportData       Pointer to the preallocated report buffer where the created report should be stored
 167  *
 168  *  \return Number of bytes in the created report
 169  */
 170 uint16_t CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID, void* ReportData)
 171 {
 172         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 173
 174         static bool IsKeyReleaseReport;
 175
 176         /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */
 177         IsKeyReleaseReport = !IsKeyReleaseReport;
 178
 179         if ((IsKeyReleaseReport) || (CurrentTrackBuffer == &TrackDataBuffers[TOTAL_TRACKS]))
 180         {
 181                 /* No more data to send, or key release report between key presses */
 182                 KeyboardReport->KeyCode = KEY_NONE;
 183         }
 184         else if (!(CurrentTrackBuffer->Elements))
 185         {
 186                 /* End of current track, send an enter press and change to the next track's buffer */
 187                 KeyboardReport->KeyCode = KEY_ENTER;
 188                 CurrentTrackBuffer++;
 189         }
 190         else
 191         {
 192                 /* Still data in the current track; convert next bit to a 1 or 0 keypress */
 193                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(CurrentTrackBuffer) ? KEY_1 : KEY_0;
 194         }
 195
 196         return sizeof(USB_KeyboardReport_Data_t);
 197 }
 198
 199 /** HID Class driver callback function for the processing of a received HID report from the host.
 200  *
 201  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 202  *  \param[in] ReportID          Report ID of the received report from the host
 203  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 204  *  \param[in] ReportSize        Size in bytes of the report received from the host
 205  */
 206 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 207                                           const void* ReportData, const uint16_t ReportSize)
 208 {
 209         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 210 }