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[3];
  44
  45 /** LUFA HID Class driver interface configuration and state information. This structure is
  46  *  passed to all HID Class driver functions, so that multiple instances of the same class
  47  *  within a device can be differentiated from one another.
  48  */
  49 USB_ClassInfo_HID_Device_t Keyboard_HID_Interface =
  50         {
  51                 .InterfaceNumber         = 0,
  52
  53                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  54                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  55
  56                 .ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
  57         };
  58
  59 /** Main program entry point. This routine contains the overall program flow, including initial
  60  *  setup of all components and the main program loop.
  61  */
  62 int main(void)
  63 {
  64         SetupHardware();
  65
  66         for (uint8_t Buffer = 0; Buffer < 3; Buffer++)
  67           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  68
  69         for (;;)
  70         {
  71                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  72                   ReadMagstripeData();
  73
  74                 USB_HID_USBTask(&Keyboard_HID_Interface);
  75                 USB_USBTask();
  76         }
  77 }
  78
  79 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  80 void SetupHardware(void)
  81 {
  82         /* Disable watchdog if enabled by bootloader/fuses */
  83         MCUSR &= ~(1 << WDRF);
  84         wdt_disable();
  85
  86         /* Disable clock division */
  87         clock_prescale_set(clock_div_1);
  88
  89         /* Hardware Initialization */
  90         Magstripe_Init();
  91         USB_Init();
  92
  93         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
  94         OCR0A  = ((F_CPU / 64) / 1000);
  95         TCCR0A = (1 << WGM01);
  96         TCCR0B = ((1 << CS01) | (1 << CS00));
  97         TIMSK0 = (1 << OCIE0A);
  98 }
  99
 100 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 101  *  until they are read out to the host as a series of keyboard presses.
 102  */
 103 void ReadMagstripeData(void)
 104 {
 105         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 106         const struct
 107         {
 108                 uint8_t ClockMask;
 109                 uint8_t DataMask;
 110         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 111                          {MAG_T2_CLOCK, MAG_T2_DATA},
 112                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 113
 114         uint8_t Magstripe_Prev = 0;
 115         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 116
 117         while (Magstripe_LCL & MAG_CARDPRESENT)
 118         {
 119                 for (uint8_t Track = 0; Track < 3; Track++)
 120                 {
 121                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 122                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 123                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 124
 125                         if (ClockPinLevel && ClockLevelChanged)
 126                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 127                 }
 128
 129                 Magstripe_Prev = Magstripe_LCL;
 130                 Magstripe_LCL  = Magstripe_GetStatus();
 131         }
 132 }
 133
 134 /** Event handler for the library USB Configuration Changed event. */
 135 void EVENT_USB_ConfigurationChanged(void)
 136 {
 137         USB_HID_ConfigureEndpoints(&Keyboard_HID_Interface);
 138 }
 139
 140 /** Event handler for the library USB Unhandled Control Packet event. */
 141 void EVENT_USB_UnhandledControlPacket(void)
 142 {
 143         USB_HID_ProcessControlPacket(&Keyboard_HID_Interface);
 144 }
 145
 146 /** Timer 0 CTC ISR, firing once each millisecond to keep track of elapsed idle time in the HID interface. */
 147 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 148 {
 149         if (Keyboard_HID_Interface.IdleMSRemaining)
 150           Keyboard_HID_Interface.IdleMSRemaining--;
 151 }
 152
 153 /** HID Class driver callback function for the creation of a HID report for the host.
 154  *
 155  *  \param HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 156  *  \param ReportData  Pointer to the preallocated report buffer where the created report should be stored
 157  *
 158  *  \return Number of bytes in the created report
 159  */
 160 uint16_t CALLBACK_USB_HID_CreateNextHIDReport(USB_ClassInfo_HID_Device_t* HIDInterfaceInfo, uint8_t* ReportID, void* ReportData)
 161 {
 162         static bool IsKeyReleaseReport;
 163         static bool IsNewlineReport;
 164
 165         BitBuffer_t*               Buffer         = NULL;
 166         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 167
 168         /* Key reports must be interleaved with 0 Key Code reports to release the keys, or repeated keys will be ignored */
 169         IsKeyReleaseReport = !IsKeyReleaseReport;
 170
 171         if (IsKeyReleaseReport)
 172         {
 173                 KeyboardReport->KeyCode = 0;
 174         }
 175         else if (IsNewlineReport)
 176         {
 177                 IsNewlineReport = false;
 178                 KeyboardReport->KeyCode = KEY_ENTER;
 179         }
 180         else
 181         {
 182                 if (TrackDataBuffers[0].Elements)
 183                   Buffer = &TrackDataBuffers[0];
 184                 else if (TrackDataBuffers[1].Elements)
 185                   Buffer = &TrackDataBuffers[1];
 186                 else if (TrackDataBuffers[2].Elements)
 187                   Buffer = &TrackDataBuffers[2];
 188                 else
 189                   return 0;
 190
 191                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(Buffer) ? KEY_1 : KEY_0;
 192
 193                 /* If buffer now empty, next report must be a newline to seperate track data */
 194                 if (!(Buffer->Elements))
 195                   IsNewlineReport = true;
 196         }
 197
 198         return sizeof(USB_KeyboardReport_Data_t);
 199 }
 200
 201 /** HID Class driver callback function for the processing of a received HID report from the host.
 202  *
 203  *  \param HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 204  *  \param ReportData  Pointer to the report buffer where the received report is stored
 205  *  \param ReportSize  Size in bytes of the report received from the host
 206  */
 207 void CALLBACK_USB_HID_ProcessReceivedHIDReport(USB_ClassInfo_HID_Device_t* HIDInterfaceInfo, uint8_t ReportID,
 208                                                void* ReportData, uint16_t ReportSize)
 209 {
 210         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 211 }