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                 .Config =
  52                         {
  53                                 .InterfaceNumber         = 0,
  54
  55                                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  56                                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  57
  58                                 .ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
  59                         },
  60
  61                 .State =
  62                         {
  63                                 // Leave all state values to their defaults
  64                         }
  65         };
  66
  67 /** Main program entry point. This routine contains the overall program flow, including initial
  68  *  setup of all components and the main program loop.
  69  */
  70 int main(void)
  71 {
  72         SetupHardware();
  73
  74         for (uint8_t Buffer = 0; Buffer < 3; Buffer++)
  75           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  76
  77         for (;;)
  78         {
  79                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  80                   ReadMagstripeData();
  81
  82                 HID_Device_USBTask(&Keyboard_HID_Interface);
  83                 USB_USBTask();
  84         }
  85 }
  86
  87 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  88 void SetupHardware(void)
  89 {
  90         /* Disable watchdog if enabled by bootloader/fuses */
  91         MCUSR &= ~(1 << WDRF);
  92         wdt_disable();
  93
  94         /* Disable clock division */
  95         clock_prescale_set(clock_div_1);
  96
  97         /* Hardware Initialization */
  98         Magstripe_Init();
  99         USB_Init();
 100
 101         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
 102         OCR0A  = ((F_CPU / 64) / 1000);
 103         TCCR0A = (1 << WGM01);
 104         TCCR0B = ((1 << CS01) | (1 << CS00));
 105         TIMSK0 = (1 << OCIE0A);
 106 }
 107
 108 /** Determines if a card has been inserted, and if so reads in each track's contents into the bit buffers
 109  *  until they are read out to the host as a series of keyboard presses.
 110  */
 111 void ReadMagstripeData(void)
 112 {
 113         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
 114         const struct
 115         {
 116                 uint8_t ClockMask;
 117                 uint8_t DataMask;
 118         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
 119                          {MAG_T2_CLOCK, MAG_T2_DATA},
 120                          {MAG_T3_CLOCK, MAG_T3_DATA}};
 121
 122         uint8_t Magstripe_Prev = 0;
 123         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
 124
 125         while (Magstripe_LCL & MAG_CARDPRESENT)
 126         {
 127                 for (uint8_t Track = 0; Track < 3; Track++)
 128                 {
 129                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 130                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 131                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 132
 133                         /* Sample on rising clock edges */
 134                         if (ClockPinLevel && ClockLevelChanged)
 135                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 136                 }
 137
 138                 Magstripe_Prev = Magstripe_LCL;
 139                 Magstripe_LCL  = Magstripe_GetStatus();
 140         }
 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         static bool IsKeyReleaseReport;
 173         static bool IsNewlineReport;
 174
 175         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 176         BitBuffer_t*               Buffer         = NULL;
 177
 178         /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */
 179         IsKeyReleaseReport = !IsKeyReleaseReport;
 180
 181         if (IsKeyReleaseReport)
 182         {
 183                 KeyboardReport->KeyCode = KEY_NONE;
 184         }
 185         else if (IsNewlineReport)
 186         {
 187                 IsNewlineReport = false;
 188                 KeyboardReport->KeyCode = KEY_ENTER;
 189         }
 190         else
 191         {
 192                 /* Read out tracks in ascending order - when each track buffer is empty, progress to next buffer */
 193                 if (TrackDataBuffers[0].Elements)
 194                   Buffer = &TrackDataBuffers[0];
 195                 else if (TrackDataBuffers[1].Elements)
 196                   Buffer = &TrackDataBuffers[1];
 197                 else if (TrackDataBuffers[2].Elements)
 198                   Buffer = &TrackDataBuffers[2];
 199                 else
 200                   return 0;
 201
 202                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(Buffer) ? KEY_1 : KEY_0;
 203
 204                 /* If current track buffer now empty, next report must be a newline to seperate track data */
 205                 if (!(Buffer->Elements))
 206                   IsNewlineReport = true;
 207         }
 208
 209         return sizeof(USB_KeyboardReport_Data_t);
 210 }
 211
 212 /** HID Class driver callback function for the processing of a received HID report from the host.
 213  *
 214  *  \param[in] HIDInterfaceInfo  Pointer to the HID interface structure for the HID interface being referenced
 215  *  \param[in] ReportID          Report ID of the received report from the host
 216  *  \param[in] ReportData        Pointer to the report buffer where the received report is stored
 217  *  \param[in] ReportSize        Size in bytes of the report received from the host
 218  */
 219 void CALLBACK_HID_Device_ProcessHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, const uint8_t ReportID,
 220                                           const void* ReportData, const uint16_t ReportSize)
 221 {
 222         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 223 }