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 #include "Magstripe.h"
  33
  34 BitBuffer_t TrackDataBuffers[3];
  35
  36 USB_ClassInfo_HID_t Keyboard_HID_Interface =
  37         {
  38                 .InterfaceNumber         = 0,
  39
  40                 .ReportINEndpointNumber  = KEYBOARD_EPNUM,
  41                 .ReportINEndpointSize    = KEYBOARD_EPSIZE,
  42
  43                 .ReportINBufferSize      = sizeof(USB_KeyboardReport_Data_t),
  44         };
  45
  46 int main(void)
  47 {
  48         SetupHardware();
  49
  50         for (uint8_t Buffer = 0; Buffer < 3; Buffer++)
  51           BitBuffer_Init(&TrackDataBuffers[Buffer]);
  52
  53         for (;;)
  54         {
  55                 if (Magstripe_GetStatus() & MAG_CARDPRESENT)
  56                   ReadMagstripeData();
  57
  58                 USB_HID_USBTask(&Keyboard_HID_Interface);
  59                 USB_USBTask();
  60         }
  61 }
  62
  63 void SetupHardware(void)
  64 {
  65         /* Disable watchdog if enabled by bootloader/fuses */
  66         MCUSR &= ~(1 << WDRF);
  67         wdt_disable();
  68
  69         /* Disable clock division */
  70         clock_prescale_set(clock_div_1);
  71
  72         /* Hardware Initialization */
  73         Magstripe_Init();
  74         USB_Init();
  75
  76         /* Millisecond timer initialization, with output compare interrupt enabled for the idle timing */
  77         OCR0A  = ((F_CPU / 64) / 1000);
  78         TCCR0A = (1 << WGM01);
  79         TCCR0B = ((1 << CS01) | (1 << CS00));
  80         TIMSK0 = (1 << OCIE0A);
  81 }
  82
  83 void ReadMagstripeData(void)
  84 {
  85         /* Arrays to hold the buffer pointers, clock and data bit masks for the separate card tracks */
  86         const struct
  87         {
  88                 uint8_t ClockMask;
  89                 uint8_t DataMask;
  90         } TrackInfo[] = {{MAG_T1_CLOCK, MAG_T1_DATA},
  91                          {MAG_T2_CLOCK, MAG_T2_DATA},
  92                          {MAG_T3_CLOCK, MAG_T3_DATA}};
  93
  94         uint8_t Magstripe_Prev = 0;
  95         uint8_t Magstripe_LCL  = Magstripe_GetStatus();
  96
  97         while (Magstripe_LCL & MAG_CARDPRESENT)
  98         {
  99                 for (uint8_t Track = 0; Track < 3; Track++)
 100                 {
 101                         bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);
 102                         bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);
 103                         bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);
 104
 105                         if (ClockPinLevel && ClockLevelChanged)
 106                           BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);
 107                 }
 108
 109                 Magstripe_Prev = Magstripe_LCL;
 110                 Magstripe_LCL  = Magstripe_GetStatus();
 111         }
 112 }
 113
 114 void EVENT_USB_ConfigurationChanged(void)
 115 {
 116         USB_HID_ConfigureEndpoints(&Keyboard_HID_Interface);
 117 }
 118
 119 void EVENT_USB_UnhandledControlPacket(void)
 120 {
 121         USB_HID_ProcessControlPacket(&Keyboard_HID_Interface);
 122 }
 123
 124 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 125 {
 126         if (Keyboard_HID_Interface.IdleMSRemaining)
 127           Keyboard_HID_Interface.IdleMSRemaining--;
 128 }
 129
 130 uint16_t CALLBACK_USB_HID_CreateNextHIDReport(USB_ClassInfo_HID_t* HIDInterfaceInfo, void* ReportData)
 131 {
 132         static bool IsKeyReleaseReport;
 133         static bool IsNewlineReport;
 134
 135         BitBuffer_t*               Buffer         = NULL;
 136         USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;
 137
 138         /* Key reports must be interleaved with 0 Key Code reports to release the keys, or repeated keys will be ignored */
 139         IsKeyReleaseReport = !IsKeyReleaseReport;
 140
 141         if (IsKeyReleaseReport)
 142         {
 143                 KeyboardReport->KeyCode = 0;
 144         }
 145         else if (IsNewlineReport)
 146         {
 147                 IsNewlineReport = false;
 148                 KeyboardReport->KeyCode = KEY_ENTER;
 149         }
 150         else
 151         {
 152                 if (TrackDataBuffers[0].Elements)
 153                   Buffer = &TrackDataBuffers[0];
 154                 else if (TrackDataBuffers[1].Elements)
 155                   Buffer = &TrackDataBuffers[1];
 156                 else if (TrackDataBuffers[2].Elements)
 157                   Buffer = &TrackDataBuffers[2];
 158                 else
 159                   return 0;
 160
 161                 KeyboardReport->KeyCode = BitBuffer_GetNextBit(Buffer) ? KEY_1 : KEY_0;
 162
 163                 /* If buffer now empty, next report must be a newline to seperate track data */
 164                 if (!(Buffer->Elements))
 165                   IsNewlineReport = true;
 166         }
 167
 168         return sizeof(USB_KeyboardReport_Data_t);
 169 }
 170
 171 void CALLBACK_USB_HID_ProcessReceivedHIDReport(USB_ClassInfo_HID_t* HIDInterfaceInfo, void* ReportData, uint16_t ReportSize)
 172 {
 173         // Unused (but mandatory for the HID class driver) in this demo, since there are no Host->Device reports
 174 }