Magstripe Project: Ensure that empty tracks still print out a newline seperator so...

[pub/USBasp.git] / Projects / Magstripe / Magstripe.c

diff --git a/Projects/Magstripe/Magstripe.c b/Projects/Magstripe/Magstripe.c
index 1151735..087e510 100644 (file)
--- a/Projects/Magstripe/Magstripe.c
+++ b/Projects/Magstripe/Magstripe.c
@@ -40,7 +40,10 @@
 /** Bit buffers to hold the read bits for each of the three magnetic card tracks before they are transmitted\r
  *  to the host as keyboard presses.\r
  */\r
-BitBuffer_t TrackDataBuffers[3];\r
+BitBuffer_t TrackDataBuffers[TOTAL_TRACKS];\r
+\r
+/** Pointer to the current track buffer being sent to the host. */\r
+BitBuffer_t* CurrentTrackBuffer = &TrackDataBuffers[TOTAL_TRACKS];\r
 \r
 /** LUFA HID Class driver interface configuration and state information. This structure is\r
  *  passed to all HID Class driver functions, so that multiple instances of the same class\r
@@ -71,7 +74,7 @@ int main(void)
 {\r
        SetupHardware();\r
        \r
-       for (uint8_t Buffer = 0; Buffer < 3; Buffer++)\r
+       for (uint8_t Buffer = 0; Buffer < TOTAL_TRACKS; Buffer++)\r
          BitBuffer_Init(&TrackDataBuffers[Buffer]);\r
 \r
        for (;;)\r
@@ -124,13 +127,13 @@ void ReadMagstripeData(void)
 \r
        while (Magstripe_LCL & MAG_CARDPRESENT)\r
        {\r
-               for (uint8_t Track = 0; Track < 3; Track++)\r
+               for (uint8_t Track = 0; Track < TOTAL_TRACKS; Track++)\r
                {\r
                        bool DataPinLevel      = ((Magstripe_LCL & TrackInfo[Track].DataMask) != 0);\r
                        bool ClockPinLevel     = ((Magstripe_LCL & TrackInfo[Track].ClockMask) != 0);\r
                        bool ClockLevelChanged = (((Magstripe_LCL ^ Magstripe_Prev) & TrackInfo[Track].ClockMask) != 0);\r
                \r
-                       /* Sample on rising clock edges */\r
+                       /* Sample data on rising clock edges from the card reader */\r
                        if (ClockPinLevel && ClockLevelChanged)\r
                          BitBuffer_StoreNextBit(&TrackDataBuffers[Track], DataPinLevel);\r
                }\r
@@ -138,6 +141,8 @@ void ReadMagstripeData(void)
                Magstripe_Prev = Magstripe_LCL;\r
                Magstripe_LCL  = Magstripe_GetStatus();\r
        }\r
+       \r
+       CurrentTrackBuffer = &TrackDataBuffers[0];\r
 }\r
 \r
 /** Event handler for the library USB Configuration Changed event. */\r
@@ -169,41 +174,28 @@ ISR(TIMER0_COMPA_vect, ISR_BLOCK)
  */\r
 uint16_t CALLBACK_HID_Device_CreateHIDReport(USB_ClassInfo_HID_Device_t* const HIDInterfaceInfo, uint8_t* const ReportID, void* ReportData)\r
 {\r
+       USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;\r
+\r
        static bool IsKeyReleaseReport;\r
-       static bool IsNewlineReport;\r
 \r
-       USB_KeyboardReport_Data_t* KeyboardReport = (USB_KeyboardReport_Data_t*)ReportData;\r
-       BitBuffer_t*               Buffer         = NULL;\r
-       \r
        /* Key reports must be interleaved with key release reports, or repeated keys will be ignored */\r
-       IsKeyReleaseReport = !IsKeyReleaseReport;       \r
+       IsKeyReleaseReport = !IsKeyReleaseReport;\r
 \r
-       if (IsKeyReleaseReport)\r
+       if ((IsKeyReleaseReport) || (CurrentTrackBuffer == &TrackDataBuffers[TOTAL_TRACKS]))\r
        {\r
+               /* No more data to send, or key release report between key presses */\r
                KeyboardReport->KeyCode = KEY_NONE;\r
        }\r
-       else if (IsNewlineReport)\r
+       else if (!(CurrentTrackBuffer->Elements))\r
        {\r
-               IsNewlineReport = false;\r
+               /* End of current track, send an enter press and change to the next track's buffer */\r
                KeyboardReport->KeyCode = KEY_ENTER;\r
+               CurrentTrackBuffer++;\r
        }\r
        else\r
        {\r
-               /* Read out tracks in ascending order - when each track buffer is empty, progress to next buffer */\r
-               if (TrackDataBuffers[0].Elements)\r
-                 Buffer = &TrackDataBuffers[0];\r
-               else if (TrackDataBuffers[1].Elements)\r
-                 Buffer = &TrackDataBuffers[1];                        \r
-               else if (TrackDataBuffers[2].Elements)\r
-                 Buffer = &TrackDataBuffers[2];\r
-               else\r
-                 return 0;\r
-\r
-               KeyboardReport->KeyCode = BitBuffer_GetNextBit(Buffer) ? KEY_1 : KEY_0;\r
-               \r
-               /* If current track buffer now empty, next report must be a newline to seperate track data */\r
-               if (!(Buffer->Elements))\r
-                 IsNewlineReport = true;\r
+               /* Still data in the current track; convert next bit to a 1 or 0 keypress */\r
+               KeyboardReport->KeyCode = BitBuffer_GetNextBit(CurrentTrackBuffer) ? KEY_1 : KEY_0;\r
        }\r
        \r
        return sizeof(USB_KeyboardReport_Data_t);\r