/////////////////////////////////////////////////////////////////////////
//// EX_MCR.C ////
//// ////
//// This example program demonstrates the use of a magnetic card ////
//// reader and MCR.C. The program calls mcr_read() and passes in ////
//// pointers to two arrays. The mcr_read() will fill the arrays ////
//// data read by the card reader. The data is then displayed and ////
//// any errors are reported. ////
//// ////
/////////////////////////////////////////////////////////////////////////
//// (C) Copyright 1996,2003 Custom Computer Services ////
//// This source code may only be used by licensed users of the CCS ////
//// C compiler. This source code may only be distributed to other ////
//// licensed users of the CCS C compiler. No other use, ////
//// reproduction or distribution is permitted without written ////
//// permission. Derivative programs created using this software ////
//// in object code form are not restricted in any way. ////
/////////////////////////////////////////////////////////////////////////
#if defined(__PCM__)
#include <16F877.h>
#device *=16
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#elif defined(__PCH__)
#include <18F452.h>
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#endif
// Included for card read functionality
#include "mcr.c"
void main()
{
int index;
int error;
char Track1[79];
char Track2[40];
while(TRUE)
{
printf("\r\n\nWaiting to read magnetic card...\r\n");
// Read a card and get any errors
error = mcr_read(Track1, Track2);
// Display the data in track 1
index=0;
printf("Track1 Data:\r\n");
// Loop until the end sentinel (?) is displayed.
// This loop does not display the LRC character.
do
{
// Display the character and increment the index
putc(Track1[index++]);
}while(Track1[index-1] != '?' && index<79);
// Display the data in track 2
index=0;
printf("\r\nTrack2 Data:\r\n");
// Loop until the end sentinel (?) is displayed.
// This loop does not display the LRC character.
do
{
// Display the character and increment the index
putc(Track2[index++]);
}while(Track2[index-1] != '?' && index<40);
// Check for card reading errors
if(error & MCR_ERR_PARITY1)
{
printf("\r\nTrack 1 parity error");
}
if(error & MCR_ERR_PARITY2)
{
printf("\r\nTrack 2 parity error");
}
if(error & MCR_ERR_LRC1)
{
printf("\r\nTrack 1 LRC error");
}
if(error & MCR_ERR_LRC2)
{
printf("\r\nTrack 2 LRC error");
}
}#include <16F877A.h>
#device adc=8
#FUSES NOWDT //No Watch Dog Timer
#FUSES HS //High speed Osc (> 4mhz)
#FUSES PUT //Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOBROWNOUT //No brownout reset
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOCPD //No EE protection
#FUSES NOWRT //Program memory not write protected
#use delay(clock=20000000)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
#ifndef MCR_CARD_PRESENT
#[B]define MCR_CARD_PRESENT PIN_B0
#define MCR_DATA PIN_B4
#define MCR_STROBE PIN_B5[/B]
#endif
#define MCR_ERR_PARITY 2
#define MCR_ERR_LRC 8
int mcr_read(char* track2)
{
int error = 0;
int1 dataBit = 0;
int1 ST = 1;
int1 ST_old = 1;
int1 firstOne = 0;
int1 parity = 0;
int count = 0;
int index = 0;
int LRC = 0;
// Wait for card to be present
while(input(MCR_CARD_PRESENT));
// Loop until a card is not present
while(!input(MCR_CARD_PRESENT))
{
// Check for NULL pointer and an index less than 40
if(track2 != 0 && index < 40)
{
// Get strobe
ST = input(MCR_STROBE);
// If the strobe was high and is now low (falling edge),
//then data is present
if(ST == 0 && ST_old == 1)
{
ST_old = 0;
// Check if the first 1 was received
if(firstOne == 1)
{
// Check if 4 bits of data were received
if(count == 4)
{
// Reset the bit counter back to 0
count = 0;
// Shift the bits right by 4
*(track2+index) >>= 4;
// Verify the LRC
if(*(track2+index-1) == '?' && LRC != *(track2+index))
{
error |= MCR_ERR_LRC;
}
else
{
LRC ^= *(track2+index);
}
// Add 0x30 to convert to ASCII
*(track2+index) += 0x30;
// Check the parity bit. The parity on a 0 is not checked
// because of the trailing zeros after the LRC character
if(!input(MCR_DATA) != parity && *(track2+index) != '0')
{
error |= MCR_ERR_PARITY;
}
// Reset the parity check
parity = 1;
// Increment the index into the array
++index;
}
else
{
// Get a bit of data from the card
dataBit = !input(MCR_DATA);
// XOR the data with the parity bit
parity ^= dataBit;
// Store the new bit of data
shift_right(track2+index, 1, dataBit);
// Increment the bit counter
++count;
}
}
else
{
// Check if the first 1 has appeard on the data line
if(!input(MCR_DATA))
{
// Set the first 1 received flag
firstOne = 1;
// Store the first 1
shift_right(track2, 1, 1);
// Increment the bit counter
++count;
}
}
}
else if(ST == 1)
{
ST_old = 1;
}
}
}
// Return any errors
return error;
}
void main()
{
int index;
int error;
char Track2[40];
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
// TODO: USER CODE!!
while(TRUE)
{
printf("\r\n\nWaiting to read magnetic card...\r\n");
// Read a card and get any errors
error = mcr_read(Track2);
// Display the data in track 2
index=0;
printf("\r\nTrack2 Data:\r\n");
// Loop until the end sentinel (?) is displayed.
// This loop does not display the LRC character.
do
{
//Display the character and increment the index
putc(Track2[index++]);
}
while(Track2[index-1] != '?' && index<40);
// Check for card reading errors
if(error & MCR_ERR_PARITY)
{
printf("\r\nTrack 2 parity error");
}
if(error & MCR_ERR_LRC)
{
printf("\r\nTrack 2 LRC error");
}
}
}
