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RFID problem

 
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YarYesreh



Joined: 18 Mar 2009
Posts: 2

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RFID problem
PostPosted: Wed Apr 15, 2009 12:36 pm     Reply with quote
For a security system I'm working with, implemented with the 18F4520, there is an RFID reader http://www.parallax.com/dl/docs/prod/audiovis/RFID-Reader-v1.1.pdf. I have the RFID reader working but unfortunately I first figured this out in a continuous loop. I would like to just check if and only if the user has tried to scan an RFID card.

Here is what I have code wise so far
Code:
byte code[size];     //For read RFID code

void read_RFID()
{
   //printf(lcd_putc,"\fWaiting...\n");
   int x;
   output_low(PIN_B1);
   if(getc() == 0x00)
      return;
   //while (getc() == 0x00);

   for (x = 0; x < size; x++)
   {
       code[x] = getc();
   }
   output_high(PIN_B1);
   
   return;
}


The Commented while statement is what I was first using, and using the if doesn't seem to help any either. I know I probably missing something small but I can't see what.

Any help?
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

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PostPosted: Wed Apr 15, 2009 12:42 pm     Reply with quote
I'm not completely sure what you want, but I think the kbhit() function
may do it for you. If a character has been received by the UART, then
kbhit() will return 'True'.

The kbhit() function allows you to test and see if a character is available,
before you call getc(). If no character is ready, then don't call getc().
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