pict14c2.c

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//<pre>
// pict14c.c
//
// Implementation of the PICT14.ASM program in Easy Pic 'N
// lookup demo using a 7 segment display. 
// It adds monitoring of the PortA switches to change the
// 7 segment display.
// There are probably a billion ways to do this one, but storing the
// table in ROM by using a constant is very efficient in .asm code.
// You might want to try doing this with a case statement and then
// with the lookup table (below). Big difference in amount of hex
// code that is generated!
//
// Using '84 on a board (simple solderless breadboard with
// 16F84 on it) and Peter Anderson's include file with 
// port/bit definitions (defs_f84.h available at www.phanderson.com)
// Settings:
// 	4Mhz resonator (not important)
//	All Port A inputs use external pullups (resistor SIP used)
//	Port B outputs tied to a 7 segment display (Radio Shack has 'em)
//	Port A inputs tied to ground through four switches
//	(pullups still are on them - makes it all work!)
//	Flip switch and the correct number should appear on the 7 segment
//	Note that you can only flip switches up to binary 1010 (10 decimal)
#case
#include <16f84.h>
#include <defs_f84.h>  // defines registers and bits
#fuses xt,nowdt,put,noprotect

int const table[10]= {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};

void main(void)
{
   TRISA=0x1f;   // make porta all inputs     
   TRISB=0x00;   // make portb all outputs
   PORTB=0;	 // clear portB
   while(1)
   {
     PORTB=table[PORTA]; // set PORTB with a table value based on 
			 // switch value in PORTA
			  
   }
}