pusb.c

/* Keypad (16 switches) scanner and 7-seg digit LED refresh tasks
 *   needs to be run at least every 20ms (50Hz minimum)
 *   Linux version, 28-2-04
 * Converted to use the BMCM USB-PIO interface  1-10-11
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <libad.h>
#include <sys/termios.h>
#include <ctype.h>      // gcc keypad.c -lad4

#define FALSE 0
#define TRUE 1

#define DIOA (AD_CHA_TYPE_DIGITAL_IO|1)
#define DIOB (AD_CHA_TYPE_DIGITAL_IO|2)
#define DIOC (AD_CHA_TYPE_DIGITAL_IO|3)

#define COLSX 4
#define ROWSX 4

typedef unsigned char BYTE;
typedef unsigned int DWORD;

BYTE digits[COLSX] ={0,4,2,0};
const BYTE segtab[] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,
		       0x07,0x7F,0x6F,0x77,0x7C,0x58,0x5E,0x79,0x71,0x40,0xD3};
const BYTE keytab[] = {1,4,7,10, 2,5,8,0, 3,6,9,11, 15,14,13,12};

BYTE portAstatus = 0;
BYTE portBstatus = 0;
BYTE portCstatus = 0;
int pio;

int inithw(void) {
  int c, res;
  struct termios oldtio,newtio;
  char buf[255];
  /*
  pio = open(MODEMDEVICE, O_RDWR | O_NOCTTY ); 
  if (pio <0) {perror(MODEMDEVICE); exit(-1); }
  */

  if((pio = ad_open("usb-pio"))==-1){

    printf("failed to open USB driver\n");
    exit(1); 
  };
  ad_set_line_direction(pio, 1, 0x00);  // A 4 col sel output
  ad_set_line_direction(pio, 2, 0xFF);  // B 4 row sense input
  ad_set_line_direction(pio, 3, 0x00);  // C 8 7-nseg output

  return 0;
  
}

void writeFAB (int np, BYTE wd) {
 
  ad_digital_out(pio, np, wd);
}

BYTE readFAB (int np) {
  int x;
  ad_digital_in(pio, np, &x);
  return (BYTE) x;
}

int main () {
  BYTE key;
  int i;
  BYTE know;
  DWORD keyflags;
  BYTE colsel=-1;
  BYTE kpd0[COLSX];
  BYTE kpd1[COLSX];
  BYTE kpd2[COLSX];
  BYTE ktrue[COLSX];      //current true keypad status
  BYTE kedge[COLSX];
  BYTE kchange[COLSX];    //1 - key status changed

  inithw();

  while(1) {
  //  for(i = 0; i < 1000; i++) {
    colsel = (++colsel) % COLSX;
    //writeFAB(DIOC, 0);              // LEDS off or display lags and mashes 
    portAstatus = (BYTE) (01 << colsel);
    writeFAB(DIOA, portAstatus);    // next col/digit sel
    portCstatus = segtab[digits[colsel]];
    writeFAB(DIOC, portCstatus);    // next LEDs pattern on
    portBstatus = 0x0F & ~readFAB(DIOB);

    
    kpd2[colsel] = kpd1[colsel];
    kpd1[colsel] = kpd0[colsel];
    kpd0[colsel] = (BYTE)portBstatus;

    kchange[colsel] = (kpd0[colsel]^kpd1[colsel]) | (kpd1[colsel]^kpd2[colsel]); 
    know = (kpd2[colsel] & ~kchange[colsel]) | (ktrue[colsel] & kchange[colsel]);
    ktrue[colsel] = know;
    //printf("colsel = %x - know =%x - ktrue = %x\n",colsel,know,ktrue);
    
    /*
    printf("portAstatus = %x\n",portAstatus);
    printf("portBstatus = %x\n",portBstatus);
    printf("portCstatus = %x\n",portCstatus);
    */
    if (colsel == 3)
      {
	keyflags = 0;
	keyflags |=  ktrue[0] & 0x0F;
	keyflags |= (ktrue[1] & 0x0F) << 4;
	keyflags |= (ktrue[2] & 0x0F) << 8;
	keyflags |= (ktrue[3] & 0x0F) << 12;
	keyflags &= 0x0000ffff;
	//printf("keyflags = %x\n",keyflags);
	for(key=0; keyflags&1; keyflags>>=1) key++;
	//printf("key = %d\n",key);

	if (key <16) {
	  digits[0]= keytab[key];
	  digits[1]= 16;
	  digits[2]= key / 10;
	  digits[3]= key % 10;
	} else {
	  digits[0]= 17;
	  digits[1]= 16;
	  digits[2]= 0;
	  digits[3]= 0;
	}
      }
  }
  ad_close(pio);
  return 0;
}