keys.c

/*
 * Copyright 2010 Travis Goodspeed, Michael Ossmann
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include <cc1110.h>
#include "keys.h"
#include "types.h"
#include "bits.h"

static u8 active_key;

//8 rows, 10 columns
__code const u8 keychars[] = {
  //gnd 0_1   1_2   1_3   1_4   1_5   1_6   1_7   0_6   0_7

  //row 0, gnd
  0x00, 0x00, 'O',  'K',  'N',  'M',  KPWR, 'P',  0x00, 0x00,
  //row 1
  0x00, 0x00, 'Y',  'G',  'C',  ' ',  '<',  ',',  KMNU, '>',
  //row 2
  0x00, 0x00, 0x00, 'Q',  'W',  'E',  'R',  'T',  'U',  'I',
  //row 3
  0x00, 0x00, 0x00, 0x00, 'A',  'S',  'D',  'F',  'H',  'J',
  //row 4
  0x00, 0x00, 0x00, 0x00, 0x00, KCAP, 'Z',  'X',  'V', 'B',
  //row 5
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, KSPK, KALT, KONL, KBACK,
  //row 6
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, KBYE, KDWN, '^',
  //row 7
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, '\n', 'L'
};

#define KEY(row,col) keychars[row*10+col]

u8 realkeyscan(){
  u8 row, col;
  
  //All input
  P0DIR &= ~(BIT1+BIT6+BIT7);
  P1DIR &= ~(BIT2+BIT3+BIT4+BIT5+BIT6+BIT7);
  P0 |= BIT1+BIT6+BIT7;
  P1 |= BIT2+BIT3+BIT4+BIT5+BIT6+BIT7;
  
  for(row=0;row<8;row++){
    col=row;//nothing
    switch(row){
    case 0://ground
    default:
      break;
    case 1: //P0_1
      P0DIR|=BIT1;
      P0&=~BIT1;
      break;
    case 2: //P1_2
      P1DIR|=BIT2;
      P1&=~BIT2;
      break;
    case 3: //P1_3
      P1DIR|=BIT3;
      P1&=~BIT3;
      break;
    case 4: //p1_4
      P1DIR|=BIT4;
      P1&=~BIT4;
      break;
    case 5: //p1_5
      P1DIR|=BIT5;
      P1&=~BIT5;
      break;
    case 6: //P1_6
      P1DIR|=BIT6;
      P1&=~BIT6;
      break;
    case 7: //P1_7
      P1DIR|=BIT7;
      P1&=~BIT7;
      break;
    }
    
    if(~P0&BIT1) col=1;
    if(~P1&BIT2) col=2;
    if(~P1&BIT3) col=3;
    if(~P1&BIT4) col=4;
    if(~P1&BIT5) col=5;
    if(~P1&BIT6) col=6;
    if(~P1&BIT7) col=7;
    if(~P0&BIT6) col=8;
    if(~P0&BIT7) col=9;
    
    if(col!=row) return KEY(row,col);
  }
  
  return '\0';
}

//! Returns the debounced character press.
u8 keyscan(){
  u8 key=realkeyscan();
  //debounce
  while(key!=realkeyscan())
    key=realkeyscan();
  
  //All input
  P0DIR &= ~(BIT1+BIT6+BIT7);
  P1DIR &= ~(BIT2+BIT3+BIT4+BIT5+BIT6+BIT7);
  P0 |= BIT1+BIT6+BIT7;
  P1 |= BIT2+BIT3+BIT4+BIT5+BIT6+BIT7;
  
  return key;
}

/* non-blocking check for a keypress */
u8 getkey() {
	u8 key = keyscan();

	/* keep track of key currently pressed to avoid rapid repeating */
	if (key != active_key)
		active_key = key;
	else
		key = 0x00;

	return key;
}