git.rot13.org Git - digitaldcpower/blob - kbd.c

   1 /* vim: set sw=8 ts=8 si : */
   2 /*********************************************
   3 * Author: Guido Socher, Copyright: GPL
   4 *
   5 * read the keyboard
   6 **********************************************/
   7 #include <avr/io.h>
   8 #define F_CPU 8000000UL  // 4 MHz
   9 #include <util/delay.h>
  10
  11
  12 // it looks like output port settings need time to propagate. Maybe
  13 // caused by input capacitors on the lcd which connect to the same ports.
  14 static void kbd_wait(void){
  15         _delay_ms(7.5);
  16 }
  17
  18 // kbd connection:
  19 // U+=PC3, U-=PC4, I+,store=PB2, I-=PC5
  20 // common input wires: PB5, PB3 for store
  21 // PC3, PC4, PB2, PC5 are already initialized as output lines
  22 // by the LCD driver code
  23 void init_kbd(void)
  24 {
  25         // init lcd sets those already so we comment them out here:
  26         /*
  27         DDRC|=(1<<DDC3); // output line
  28         DDRC|=(1<<DDC4); // output line
  29         DDRB|=(1<<DDB2); // output line
  30         DDRC|=(1<<DDC5); // output line
  31         */
  32
  33         DDRB&= ~(1<<DDB5); // input line
  34         DDRB&= ~(1<<DDB3);
  35
  36         PORTB|= (1<<PINB5); // internal pullup resistor on
  37         PORTB|= (1<<PINB3); // internal pullup resistor on
  38 }
  39
  40 uint8_t check_u_button(int16_t *u)
  41 {
  42         // check U+ button:
  43         PORTC&=~(1<<PORTC3); // to gnd
  44         PORTC|=(1<<PORTC4); // to vcc
  45         PORTB|=(1<<PORTB2); // to vcc
  46         PORTC|=(1<<PORTC5); // to vcc
  47         kbd_wait();
  48         if (bit_is_clear(PINB,PINB5)){
  49                 (*u)++;
  50                 return(1);
  51         }
  52         // check U- button:
  53         PORTC|=(1<<PORTC3); // to vcc
  54         PORTC&=~(1<<PORTC4); // to gnd
  55         PORTB|=(1<<PORTB2); // to vcc
  56         PORTC|=(1<<PORTC5); // to vcc
  57         kbd_wait();
  58         if (bit_is_clear(PINB,PINB5) && (*u)>0){
  59                 (*u)--;
  60                 if((*u)<0){
  61                         (*u)=0;
  62                 }
  63                 return(1);
  64         }
  65         return(0);
  66 }
  67
  68 uint8_t check_i_button(int16_t *i)
  69 {
  70         // check I+ button:
  71         PORTC|=(1<<PORTC3); // to vcc
  72         PORTC|=(1<<PORTC4); // to vcc
  73         PORTB&=~(1<<PORTB2); // to gnd
  74         PORTC|=(1<<PORTC5); // to vcc
  75         kbd_wait();
  76         if (bit_is_clear(PINB,PINB5)){
  77                 (*i)++;
  78                 return(1);
  79         }
  80         // check I- button:
  81         PORTC|=(1<<PORTC3); // to vcc
  82         PORTC|=(1<<PORTC4); // to vcc
  83         PORTB|=(1<<PORTB2); // to vcc
  84         PORTC&=~(1<<PORTC5); // to gnd
  85         kbd_wait();
  86         if (bit_is_clear(PINB,PINB5) && (*i)>0){
  87                 (*i)--;
  88                 if((*i)<0){
  89                         (*i)=0;
  90                 }
  91                 return(1);
  92         }
  93         return(0);
  94 }
  95
  96 uint8_t check_store_button(void)
  97 {
  98         // check store button:
  99         PORTB&=~(1<<PORTB2); // to gnd
 100         kbd_wait();
 101         if (bit_is_clear(PINB,PINB3)){
 102                 return(1);
 103         }
 104         return(0);
 105 }