1 | /*
|
2 | * TASTER_LED.c
|
3 | *
|
4 | *
|
5 | *
|
6 | */
|
7 | #ifndef F_CPU
|
8 | #define F_CPU 1000000 // processor clock frequency
|
9 | #warning kein F_CPU definiert
|
10 | #endif
|
11 | #define REPEAT_MASK (1<<PD0 ) // repeat: key1, key2
|
12 | #define REPEAT_START 50 // after 500ms
|
13 | #define REPEAT_NEXT 20 // every 200ms
|
14 | #include <avr/io.h>
|
15 | #include <avr/interrupt.h>
|
16 |
|
17 |
|
18 | volatile uint8_t key_state; // debounced and inverted key state:
|
19 | // bit = 1: key pressed
|
20 | volatile uint8_t key_press; // key press detect
|
21 |
|
22 | volatile uint8_t key_rpt; // key long press and repeat
|
23 |
|
24 |
|
25 | ISR( TIMER0_OVF_vect ) // every 10ms
|
26 | {
|
27 | static uint8_t ct0, ct1, rpt;
|
28 | uint8_t i;
|
29 |
|
30 | TCNT0 = (uint8_t)(int16_t)-(F_CPU / 1024 * 10e-3 + 0.5); // preload for 10ms
|
31 |
|
32 | i = key_state ^ ~PIND; // key changed ?
|
33 | ct0 = ~( ct0 & i ); // reset or count ct0
|
34 | ct1 = ct0 ^ (ct1 & i); // reset or count ct1
|
35 | i &= ct0 & ct1; // count until roll over ?
|
36 | key_state ^= i; // then toggle debounced state
|
37 | key_press |= key_state & i; // 0->1: key press detect
|
38 |
|
39 | if( (key_state & REPEAT_MASK) == 0 ) // check repeat function
|
40 | rpt = REPEAT_START; // start delay
|
41 | if( --rpt == 0 ){
|
42 | rpt = REPEAT_NEXT; // repeat delay
|
43 | key_rpt |= key_state & REPEAT_MASK;
|
44 | }
|
45 | }
|
46 |
|
47 | ///////////////////////////////////////////////////////////////////
|
48 | //
|
49 | // check if a key has been pressed. Each pressed key is reported
|
50 | // only once
|
51 | //
|
52 | uint8_t get_key_press( uint8_t key_mask )
|
53 | {
|
54 | cli(); // read and clear atomic !
|
55 | key_mask &= key_press; // read key(s)
|
56 | key_press ^= key_mask; // clear key(s)
|
57 | sei();
|
58 | return key_mask;
|
59 | }
|
60 |
|
61 | ///////////////////////////////////////////////////////////////////
|
62 | //
|
63 | // check if a key has been pressed long enough such that the
|
64 | // key repeat functionality kicks in. After a small setup delay
|
65 | // the key is reported being pressed in subsequent calls
|
66 | // to this function. This simulates the user repeatedly
|
67 | // pressing and releasing the key.
|
68 | //
|
69 | uint8_t get_key_rpt( uint8_t key_mask )
|
70 | {
|
71 | cli(); // read and clear atomic !
|
72 | key_mask &= key_rpt; // read key(s)
|
73 | key_rpt ^= key_mask; // clear key(s)
|
74 | sei();
|
75 | return key_mask;
|
76 | }
|
77 |
|
78 | ///////////////////////////////////////////////////////////////////
|
79 | //
|
80 | // check if a key is pressed right now
|
81 | //
|
82 | uint8_t get_key_state( uint8_t key_mask )
|
83 |
|
84 | {
|
85 | key_mask &= key_state;
|
86 | return key_mask;
|
87 | }
|
88 |
|
89 | ///////////////////////////////////////////////////////////////////
|
90 | //
|
91 | uint8_t get_key_short( uint8_t key_mask )
|
92 | {
|
93 | cli(); // read key state and key press atomic !
|
94 | return get_key_press( ~key_state & key_mask );
|
95 | }
|
96 |
|
97 | ///////////////////////////////////////////////////////////////////
|
98 | //
|
99 | uint8_t get_key_long( uint8_t key_mask )
|
100 | {
|
101 | return get_key_press( get_key_rpt( key_mask ));
|
102 | }
|
103 |
|
104 | int main( void )
|
105 | {
|
106 | PORTB = 0xFF;
|
107 | DDRB = 0xFF;
|
108 |
|
109 | DDRD =0x00; // configure key port for input
|
110 | PORTD =0x00; // and turn on pull up resistors
|
111 |
|
112 | TCCR0 = (1<<CS02)|(1<<CS00); // divide by 1024
|
113 | TCNT0 = (uint8_t)(int16_t)-(F_CPU / 1024 * 10e-3 + 0.5); // preload for 10ms
|
114 | TIMSK |= 1<<TOIE0; // enable timer interrupt
|
115 |
|
116 | sei();
|
117 |
|
118 | while(1){
|
119 | if( get_key_short( 1<<PD0 ))
|
120 | PORTB ^= 1<<PB0;
|
121 |
|
122 |
|
123 | // if( get_key_long( 1<<PD0 ))
|
124 | // PORTB ^= 1<<PB1;
|
125 |
|
126 |
|
127 |
|
128 |
|
129 |
|
130 |
|
131 | //if( get_key_press( 1<<KEY2 get_key_rpt( 1<<KEY2 )){
|
132 | //uint8_t i = LED_PORT;
|
133 |
|
134 | //i = (i & 0x07) | ((i << 1) & 0xF0);
|
135 | //if( i < 0xF0 )
|
136 | // i |= 0x08;
|
137 | //LED_PORT = i;
|
138 | //}
|
139 | }
|
140 | }
|