Contiki-NG
button.c
1 /*
2  * Copyright (c) 2006, Swedish Institute of Computer Science
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the Institute nor the names of its contributors
14  * may be used to endorse or promote products derived from this software
15  * without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 #include "contiki.h"
32 #include "dev/button.h"
33 #include "isr_compat.h"
34 
35 #define BUTTON_PORT 2
36 #define BUTTON_PIN 7
37 
38 static struct button_msg button_msg;
39 
40 static struct process *selecting_proc;
41 
42 void
43 button_init(struct process *proc)
44 {
45  button_msg.type = BUTTON_MSG_TYPE;
46 
47  P2DIR &= ~BV(BUTTON_PIN);
48  P2SEL &= ~BV(BUTTON_PIN);
49 
50  P2IES |= BV(BUTTON_PIN);
51  P2IFG &= ~BV(BUTTON_PIN);
52 
53  selecting_proc = proc;
54  if(proc != NULL)
55  P2IE |= BV(BUTTON_PIN);
56  else
57  P2IE &= ~BV(BUTTON_PIN);
58 }
59 
60 ISR(PORT2, __button_interrupt)
61 {
62  static struct timer debouncetimer;
63 
64  P2IFG &= ~BV(BUTTON_PIN);
65  if(timer_expired(&debouncetimer)) {
66  button_msg.value = P2IN & BV(BUTTON_PIN);
67  timer_set(&debouncetimer, CLOCK_SECOND/4);
68  if(selecting_proc != NULL) {
69  process_post(selecting_proc, PROCESS_EVENT_MSG, &button_msg);
70  }
71  LPM4_EXIT;
72  }
73 }
void timer_set(struct timer *t, clock_time_t interval)
Set a timer.
Definition: timer.c:64
A timer.
Definition: timer.h:82
#define CLOCK_SECOND
A second, measured in system clock time.
Definition: clock.h:82
int timer_expired(struct timer *t)
Check if a timer has expired.
Definition: timer.c:123
int process_post(struct process *p, process_event_t ev, process_data_t data)
Post an asynchronous event.
Definition: process.c:322