1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
#include "common.h"
#include <stdio.h>
#include <string.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include "i2c.h"
#include "accel.h"
/* device address */
#define LIS302DL 0b00111000
/* registers */
#define LIS302DL_WHOAMI 0xf
#define LIS302DL_CTRLREG1 0x20
#define LIS302DL_UNUSED1 0x28
/* the first interrupt is lost */
static volatile bool drdy = true;
/* 0, 2 and 4 are zero, as they contain the dummy register’s content */
static volatile int8_t val[6] = {0, 0, 0, 0, 0, 0};
/* currently reading from i2c */
static bool reading = false;
#warning "wrong interrupt"
/* data ready interrupt
*/
ISR(PCINT1_vect) {
drdy = true;
}
void accelInit () {
/* set PB1 to input, with pull-up */
//DDRB = (DDRB & ~((1 << PB1)));
//PORTB = (PORTB | (1 << PB1));
/* enable interrupt PCI0 */
//PCICR = (1 << PCIE0);
/* enable interrupts on PB1/PCINT1 */
//PCMSK0 = (1 << 1);
}
/* XXX: make nonblocking */
void accelStart () {
/* configuration:
* disable power-down-mode
* defaults
* data ready interrupt on int2
*/
uint8_t data[] = {0b01000111, 0b0, 0b00100000};
if (!twRequest (TWM_WRITE, LIS302DL, LIS302DL_CTRLREG1, data,
sizeof (data)/sizeof (*data))) {
printf ("cannot start write\n");
}
sleepwhile (twr.status == TWST_WAIT);
printf ("final twi status was %i\n", twr.status);
}
bool accelProcess () {
if (reading) {
if (twr.status == TWST_OK) {
/* new data transfered */
reading = false;
return true;
} else if (twr.status == TWST_ERR) {
printf ("accel i2c error\n");
reading = false;
}
} else {
if (drdy && twr.status != TWST_WAIT) {
/* new data available in device buffer and bus is free, we are
* reading the registers inbetween out_x/y/z and ignore them */
if (!twRequest (TWM_READ, LIS302DL, LIS302DL_UNUSED1, (uint8_t *) val, 6)) {
printf ("cannot start read\n");
} else {
drdy = false;
reading = true;
}
}
}
return false;
}
|