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-rw-r--r--main.c34
1 files changed, 31 insertions, 3 deletions
diff --git a/main.c b/main.c
index 6c23e32..62e10d3 100644
--- a/main.c
+++ b/main.c
@@ -3,6 +3,7 @@
#include <avr/io.h>
#include <avr/interrupt.h>
+#include <avr/sleep.h>
#include <util/delay.h>
#include <util/twi.h>
#include <stdio.h>
@@ -342,11 +343,24 @@ ISR(TWI_vect) {
}
}
+volatile unsigned char count;
+
+ISR(TIMER0_OVF_vect) {
+ ++count;
+ //printf ("timer interrupt hit, count now %u\n", count);
+}
+
+#define sleepwhile(cond) \
+ sleep_enable (); \
+ while (cond) { sleep_cpu (); } \
+ sleep_disable ();
+
int main(void) {
cpuInit ();
ledInit ();
twInit ();
uartInit ();
+ set_sleep_mode (SLEEP_MODE_IDLE);
/* redirect stdout */
stdout = &mystdout;
@@ -359,7 +373,7 @@ int main(void) {
if (!twWrite (LIS302DL, LIS302DL_CTRLREG1, 0b01000111)) {
printf ("cannot start write\n");
}
- while (twr.status == TWST_WAIT);
+ sleepwhile (twr.status == TWST_WAIT);
printf ("final twi status was %i\n", twr.status);
while (1) {
@@ -367,10 +381,24 @@ int main(void) {
if (!twReadMulti (LIS302DL, 0x28, val, 6)) {
printf ("cannot start read\n");
}
- while (twr.status == TWST_WAIT);
+ sleepwhile (twr.status == TWST_WAIT);
printf ("%i/%i/%i\n", (int8_t) val[1], (int8_t) val[3], (int8_t) val[5]);
+
+ count = 0;
+ /* set normal mode timer0 */
+ TCCR0A = 0;
+ /* io clock with 1024 prescaler */
+ TCCR0B = (TCCR0B & ~((1 << CS01)) | (1 << CS02) | (1 << CS00));
+ /* enable overflow interrupt */
+ TIMSK0 = (1 << TOIE0);
+
+ sleepwhile (count < 3);
+
+ /* stop timer (zero clock source) */
+ TCCR0B = 0;
+
/* XXX: why do we need the delay here? */
- _delay_ms (250);
+ //_delay_ms (250);
}
/* global interrupt disable */
cli ();