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#include <stdio.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include "i2c.h"
#include "gyro.h"
/* device address */
#define L3GD20 0b11010100
/* registers */
#define L3GD20_WHOAMI 0xf
#define L3GD20_CTRLREG1 0x20
#define L3GD20_CTRLREG3 0x22
#define L3GD20_CTRLREG4 0x23
#define sleepwhile(cond) \
sleep_enable (); \
while (cond) { sleep_cpu (); } \
sleep_disable ();
/* the first interrupt is lost */
volatile bool drdy = true;
volatile int16_t val[3] = {0, 0, 0};
/* data ready interrupt
*/
ISR(PCINT0_vect) {
drdy = true;
}
void gyroInit () {
/* 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 gyroStart () {
/* configuration:
* disable power-down-mode
* defaults
* enable drdy interrupt
* select 500dps
*/
uint8_t data[] = {0b00001111, 0b0, 0b00001000, 0b00010000};
if (!twRequest (TWM_WRITE, L3GD20, L3GD20_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 gyroRead () {
if (drdy) {
drdy = false;
if (!twRequest (TWM_READ, L3GD20, 0x28, (uint8_t *) val, 6)) {
printf ("cannot start read\n");
}
return true;
} else {
return false;
}
}
volatile const int16_t *gyroGet () {
return val;
}
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