spi: mixture of old spi_update and new spi_readwrite interfaces, using spi mode3 for adxl345
#include "stdlib.h"
//#include "switch.h"
#include <avr/io.h>
#include <avr/interrupt.h>
byte switch_mask;
byte switch_status;
byte switch_state;
ISR(PCINT0_vect)
{
switch_status = 1;
switch_state = PINB;
}
ISR(PCINT1_vect)
{
switch_status = 1;
switch_state = PINC;
}
ISR(PCINT2_vect)
{
switch_status = 1;
switch_state = PIND;
}
byte switch_read (byte *sp)
{
if (!switch_status)
return 0;
switch_status = 0;
*sp = ~switch_state & switch_mask;
return 1;
}