ex2.h

#include <stdint.h>

/* objcopy creates _binary_x_raw_start and _binary_x_raw_end symbols for the
 * start and end of the embedded binary data.
 * SOUND_DECLARE and SOUND use preprocessor concatenation to import these
 * symbols and create abstract Sound structs from them.
 * the volatile keyword is used according to how the struct is used in interrupt
 * handlers.
 */
#define SOUND_DECLARE(name) \
extern int8_t _binary_##name##_raw_start[]; \
extern int8_t _binary_##name##_raw_end[];
#define SOUND(name) {_binary_##name##_raw_start, _binary_##name##_raw_end}
typedef struct {
	const int8_t *const start;
	const int8_t *const end;
	const volatile int8_t *pos; /* current position, or NULL if stopped */
} Sound;
extern volatile Sound sounds[8];

/* Declaration of peripheral setup functions */
void setup_timer(uint16_t period);
void setup_dac(void);
void setup_gpio(void);
void setup_nvic(void);
uint8_t read_buttons(void);
void write_dac(uint32_t data);