#define AO_MS_TO_SPEED(ms) ((ao_v_t) ((ms) * 16))
#define AO_MSS_TO_ACCEL(mss) ((ao_v_t) ((mss) * 16))
-extern uint16_t ao_sample_tick; /* time of last data */
+extern AO_TICK_TYPE ao_sample_tick; /* time of last data */
extern uint8_t ao_sample_adc; /* Ring position of last processed sample */
extern uint8_t ao_sample_data; /* Ring position of last processed sample */