/** library to determine range using HC-SR04 ultrasonic range sensor
 *  @file
 *  @author King Kévin <kingkevin@cuvoodoo.info>
 *  @copyright SPDX-License-Identifier: GPL-3.0-or-later
 *  @date 2020
 *  @note peripherals used: timer @ref sensor_sr04_timer, GPIO @ref sensor_sr04_gpio
 */
#pragma once

/** distance in mm once an echo has been received
 *  @note distance set 1 when the object is too near (no echo received)
 *  @note distance set UINT16_MAX when the object is too far (echo received to late)
 *  @warning to be clear by user
 */
extern volatile uint16_t sensor_sr04_distance;

/** configure MCU peripherals to communicate with HC-SR04 sensor
 */
void sensor_sr04_setup(void);
/** configure MCU peripherals used to communicate with HC-SR04 sensor
 */
void sensor_sr04_release(void);
/** trigger measurement
 *  @note the resulting measurement will be set in sensor_sr04_distance
 */
void sensor_sr04_trigger(void);