srf02.h
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/*
* Copyright (C) 2013 Zakaria Kasmi <zkasmi@inf.fu-berlin.de>
* 2015 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @defgroup drivers_srf02 SRF02 ultrasonic range sensor
* @ingroup drivers_sensors
* @brief Driver for the SRF02 ultrasonic range sensor
* @{
*
* @file
* @brief Driver definitions for the SRF02 ultrasonic ranger.
*
* @author Zakaria Kasmi <zkasmi@inf.fu-berlin.de>
* @author Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*/
#ifndef SRF02_H
#define SRF02_H
#include <stdint.h>
#include "periph/i2c.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Default I2C address of SRF02 sensors
*/
#define SRF02_DEFAULT_ADDR (0xe0) /* 224 decimal */
/**
* @brief The datasheet tells us, that ranging takes 70ms
*/
#define SRF02_RANGE_DELAY (70000U)
/**
* @brief Device descriptor for SRF02 sensors
*/
typedef struct {
i2c_t i2c; /**< I2C device the sensor is connected to */
uint8_t addr; /**< I2C bus address of the sensor */
} srf02_t;
/**
* @brief Possible measurement modes of the SRF02 sensor
*/
typedef enum {
SRF02_MODE_REAL_INCH = 0x50, /**< result in inches */
SRF02_MODE_REAL_CM = 0x51, /**< result in centimeters */
SRF02_MODE_REAL_MS = 0x52, /**< result in microseconds */
SRF02_MODE_FAKE_INCH = 0x56, /**< result in inches (no pulse send) */
SRF02_MODE_FAKE_CM = 0x57, /**< result in cm (no pulse send) */
SRF02_MODE_FAKE_MS = 0x58 /**< result in ms (no pulse send) */
} srf02_mode_t;
/**
* @brief Initialize the SRF02 ultrasonic sensor
*
* @param[in] dev device descriptor of an SRF02 sensor
* @param[in] i2c I2C device the sensor is connected to
* @param[in] addr I2C address of the sensor
*
* @return 0 on successful initialization
* @return -1 on error
*/
int srf02_init(srf02_t *dev, i2c_t i2c, uint8_t addr);
/**
* @brief Trigger a new measurement
*
* This function triggers a new ranging operation. After triggering this
* operation, you have to wait at least 70ms for the result to be ready.
*
* The result of the ranging operation is returned in inches, centimeters or
* microseconds - depending on the given @p mode parameter.
*
* @param[in] dev device to trigger
* @param[in] mode there are three real ranging modes, which return
* the result in inches, centimeters or microseconds.
* Another set of three fake ranging modes do the same
* but without transmitting the burst
*/
void srf02_trigger(const srf02_t *dev, srf02_mode_t mode);
/**
* @brief Read the results of the last ranging operation
*
* @param[in] dev device to read from
*
* @return result of the last ranging operation, meaning depends on the mode
* parameter given to the srf02_trigger function
*/
uint16_t srf02_read(const srf02_t *dev);
/**
* @brief Get the distance measured from the SRF02 ultrasonic sensor
*
* This function combines the srf02_trigger and the srf02_read functions for
* simplified usage in simple (single sensor) setups.
*
* @param[in] dev device descriptor of an SRF02 sensor
* @param[in] mode there are three real ranging modes, which return
* the result in inches, centimeters or microseconds.
* Another set of three fake ranging modes do the same
* but without transmitting the burst
*
* @return the ranging result in inches, centimeters or microseconds
*
*/
uint16_t srf02_get_distance(const srf02_t *dev, srf02_mode_t mode);
/**
* @brief Program the given device with a new bus address
*
* @param[in] dev device to program
* @param[in] new_addr new address to program the given device to
*/
void srf02_set_addr(srf02_t *dev, uint8_t new_addr);
#ifdef __cplusplus
}
#endif
#endif /* SRF02_H */
/** @} */