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https://github.com/RIOT-OS/RIOT.git
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88 lines
2.1 KiB
C
88 lines
2.1 KiB
C
/*
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* Copyright (C) 2014 Hamburg University of Applied Sciences
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*
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* This file is subject to the terms and conditions of the GNU Lesser General
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* Public License v2.1. See the file LICENSE in the top level directory for more
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* details.
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*/
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/**
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* @ingroup driver_srf02
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* @{
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*
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* @file srf02.c
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* @brief Driver for the SRF02 ultrasonic ranger.
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* The connection between the MCU and the SRF02 is based on the
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* i2c-interface.
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*
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* @author Zakaria Kasmi <zkasmi@inf.fu-berlin.de>
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* @author Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
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*
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* @}
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*/
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include "msg.h"
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#include "vtimer.h"
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#include "timex.h"
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#include "thread.h"
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#include "hwtimer.h"
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#include "srf02.h"
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#include "periph/i2c.h"
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#define ENABLE_DEBUG (0)
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#include "debug.h"
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int srf02_init(srf02_t *dev, i2c_t i2c, uint8_t addr, i2c_speed_t speed)
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{
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dev->i2c = i2c;
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dev->addr = addr;
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/* initialize i2c interface */
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return i2c_init_master(i2c, speed);
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}
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uint16_t srf02_get_distance(srf02_t *dev, srf02_mode_t mode)
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{
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int status;
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char range_high_byte = 0;
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char range_low_byte = 0;
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uint16_t distance = 0;
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/* initialize measure mode*/
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status = i2c_write_reg(dev->i2c, dev->addr, SRF02_COMMAND_REG, mode);
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if (status < 0) {
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DEBUG("Write the ranging command to the i2c-interface is failed");
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uint16_t distance = UINT16_MAX;
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return distance;
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}
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hwtimer_wait(70000);
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status = i2c_read_reg(dev->i2c, dev->addr,
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SRF02_RANGE_HIGH_BYTE, &range_high_byte);
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if (status < 0) {
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DEBUG("Read the high echo byte from the i2c-interface is failed");
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distance = UINT16_MAX;
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return distance;
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}
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status = i2c_read_reg(dev->i2c, dev->addr,
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SRF02_RANGE_LOW_BYTE, &range_low_byte);
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if (status < 0) {
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DEBUG("Read the low echo byte from the i2c-interface is failed");
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distance = UINT16_MAX;
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return distance;
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}
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distance = (range_high_byte << 8) | (range_low_byte);
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return distance;
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}
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