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/****************************************************************************
*
* Copyright (c) 2014 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file sf0x_parser.cpp
* @author Lorenz Meier <lm@inf.ethz.ch>
*
* Driver for the Lightware SF0x laser rangefinder series
*/
#include "sf0x_parser.h"
#include <string.h>
#include <stdlib.h>
//#define SF0X_DEBUG
#ifdef SF0X_DEBUG
#include <stdio.h>
const char *parser_state[] = {
"0_UNSYNC",
"1_SYNC",
"2_GOT_DIGIT0",
"3_GOT_DOT",
"4_GOT_DIGIT1",
"5_GOT_DIGIT2",
"6_GOT_CARRIAGE_RETURN"
};
#endif
int sf0x_parser(char c, char *parserbuf, unsigned *parserbuf_index, enum SF0X_PARSE_STATE *state, float *dist)
{
int ret = -1;
char *end;
switch (*state) {
case SF0X_PARSE_STATE0_UNSYNC:
if (c == '\n') {
*state = SF0X_PARSE_STATE1_SYNC;
(*parserbuf_index) = 0;
}
break;
case SF0X_PARSE_STATE1_SYNC:
if (c >= '0' && c <= '9') {
*state = SF0X_PARSE_STATE2_GOT_DIGIT0;
parserbuf[*parserbuf_index] = c;
(*parserbuf_index)++;
}
break;
case SF0X_PARSE_STATE2_GOT_DIGIT0:
if (c >= '0' && c <= '9') {
*state = SF0X_PARSE_STATE2_GOT_DIGIT0;
parserbuf[*parserbuf_index] = c;
(*parserbuf_index)++;
} else if (c == '.') {
*state = SF0X_PARSE_STATE3_GOT_DOT;
parserbuf[*parserbuf_index] = c;
(*parserbuf_index)++;
} else {
*state = SF0X_PARSE_STATE0_UNSYNC;
}
break;
case SF0X_PARSE_STATE3_GOT_DOT:
if (c >= '0' && c <= '9') {
*state = SF0X_PARSE_STATE4_GOT_DIGIT1;
parserbuf[*parserbuf_index] = c;
(*parserbuf_index)++;
} else {
*state = SF0X_PARSE_STATE0_UNSYNC;
}
break;
case SF0X_PARSE_STATE4_GOT_DIGIT1:
if (c >= '0' && c <= '9') {
*state = SF0X_PARSE_STATE5_GOT_DIGIT2;
parserbuf[*parserbuf_index] = c;
(*parserbuf_index)++;
} else {
*state = SF0X_PARSE_STATE0_UNSYNC;
}
break;
case SF0X_PARSE_STATE5_GOT_DIGIT2:
if (c == '\r') {
*state = SF0X_PARSE_STATE6_GOT_CARRIAGE_RETURN;
} else {
*state = SF0X_PARSE_STATE0_UNSYNC;
}
break;
case SF0X_PARSE_STATE6_GOT_CARRIAGE_RETURN:
if (c == '\n') {
parserbuf[*parserbuf_index] = '\0';
*dist = strtod(parserbuf, &end);
*state = SF0X_PARSE_STATE1_SYNC;
*parserbuf_index = 0;
ret = 0;
} else {
*state = SF0X_PARSE_STATE0_UNSYNC;
}
break;
}
#ifdef SF0X_DEBUG
printf("state: SF0X_PARSE_STATE%s\n", parser_state[*state]);
#endif
return ret;
}
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