diff options
Diffstat (limited to 'src/drivers/sf0x/sf0x_parser.cpp')
-rw-r--r-- | src/drivers/sf0x/sf0x_parser.cpp | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/drivers/sf0x/sf0x_parser.cpp b/src/drivers/sf0x/sf0x_parser.cpp new file mode 100644 index 000000000..8e73b0ad3 --- /dev/null +++ b/src/drivers/sf0x/sf0x_parser.cpp @@ -0,0 +1,155 @@ +/**************************************************************************** + * + * 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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