82 lines
1.6 KiB
C
82 lines
1.6 KiB
C
/*
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* cm_nmea_decoder.c
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*
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* Created on: 26 Jun 2025
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* Author: Christian Lind Vie Madsen
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*/
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#include "cm_nmea_decoder.h"
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#include <stdlib.h>
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#include <string.h>
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#define MAX_NMEA_MSG_TYPES 2
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const char *nmea_msg_types[MAX_NMEA_MSG_TYPES] = {"$GPGLL", "$GPGFF"};
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typedef int (*nmeaDecoder_Evt_fpt)(cm_nmea_msg_t *inst, char *str);
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static int findLenToChar(const char *str, const char character){
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int i = 0;
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while((str[i] != character) && (str[i] != '\0')) i++;
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return i;
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}
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static int sGPGLL_decode(cm_nmea_msg_t *inst, char *str){
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//Move pointer until we meet a "," or NULL!
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while((str != NULL) && (*str != ',')) str++;
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// Move past ','
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if (*str == ',') str++;
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// Find comma
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int comma_idx = findLenToChar(str, '.');
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// Replace with '\0'
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str[comma_idx] = '\0';
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// Decode first part of latitude
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inst->gpgll_msg.coordinates.deg = atoi(str);
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printf("deg: %d, str: %s \r\n ",comma_idx,str);
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return 0;
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}
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nmeaDecoder_Evt_fpt nmea_decodeFuncs[1] = {
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(void *)&sGPGLL_decode,
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};
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static int sNMEA_getMsgType(char *str){
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for(int i = 0; i < (MAX_NMEA_MSG_TYPES-1); i++){
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if(strcmp(nmea_msg_types[i], str)) return i;
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};
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return -1;
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}
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int cm_nmea_characterDecode(char in){
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return 0;
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}
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// This function returns the message type, so the user knows which message has been decoded!
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int cm_nmea_stringDecode(cm_nmea_msg_t *inst, char *str){
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// Find which type of message we need to decode.
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int nmea_msg_idx = sNMEA_getMsgType(str);
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// Check if we found a valid NMEA message.
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if(nmea_msg_idx == -1) return nmea_msg_idx;
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// Use the correct function to decode!
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if(nmea_msg_idx >= 0) nmea_decodeFuncs[nmea_msg_idx](inst,str);
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return nmea_msg_idx;
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}
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