NOTE: This is an old article. Please go to the Meshlium development section in order to get the latest tutorials.

Parsing Sensor Frames

This code example has been tested and improved to be executed in Meshlium with the data coming from a Wireless Sensor Network created with Waspmote.


This program reads through the standard input and parses strings received.

For this example the frame will have this structure:


ID_<mote>#Sensor_value


A valid frame can be:


ID_12#239



The objetive os this tutorial is to provide a basic example for frame parsing.


File:
"basic_parser.c"

Compilation on Meshlium:
gcc basic_parser.c -o basic_parser

Usage:
basic_parser

Note:
This code works at 19200 bauds, you can change it on code. Just look for string B19200 and replace 19200 with the speed you need.


Code



/*
 *  Copyright (C) 2008 Libelium Comunicaciones Distribuidas S.L.
 *  http://www.libelium.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  Version 0.1
 *  Author: Octavio Benedi Sanchez
 */


#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <termios.h> /* Terminal control library (POSIX) */
#include <ctype.h>



#define MAX 500
#define MAX_SQL 700

main(int argc, char *argv[])
{
 	int j=0;
	int ret;
	int mote_id;
	int sensor_value;
	char valor[100];
	char c;
    while(1)
    {
        read(0,&c,1);
	fprintf(stderr,"%c",c);
        valor[j]=c;
        j++;
        if((c=='\n') || (j==(99)))
        {
		valor[j]='\0';
		ret=sscanf(valor,"ID_%d#%d",&mote_id,&sensor_value);
		if (ret==2)
    		{
			fprintf(stderr,"%s\n%d\n%d\n%d\n",valor,mote_id,sensor_value,ret);
		}
		else
		{
			fprintf(stderr,"%s\n%d\n%d\n%d\n",valor,mote_id,sensor_value,ret);
			fprintf(stderr,"Bad frame\n");
		}
		j=0;
		valor[j]='\0';
        }
    }
}

Download code

You can download the code of this tutorial.


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