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.