Virtual Sensor implementation in Contiki NG OS

Native Temperature, Humidity and Pressure Sensor in Contiki NG 

Implementation of Three sensors namely temperature, humidity and pressure sensor in contiki NG OS.

We need four files namely

Step 1: Create a Folder called temperature/ in the folder contiki-ng/examples/

and then copy paste the following four files to the above folder.

// mytemp.h

#ifndef MYTEMP_H

#define MYTEMP_H

struct Sensor {

 char name[15];

 float value;

};

struct Sensor read_temperature();

struct Sensor read_humidity();

struct Sensor read_pressure();

#endif

// mytemp.c

#include "mytemp.h"

#include <string.h>

#include <stdlib.h>

float random_value(float min, float max)

{

 float scale = rand() / (float) RAND_MAX;

 return min + scale * (max - min);

}

struct Sensor read_temperature()

{

 struct Sensor temp;

 strncpy(temp.name, "Temperature", 15);

 temp.value = random_value(0, 35);

 return temp;

}

struct Sensor read_humidity()

{

 struct Sensor humdidty;

 strncpy(humdidty.name, "Humidity", 15);

 humdidty.value = random_value(40, 80);

 return humdidty;

}

struct Sensor read_pressure()

{

 struct Sensor pressure;

 strncpy(pressure.name, "Pressure", 15);

 pressure.value = random_value(30, 78);

 return pressure;

}

// demo.c

#include "contiki.h"

#include "sys/etimer.h" //etimer Event Timer

#include "mytemp.h"

#include <stdio.h>

PROCESS(sensor_process, "Sensor process");

AUTOSTART_PROCESSES(&sensor_process);

static struct etimer timer;

PROCESS_THREAD(sensor_process, ev, data)

{

 PROCESS_BEGIN();

 printf("Native Sensor\n");

 

while(1) {

 etimer_set(&timer, CLOCK_SECOND*2);

PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&timer));

 struct Sensor temp = read_temperature();

 printf("%s: %.2f\n", temp.name, (double)temp.value);

 struct Sensor hum = read_humidity();

 printf("%s: %.2f\n", hum.name, (double)hum.value);

struct Sensor pressure = read_pressure();

 printf("%s: %.2f\n", pressure.name, (double)pressure.value);

  

printf("------------\n");

 }

 PROCESS_END();

}

#Makefile

CONTIKI_PROJECT = demo

all: $(CONTIKI_PROJECT)

PROJECT_SOURCEFILES += mytemp.c

CONTIKI = ../../

include $(CONTIKI)/Makefile.include

To run this File

Open a Terminal  and go to contiki-ng/examples/temperature/

$] cd contiki-ng/examples/temperature

$] make TARGET=native 

$] ./demo.native

Please see the screenshot below:

Sensors in Contiki NG

Sensors in Contiki NG