Led.c

#include "contiki.h"
#include<stdio.h>
#include "dev/leds.h"

#include "dev/button-sensor.h"

PROCESS(led_process, "LED process");

AUTOSTART PROCESS(&led_process);

PROCESS_THREAD(led_process,ev,data)
{
PROCESS_BEDIN();
SENSOR_ACTIVATE(button-sensor);

while(1)
{
  printf("Press button Sensor\n");
  PROCESS_WAIT_EVENT_UNTIL(ev=sensors_event && data = button_sensor);
  leds_toggle(LEDS_GREEN);
printf("Sensor value is %u",leds_get());

PROCESS_END();
}