my hardware is working but on doing rostopic echo reading is 0.0

edit

Code below:

 /*
   rosserial PubSub Example
   Prints "hello world!" and toggles led
*/

#include <ros.h>
#include <std_msgs/Float32.h>
#include <std_msgs/Int32.h>
#include <Servo.h>
#include <dht11.h>
#define DHT11PIN 4
int pos = 0 ;
dht11 DHT11;
ros::NodeHandle  nh;
Servo myservo;
void messageCb( const std_msgs::Int32& movewiper) {
  if (movewiper.data == 1) {
    myservo.write(180);
  }
  else {

    myservo.write(0);
    delay(15);

  }
}

ros::Subscriber<std_msgs::Int32> sub("Servo", messageCb );

std_msgs::Float32 humidity_range;
ros::Publisher humidity("humidity", &humidity_range);

//char hello[13] = "hello world!";

void setup()
{
  myservo.attach(9); //tell the arduino where the motor is attached and to control it
  nh.initNode(); //for initializing
  nh.advertise(humidity);
  nh.subscribe(sub);
}

void loop()
{
  int chk = DHT11.read(DHT11PIN);

  if (DHT11.humidity > 60) {
    for (pos = 0; pos <= 180; pos += 1) {
      myservo.write(pos);
      delay(15);
    }
  }

  else {
    myservo.write(0);
    delay(15);
  }

  humidity.publish( &humidity_range );
  nh.spinOnce();
  delay(500);
}