any sensor that sense human...

is there any sesnor that sense human? i asked many people they said use PIR sensor but PIR sensor detect movement i dont want this i want a sensor that only sense human??

I know of no sensor that can tell the different between a human and any other large primate.

What are you doing that a PIR wouldn't work? All of the humans I know, move.

my project is like when sensor detect human in the room aricon should turn on and when there is no one in the room aircon should turn off but i m using PIR sensor and in PIR sensor we have to put time like delay(4000); so after 4 minutes it detect again, can i do something in which aircon keep turn on until human dont leave the room....?

There is no easy way to do this.

You could use a webcam, a Kinect or a thermal camera. And use recognition software to see if it is a person. That are large projects.

Or you can do what commerical systems do... Use a PIR. If there is no movement for 10 or 15 minutes, they shut off the A/C.

Don't double post.

http://arduino.cc/forum/index.php/topic,104538.0.html http://arduino.cc/forum/index.php/topic,104541.0.html

is there any way that PIR keep sesning movement? like as u said after 15 minutes it will detect again and if he detect movement it will turn off aircon and then turn on again...???

Each time the PIR sees movement, reset a timer.

can u tell me how to reset timer?

unsigned long lastMovement = 0;

Every time the PIR reports movement:

lastMovement = millis();

On each pass through loop:

if(millis() - lastMovement >= (15000UL * 60UL))
{
   // No movement for 15 minutes.
   // It's lights out
}

u could use a NDIR CO2 sensor, since u need to know air quality anyway... http://en.wikipedia.org/wiki/CO2_sensor#Nondispersive_Infrared_.28NDIR.29_CO2_Sensors