PIR+Relay Project using UNO....... help needed

Guys i am new to this awesome world of arduino, I have to do a project which is related to home automation... The requirements are, 1)the system should sense the presence of the individual in the space (room) 2)the system should turn on, and stay on till that individual is in the room 3)the system should turn off or not function when no one is there

guys for this i am planning to use uno,relay,pir sensor...i am using the relay to turn on the light...

any guidance, tips are welcome.....

Yes, you are in the right direction. The components that you have selected seams to be correct.

Here you have someone that have a problem like yours. He have selected already the Parallax PIR Motion Sensor. Take a look to this thread too.

luisilva: Here you have someone that have a problem like yours.

Probably in the same class....

Adafruit have a good tutorial which may help.

:)

2)the system should turn on, and stay on till that individual is in the room

That’s going to be a difficult requirement to meet with a motion sensor. If a person enters the room, and sits motionless, the sensor is going to quit reporting that the person is in the room.

PaulS…what to do for that particular problem?..

47aneeshwar:
PaulS…what to do for that particular problem?..

That depends on the (unstated) ultimate goal of the project.

If the idea is to turn the lights off when there is no one in the room, then turning them off if the person in the room fell asleep would not be a bad thing.

If the idea is to sound an alarm when there is a person in the room, it seems unlikely that a person would sit still long enough when the alarm was screaming to make the sensor quit recognizing him/her.

So, what is it you are trying to accomplish?

Well, you ask PaulS, but in my opinion if you want really do:

2)the system should turn on, and stay on till that individual is in the room

Maybe you need to sense the motion outside the room, and not inside the room, detecting the direction of the motion and understanding if the person is entering or leaving the room. This let you with many other problems, for example if 2 persons enters together and leaves separately. This will be my first approach for this problem. Note that you need more than one sensor to accomplish this approach.

BTW, do you have your ' . ' key of your keyboard broken?