RFID or IR sensor better?

I was trying to do a small project which is to apply the hotel system key card where it open the door of a room and after enter the room we put it at a certain place where it acts as a switch for the lamp and aircond. So, i was wondering which one is better either using RFID or IR sensor?

There are advantages and disadvantages to each, but I think that the recent RFID chips provide alot of security, programmability and make the card simpler to design, make, and re-use.

Thank you for ur reply. If i want to use RFID do u know how to combine the circuit of lamp and aircond?? i only found how to use the rfid with 1 output. i was using the rfid with arduino. So far i can only make it to operate 1 output at a time but not both. Does any1 have a suggestion? (fyi: the lamp was represented with led while the aircond with computer cooling fan)

Unclear what you want to do with the card related to light and AC. The card has no buttons, so it can't be used as remote control.

A usual technique is to have a mechanical power switch activated for the room when the key card is stored in a respective holder. The operation is not specific to the type of card put in, and isn't needed to be.

Hi,
to act as a key to open the hotel room door: I recommend RFID.

IR needs some battery and is much bigger. I doubt you get this into a thin card.
The battery needs to be charged or replaced.

But for switching ON room power... I´d go FvM´s way: A simple switch that does not take care of card type or card code. Just mechanical.

I assume this all is avalilbale already. No need to design your own.

Klaus

It's standard in most hotels I've stayed at: RFID or magnetic stripe on the door lock and a card holder with a mechanical switch inside. It assumes you can't put the card in the holder if you couldn't get through the door! No need to use a second RFID reader or any software at all.

Brian.

Yup its the same with lots of hotel out there. What im trying to do is to implement the thing to my faculty. The requirement of the project is, it has to have sensors and microcontroller. So, i was just trying to make a prototype in a box or something which show the function not the actual thing. It just to solve the wastage of electricity when student or lecturer not in a room.

It souinds like what you need is a room occupancy sensor, something that tells you if there is someone inside the room rather than entering through a doorway with a security pass. RFID is unsuitable for this purpose because it's range is only a few cm, unless you use it to count people using the card to enter and leave the room.

IR sensors in a door frame will work, you use two emitters and two sensors with a space between them so you can detect which direction the interruption in the light beam is passing. The theory is you can count up the number of people entering and subtract the number of people leaving so you know if anyone is still inside. It is easy to fool though, for example what happens if you carry an object, for example a large box, with you as you enter and the system registers two people instead of one person. When you leave without the box it still thinks someone is left behind.

You could consider PIR sensors but they work on changes in radiated heat in different regions of their view so stationary people, say sitting in chairs or at desks tend to be ignored. The other alternative is a volumetric sensor, using either ultrasonics or microwaves. They are sensitive to tiny movement and maybe even air turbulence so they be a better way of checking.

Brian.