I was wanting to start experimenting with a key fob using for use in some remote project (in case you don't know what a key fob is like I didn't, its the little remote you use to unlock/lock your doors on your car...).
I'm not quite sure if I can just use any fob around with the arduino, so I thought I would come here and ask. In walmart there are several generic aftermarket electronic key fobs, can I use these? If so can anyone point me in the direction of a receiver of some kind? I also was looking around and came across this key fob:
I like this one because it can be used with a generic transceiver:
But the one thing it lacks is security. I was hoping to have some sort of security on the thing like a garage door opener has (or, even better, like a car has). But I pretty much only know the basics of these things, and I'm hoping someone can feed me some information of some sort. :o
The transmitter and receiver can be set to use any one of 256 security codes to avoid interference and unintentional activation. Security codes also allow you to have multiple receivers respond to the same transmitter or multiple receivers only respond to specific transmitters. A receiver will ONLY respond to a transmitter with the same security code.
One important question you need to answer is how "remote" your project is: the range you need will be a big faction in deciding which one to use.
Also, does it really need to be a "key fob"? I.e., will you really carry it around on your key ring all the time? Or does it just need to be "compact"? I think that ebay unit knuckles pointed out might be a little large. Which could be either a blessing (if the size enables you to use a cheaper/longer-lasting battery and/or get better range) or a curse (if you like wearing really tight pants to the disco :))
Just to butt in, I have two of those eBay units. I use one as a remote MIDI event generator. The other unlocks my car! The fobs are smaller than they look; when I go to the gym, I lock my car keys in the car and just stick the fob in my pocket.
Practical range, though, is under forty feet. I've been able to get a signal at 60-plus feet, but not consistently. It also takes about half a second to wake from sleep mode when you first press a button. So best for simple, not time-critical stuff at limited ranges.