Car door unlocking

Is the arduino capable of functioning as multiple key fobs (car lock/unlock remote thingy) with just the resonator from a spare key fob and some clever programming?

I'm kind of a newbie at radio control so please let me know if I'm completely off base

You want to collect cars from all over the country ?

What do mean by resonator ?
You could mimic the buttons with by soldering reed relais parallel to the buttons and use the Arduino to activate the buttons.

Modern cars have a encryption code in both the key and the car. If you have an older car without that, you have to use extra precautions.

Perhaps you're looking for something like this? iFOBing A Mazda - SparkFun Electronics

linucksrox:
Perhaps you're looking for something like this? https://www.sparkfun.com/tutorials/135

This project is pretty much what I am trying to accomplish, but I am strapped for cash and trying to get away with part I have on hand.
My work around idea is to use the resonator out of a key fob I found and some clever programming to get my Arduino to work as an off the shelf key fob that you can train your vehicle to respond to.

I'm looking for info on how the rolling code encryption is preformed (preferably some source code) and how to hook up a resonator. I've looked at a couple of tutorials on using a resonator and they appear to have contradicting information.

threadz:
I'm looking for info on how the rolling code encryption is performed (preferably some source code)

XD XD XD XD XD

Caltoa:
You want to collect cars from all over the country ?

Not really. I can only use one at a time anyway.

Caltoa:
What do mean by resonator ?

That's what the datasheet called the part that is referred to as the transmitter in tutorials for increasing the range of your key fob. I'm rather unclear as to exactly what it does.

Caltoa:
You could mimic the buttons with by soldering reed relais parallel to the buttons and use the Arduino to activate the buttons.

I was thoroughly unable to solder wires to these contacts, or any of the other parts which they were connected to via traces

I'm looking for a way to get an Arduino to emulate the function of an off the shelf key fob - the kind that you can program your vehicle to respond to - using as few parts as possible as my budget is tight right now.

Paul__B:

threadz:
I'm looking for info on how the rolling code encryption is performed (preferably some source code)

XD XD XD XD XD

I don't expect Arduino specific source code, but the math behind the encryption probably exists in C/C++ somewhere.

When the encryption is done well, the source code is useless.

For a good encryption the key would need a good randon generator. Then next transmitted code depends on the previous codes. The car would know that it depends on the previous codes. Since you don't know where in that stream of codes the key and the car are, you can not know what the next code will be.

You can try to break that, and there are specific procedures for some cars. Do you really want me to write here the word "jail" ?

I think the "resonator" is a bad automatic translation from chinees to english. Since the key itself can be "key" or "transmitter" or "remote key" and so on.

threadz:
I don't expect Arduino specific source code, but the math behind the encryption probably exists in C/C++ somewhere.

Lotsa luck!

Not only myself, but a few thousand people would be most interested in it.

Surprising new: I found the keeLOQ cipher (the one standard to key fobs) source code on a blog-type thing from the middle ages.
http://www.pittnerovi.com/jiri/hobby/electronics/keeloq/
Better yet, the code will compile for my Arduino Leonardo processors if you add 4 lines to the header file:

typedef unsigned long long uint64_t;
typedef unsigned long uint32_t;
typedef unsigned int uint16_t;
typedef unsigned char uint8_t;

I also found out that there are ICs that do all the ciphering and PWMing for you, such as the HCS300 (http://ww1.microchip.com/downloads/en/DeviceDoc/21137G.pdf).
I'll probably just order one of these to make my project easier.