Designing a DIY Wireless Car Remote: Steps and Resources

[hardyboy16jm]

First of all, I'm sorry if I posted this in the wrong place or if this question is so bad that you had to spit at your computer, but I'm not really sure how to start this project.

Ok, so I have my 1999 Honda which doesn't have a remote to unlock/lock the doors. So I want to make one. It'll be like a normal car remote, but instead of the lock unlocking/locking like magic, I think it'll be easier to just make a little arm the clamps to the lock and unlocks/locks it. I have no experience in engineering (however I am a hobbyist programmer, if that helps), but that's what makes it fun. So I have a few questions:
-What (in your opinion) will be the main steps in creating this remote?
-What do I need to learn to make this?
-Where can I find material with this information? (I'd rather just have free info off the internet, but I'm open to buying books if necessary)
Thanks in advance! And please only give helpful answers, I hate when people say I can't do it or just tell me to buy one.

 

[Danger]

I assume that this thing doesn't already have electric locks. Your idea really would be easier than installing such inside the door panel. Please describe the lock button: rocker, vertical push/pull, horizontal or vertical slider, etc.. In any event I would recommend a lead screw (also called a screwjack) system because it gives a lot of force and I know as a locksmith that some of those suckers are pretty hard to move, particularly in winter when any present lubricants stiffen.
I know nothing about electronics, so you'll have to wait for someone else on that matter.

 

[etudiant]

What are you trying to do exactly? A diagram would really help.
Your description is difficult to understand. Is there something missing here:
'instead of the lock unlocking/locking like magic, I think it'll be easier to just make a little arm the clamps to the lock and unlocks/locks it'

 

[256bits]

Your project needs a transmitter, a receiver and an acctuator. The transmitter will be the item to carry with you, and by the press of a button, a signal can be sent that the receiver on the car can pick up to activate the actuator,

You have to choose what type of signal and its format to communicate between the transmitter and receiver. RF(radio frequency), infrared, laser or ultrasonic could be some choices. You might even decide to use a water pistol to shoot a stream of water at a target on the car to activate your lock.

There are certain legal rules to follow in regards to the transmitter.
RF is limited to certain bands and power output, and should not cause unwanted interference with other electronic equipment in the vicinity. For example, sending a RF signal on a frequency used by the AM radio, could cause a buzz for listeners who will say "what the frack" was that before they forget about it in 3 seconds. The FCC in the US doesn't like people to do that sort of thing.

for laser, you definitely do not want to go over a certain wattage so you do not burn the eyeballs out of inmocent people nearby.

You select a certain signal frequency and modulation, or code it, so that only your transmitter can open the locks. If you select laser, you would not want anyone else with a pen laser to be able to open your car.

AM and FM are 2 two types of modulation that we mostly hear about. Since you are a hobby programmer you might find this interesting about hard disks and floppies http://en.wikipedia.org/wiki/Modified_Frequency_Modulation

You can check ot how your TV remote uses infrered and the signals used to communicate to the TV, Or investigate remote controlled airplanes and the RF communication used there.

You could keep in somewhat simplier by just having the receiver recognize on/off input from the transmitter such as something like the famous Morse code, or even simpler such as a number of presses of the button on your transmitter are needed to open the locks.

That is it for now.

 

[hardyboy16jm]

Thank you 256bits, your post was really really helpful and has led me to a lot of research on RF communication. Many many thanks!

 

[pantaz]

I can appreciate the desire to do it all yourself, but it sounds like you want a working device pretty soon. You can buy this complete kit for under $20 -- http://www.allelectronics.com/make-a-store/item/RC-10/KEYCHAIN-REMOTE-CONTROL-12VDC-6-AMP/1.html

(I'm not affiliated with the company, I'm just a long-time customer.)