Over the last couple of weeks I have been trying to design an auto start for my 1997 Isuzu Rodeo. The part I am having trouble with is interfacing the auto start to the car's starter. I didn't want to just take the dash apart and look around in it, I was hoping to find a diagram of the starter, however this search has been unsuccessful...
I have some knowledge of cars, but I am no expert. I can hook up the unlock/lock buttons easily enough, but I am afraid to mess with the starter until I have some basic information first. The first idea that comes to my mind is to get some relays between the power to the ignition and do it that way...but I wasn't quite sure if that was the right thing to do, although it seems that's the way industry auto starters work.
Thanks for that info, that's exactly what I needed!
I was wondering if anyone could tell me how exactly I hook these relays up, because I don't know if I know how to...I figured it would be something like:
At least I think that's what I am supposed to do. So looking at this would I put a relay on:
Starter
Ignition 1
Ignition 2
Accessory
Trunk Pin
Door Trigger
Door Lock
Door Unlock
Also I would need a sensor on the brake switch to tell me if the brake was being pressed, and another sensor to see if the key's position is in the right position (this way if you try and shift while the key isn't in the car, I can tell it to shut off as a safety feature). I am not quite sure how to do this either. Would I just use two more relays except hook them up opposite to what I already have (have the arduino wires on the 30, 87a, and 87; and have the sensor/switch on the 85 and 86 pins?
I'm just a little confused at the moment on where to start with this. I figured this would be the easy part and the RF transceiver would be hard part, but the RF transceiver took all of 5 minutes to get up and running, and this relay business is hurting my head... :o
I do not have any proof that I will definitely not harm or kill anyone with the vehicle, period. I could just go crazy tomorrow and hit everyone I see... But even with these modifications there are three probable outcomes that are possible:
The car doesn't start
The car won't turn off
The car turns off
In either of those three cases there is no possible chance that I can hurt anyone, well unless my brakes stop working...but since what I'm doing has no connection to the brakes that would be bad even without the modification...
Motors 1 thanks to grumpy mike's page, theres a pretty good lesson on interfacing relays to the arduino. also, you might want to include some sort of detection to make sure the car is out of gear when you start. that way if it was in gear and something went wrong you wouldnt having a rolling massacre.
First, let me just add some possible car states to the (oversimplified) situation you described: the car is running, and the car is not running.
The car is running and:
the car won't turn off. If you are in motion this is probably what you want. If it's not in motion probably a small annoyance.
the car turns off. If you are in motion you loose your brakes and steering. Let's say you are on the highway, doing 120km/h (~75mph). The brakes are enough for you to slow down to only so much and the steering is lost. You can check it yourself how that feels. If you are not in motion then a small annoyance.
the car doesn't start. If the car is not in motion - small annoyance. If the car is in motion, I don't know how you got to the point, but probably the annoyance is slowly turning into minor trouble.
I didn't even bother adding the complications if it's a manual. (Think about it - it starts when you or a kid is standing in front of it, not inside)
Anyway - just look around the internets and see if you find ANY tutorial that deals with deadly AC power that does not have HUGE disclaimers plastered over it. The idea is that though it is definitively proven that AC will kill if you touch it, people get killed, and presumably people that know how to handle AC. This is a single factor - you touch it - it kills you. With a vehicle so many things can go wrong.
So basically there is the (moral) factor that anybody that helps you is partially your accomplice, if anything goes wrong.