Recently I added a remote start to my car. All is good in the world. Unfortunately, I work at an airport and my car is about a 15 minute shuttle ride from my office. There is not much opportunity to ‘stand at the door and wait for warm car’ there.
But cruising the web, I happened upon the Viper website, where I read about a new system where you can start your car via an iPhone from virtually anywhere. After looking into the system, I soon stumbled onto the fact that the system is ridiculously expensive, as is everything that has to do with the Godforsaken iPhone newer technology. Further research on the subject yielded little hope, as all other systems were out of my budget (cheap as heck).
My co-worker and I started daydreaming on the subject (what goes on at an airport that we would need to pay attention?) When I stumbled on an idea. My remote start has a wire called the Remote Start Activation Input. Now the job of the RSAI is, from the manual: “This wire will start the vehicle when it sees two negative pulses. Only used when incorporating into existing alarm or FOR TESTING PURPOSES.” That last part I capped and bolded, as that is what is most important for me. “Testing” consists of simply grounding that wire for two pulses in order to start the car. Two more pulses shuts it down, exactly like using the remote.
Bingo, I had my way in! Here is what I came up with:
I hope you can tell what is going on there. If not, here is a synopsis, and a little bit of method behind my madness…
The remote start requires 2 pulses within 3? seconds to initiate the remote start sequence. So how to send those 2 pulses? Easy, I remove the vibrate motor from a cell phone or pager and use that circuit to initiate the remote start by setting the phone to vibrate. But wait…the RSAI only works when put to ground, that circuit has (after testing) a 1.35v current. I guess I have to use a relay! Oh no…The remote start turns off after 2 MORE pulses. How do I get the cell phone to STOP sending rings? Hrm…
The answer came from beegbie over at the12volt.com. The remote start start up sequence goes like this. Sense Input>Turn on Accessories>Try to Crank Engine. If I put a normally closed relay on the vibrate circuit triggered by the vehicle accessory circuit, then once the remote start sequence kicks off, any subsequent rings by the phone won’t be ‘heard’ by the remote start.
Whew!
Here are some pictures of the tear down and modification of the cell phone:
Purchased this phone for $10 from CVS Pharmacy along with $20 worth of prepaid minutes. Phone came with a battery and wall wart charger.
Removed the 6 tri-wing (fail) screws holding the inner bezel on. Once off, all the goodies are revealed. You can remove the PCB fairly easily, but for the most part it is single sided.
Here I have already removed the vibrate motor and soldered wired back into it’s place. I wanted an easy way to remove the phone if I needed to make any modifications to it or add minutes, or hell, even make an emergency phone call. I decided on desoldering the headphone jack from and isolating it with that paper stuff I got from another board. I glued the paper down, then glued the jack to it. Then I soldered the pins that correlate to the 2nd & 3rd pins on the headphone jack to the wires coming off the vibrate motor resistors. I chose (had no choice) to solder the wires to the resistors due to me tearing out the traces on the pcb when removing the motor. I was a little skittish applying the amount of heat required to remove that bish, thinking I might desolder some of the tiny little components around it. Also of interest to some would be my choice of wire. That is two strands from a IDE connector. One is marked to denote it’s polarity. (It helped, really.)
Here is a picture of the headphone jack lookin’ all normal and stuff. I like a nice clean install. This way the phone loses only the functionality of vibrate and using a headset. I can still set the ringer, make calls, etc.
Here is the modified headphone jack for the hookup. This is a 2.5mm (mini) headphone jack that I had from a cheap headset from another phone. The wires were those damned coated wires, and quite puny at that, so I cut apart the boot and desoldered them at the source. I then removed 2 wires from a 10ft piece of cat5e and soldered them in place, shrink wrapped and Bob’s yer uncle. Why, you should ask, did I use Ethernet cable. Several reasons: It is sturdy, it was solid not stranded, I could pick my length and I have about 300 feet in a box behind me.
All in all I think the thing may actually work. I need to source some cheap solid state relays that initiate below 1.5 volts. I am also thinking about maybe using an optoisolator, as I have 2 in a scavenged pcb beside me that are in the correct voltage range. I will still need a 30A auto fuse for the other relay, though. I have a breadboard on order from Sparkfun that should come in handy for testing.
The best part of this project are the possibilities. Not only can I remote start my car from afar, I can also use the other features of the phone to automate the remote start. I can set up to 4 alarms on this phone, and set them to vibrate. Since I work 4×10 shift, that is perfect for starting my car everyday before work. Also, that phone has a timer on it that can also trigger the vibrate function. Haven’t figgered out a practical use for that yet. But the Pièce de résistance is the Calendar. I can set nearly unlimited events into the calendar, and set an alarm to trigger the vibrate at or before the event in 15 minute intervals. I can also set the as ‘recurring events’, too. I could program in mine and my wife’s work schedules, upcoming doctors appointments, ANYTHING! Not bad for a $10 phone. I am glad that I decided to make the phone easily connect/disconnectable.
Check out Part 2 to see if I can actually pull it off.
January 23rd, 2010 on 10:26 AM
Why not just set the phone to activate the normal remote starter activator.. ie the one that you would normally press to start the car? seems like that would cut our a lot of fussing
January 24th, 2010 on 7:17 AM
Because that would involve tearing apart a remote fob and dissecting the internals. The remote starter module already has a wire made to interface with an accessory. I just tapped into that.
January 26th, 2010 on 2:33 AM
Did you ever check to see if there was enough voltage on audio jack to trip (momentary) a relay?
January 26th, 2010 on 5:16 AM
Yes I did, however the voltage constants were al over the place, so I could not get a stable enough signal to trip the relay consistently.
January 26th, 2010 on 10:26 AM
Completely I share your opinion. In it something is and it is excellent idea. I support you.
February 1st, 2010 on 10:54 AM
Your cell phone is amazing starter, but I do not understand this lack of explanation is this guy have to do relays il203 When making one’s cell phone to the earpiece of the other two lines must be connected to one where
5 relays, each relay pinrilreinga line which connected up the wrong night, and someone wondered if the phone do not start to take a quick dapbyeonjom bappeugetjiman send email to splittin ‘Well, this is Korea, I do not know English, translator, please send e-mail using Rodapjangjombaranda
February 6th, 2010 on 4:21 PM
All this work so that you can start your car 15 minutes earlier when you come 1 a month from the airport…. wow.
February 9th, 2010 on 2:02 PM
I work at the airport, Jackass. I’m there every day (almost). That 15 minute tram ride get old after 11 years. Come to think of it, that is 42,900 minutes I have wasted on that thing. And you think it’s idiotic that I start my car while I’m on the shuttle rather than wasting another 5-10 minutes in the freezing cold waiting for it to warm up?
What school taught these people reading comprehension?
February 6th, 2010 on 5:49 PM
To do this you’d have to buy minutes, and even Virgin mobile minutes expire every month if you don’t buy more unless you buy special cards that cost more. To my knowledge the lowest plan/prepaid card from virgin mobile is $20. So you’re paying $20 every month for this car starter. The alternative would be to get a text only plan from virgin mobile and pay $15 each month, but that’s still a lot, reaching $180 in a year.
If minutes never expired, this solution would be fantastic. Unfortunately today’s cell phone companies have us by the balls and there isn’t really an option but to pay every month or lose your minutes.
February 9th, 2010 on 1:58 PM
Amen. You could pay the $90 premium that lets you keep your minutes for a year, then just buy one $20 card. That is $110/year. Cheaper still, but still not cheap.
February 7th, 2010 on 6:42 AM
can you also stop the car’s engine as well? that’d be great if your car is stolen.
Thanks for the cool projects though 😀
February 9th, 2010 on 1:51 PM
I have thought of that, but I don’t think I am going to include it for security reasons. 70mph on the hwy and being unplugged on accident is not cool.
February 7th, 2010 on 1:28 PM
Hey,
Funny thing, imagine you have forgotten your mobile phone at home and you are driving somewhere. If your wife/kid/dog takes your phone and dials that number, would the car then shut down? )))))
Anyway, nice idea, thanks for sharing.
Cheers
February 9th, 2010 on 1:46 PM
No, it wouldn’t (silly). The remote start functions per normal, and the second relay cuts of the phone from the system. Also, once you hit the brake, the remote start is deactivated and the car functions as normal.
February 8th, 2010 on 4:00 PM
I don’t mean to troll at all, it’s a legit concern: Does your prepaid phone carry-over minutes? If not you might have to put a few bucks on the phone every month.
Brilliant idea. I might try this when it gets warmer out.
February 9th, 2010 on 1:42 PM
It does not carry over minutes, unless you pay a premium. That is why I would suggest NOT going with Virgin mobile. I have let my plan expire and am just using the scheduler function to start my car, which is working out BRILLIANTLY!
February 10th, 2010 on 12:50 AM
Couldn’t just txt you phone? According to the Virgin mobile’s website, payasyougo txts are only 15 cents. So, you’d just pay 15 cents every time you want to start you car. (unless VM has free incoming, or you have to have a card just to receive txts)
Anyways, I can’t wait to install this on my Catera!
February 8th, 2010 on 7:05 PM
Very good information thank you.
Bookmarking this page.
February 8th, 2010 on 10:03 PM
I would have used an 8870 IC and a PIC with the phone on auto answer so that a code would be required to start the car. I’d hate for my car to start every time I got a wrong number. A ready-made board for this can be purchased from Motron or a similar company if circuit design is not your thing.
February 9th, 2010 on 1:40 PM
That is just what I am looking into. Now to find the time…wish I could write a hack to find more time…
February 18th, 2010 on 3:52 PM
I agree with your concerns about the advisability of being able to shut down the car remotely. I would NOT like to be behind a vehicle at 50+mph and have it come to a sudden stop in front of me!
Having said this, assume that you surrender your car, keys and all, under threat from an armed individual.
IF and it’s a big if, you were able to follow your car at a safe distance or visually as it disappears down the street and call it from a cell phone (not even your own if the bad guy took it) and shut it down?
I would definitely be in the market for a kit that could do this. Yes, there is a commercial product on the market (GSM REMOTE CONTROL SWITCH), but hey, let’s support the DIY guys like yourself (and save some $ in the process).
Go for it!!!