Dodge Caliber Forum banner

Adding Door Keypad

42K views 60 replies 20 participants last post by  neonpolaris 
#1 ·
As a pet project I was thinking about adding a door keypad. I had one on one of my previous cars and I really enjoyed the convenience.

I'm thinking about repurposing a Ford keypad (as a weather-proof set of buttons) and interfacing with a microcontroller, like an Arduino. I almost have the source code finished. Interfacing with the locks shouldn't be any harder than an aftermarket keyless entry install, which I have done before. Cutting a hole in my door is extremely scary, but would look the best when finished. I'd just get a keypad with a bezel around it so that it will look clean when I'm done.

So a few questions. Has anyone done something like this before? Any lessons learned?

I noticed Ford actually had a keypad that just stuck on the outside of the door. It programmed just like a second keyless entry remote, so there was no wiring needed. Is there anything like this for Dodge, maybe aftermarket?
 
#8 ·
but if you need to get somthing from your car and you dont have the keys with you like you r at a famly get to gether and you need somthing put you better half has the keys

and you still have a working key fob all the systum does is tie in to the door lock solenoid

and isent hte point of moding your car to stand out from the other well can u think of a caliber that has a key pad i thing its amazing ans i really want to see pic whwen its all done
 
#10 ·
since owning my caliber, i have locked my keys in the car twice.

both times I got mucho lucky... first time about 200 miles from home but a chrysler dealership was just down the street. I got them to cut me a key off the VIN.

second time not as far away, but still equally a hassle... locked them inside, on a military base after hours, and my fiance had a key back at her house...

i got lucky both times. a keyless code like that would be awesome for me.
 
#14 ·
Research

Ok guys, I can see two different ways of accomplishing this task. I can either have my module interface with the door controls, like most aftermarket keyless entry kits do, or I can interface it with a keyless entry remote.

Wiring it to a keyless entry remote stashed inside the door seems kind of hackish, but it would allow me to be able to unlock just the driver's door and optionally the other doors, which I cannot do from the door controls. Also, there's alot less wires to splice into this way. I would want to power it off the car so I wouldn't have to pull my door apart when the battery would go dead. I think I could buy any dodge key for the caliber and program it in, since I don't really need the key part.

I don't really know where to find out which wires available inside the door I could use for power. I think there's actually a 5v power available for the door module. (this would be better for my microcontroller than 12v) I wonder if it would mind if I used a little of that.
 
#16 ·
Not 'everything' communicates via canbus data. As per the12volt.com, regular aftermarket keyless entry modules are compatible.

It says Lt. Green/Dk. Green wire to (ground?) with 250 Ohm resistor is Power Unlock, and the same wire with 1000 Ohm resister is Power Unlock.

I'm heavily leaning towards throwing a keyfob in the door, though. I just have to feed it the 1.5 volts? that the battery would.
 
#17 ·
Progress

Ok, so I have my device mostly programmed. I soldered together a test keypad today with 5 buttons. I have the arduino programmed to listen to the key presses and light a green led when the combination is right. You can pad the combination with as many presses as you want, as the array gets shifted for each press.

Also, I've programmed a timeout, so the array gets reset after 4 seconds.

I still have to implement the extra unlock with another keypress, and the lock via last two keys.

Does this forum let you post YouTube video? I'll probably take a quick demo vid soon.
 
#18 ·
Little More

Ok, I popped open my key and the battery is 3v. My multimeter read 3.30v from it. This is awesome because the arduino board actually has a 3.3v out that I can use.

Does anyone know where I can find which wires in the door supply power, and at what voltages?
 
#21 ·
8W-80 gives me pinouts, is "B(+)" supposed to be battery? I don't know about all of this, I don't want to try and tap into something and fry some obscure electronic module. Maybe I'll just put a nice 5v regulator somewhere and run a new wire to the door.

---

Also, if this chip draws 20mA @ 5v, (0.1W) would it be fine to have it running all the time? How long until it would drain the battery?
 
#22 ·
Progress

Ok, so I whipped up a quick and dirty keypad for testing.



So I can preset the code in software, and when I enter the right combo the green LED lights. This will later activate the keyfob instead.

What I haven't done yet is implement the extra button to unlock ALL the doors (hit the unlock a second time, within 5 seconds) or lock by pressing the last two together at any time. But it is progress. I've never dealt with programming in C, so I'm taking baby steps. Once I get the software done, I'll work on more attractive (smaller!) hardware.
 
#23 ·
Software Done

Well, I finished the software tonight. It takes the combination and unlocks, will do an extra unlock if the correct code is followed by a '3' within 4 seconds, and will lock when the last two are pressed together at any time. Oh, and I fixed the debounce so it actually works now. :)

By 'lock' and 'unlock' I mean 'light green LED' or 'light red LED'.

So what I have left to do is:
Interface with the keyfob (not here yet)
Wire to keypad (not ordered yet)
Replace Diecimila with Nano (smaller Arduino board, not ordered yet)
Install!

So it seems like I'll take a little step each time some hardware gets in, and then wait. But I don't want to proceed until the prior step works. Alas... waiting.
 
#25 ·
placement

So today I actually *looked* at my door. There isn't really enough room for me to put a keypad above my door handle. The door isn't flat enough there to stick a keypad.

Below the keypad seems to awkward to use, so I guess I'd have to put it to the left of the handle? Not really where I'd like it, but I don't really see any other options.
 
#26 · (Edited)
Hey guys, I'm making progress, but I'm still waiting on parts. I've taken my door open (removed door bolster) and have done some investigating. I have the service manual for the 2007, but I have a 2008. One would think that they'd be practically the same, but I've found some large differences between this manual and my car.

The manual says that to lock the doors, the resistance value between pins 2 and 3 should be 1K Ohm. To unlock, on the same pins, the value should be 249 Ohm. This is not the case on mine. I took apart my button assembly and actually looked at the board. The lock/unlock buttons switch a 100 Ohm and a 330 Ohm resistor for lock and unlock. (I forget for sure which was which)



Also, they were mapped to different pins (not 2 and 3). They are the Lt. green/Dk. Green and the Black/Yellow. I was able to confirm this by actually making my door lock and unlock with a 100 ohm and 270 ohm (closest I had on hand) resistor between those two pins. I noted that this worked with the controls both plugged in and unplugged. These values would be important to someone installing an aftermarket keyless entry/security system.

I also have step by step pictures of the disassembly of the entire door controls and a good picture of the best way I found of taking the window switches off. Perhaps I'll post them if there's interest.

--

Also, I think that this thread might have been better placed in the internal/electrical mods now, instead of the external/body kits. I mean, it was about a keypad, which is external. But it's more about wiring now.
 
#27 ·
I got my keypad in earlier this week, it's from a Ford Explorer. The pinout on it is perfect! It operates essentially the same as my test keypad, so I don't even have to change my source code for it. It also has a backlight that I didn't anticipate. It only took 3 lines of code to support that (lights up on keypress, then out after specified time).

Now, something that may be more interesting for the rest of you, I tested the door wires for voltages yesterday:

Lt. Green/Dk. Green - 5v always on, but don't use, it's for sensing the door lock/unlock.
Pink/Gray - 12v, on-off with ignition
Red/Dk. Green - 12v always on

Black/*anything* = Ground

These are from the three plugs going to the door controls (and mirror controls) on the driver's door of a 2008 Caliber.

So, it seems that I don't have to run a new 12v wire to the door. I was sure that all the 12v's to the door were off with the key. Now, the always on 12v is a smaller gauge wire than the one that is on with the key. So I wouldn't try to use it to power a window motor, but it runs my microcontroller just fine and it should handle that backlight (led) also.

So, I've got my other electrical components ordered, all I have left to find is some good *sealed* connectors to use, so it can be more easily removed if I ever wanted to make adjustments.
 
#29 ·
Still Alive

Hey everyone, I just wanted to let you all know that this project is still very much alive, and has evolved somewhat. (hence the delays)

Here is the keypad that I originally intended to use:


It's from a 90-something Explorer. Here's the scratch-sheet schematic:



And the board I created for it:



The bottom is not elegant:



The board tested perfectly, I even ran it on 12v (in my house) for a week, and it was rock solid. But I decided that I wanted a different keypad. You see, the one pictured above has a solid membrane across the front. The first few buttons had a nice tactile response to being pressed, that is, you could 'feel it' when you pressed the button. But the last two, although they did work, didn't feel like you were doing anything. Since I'm ridiculously picky (and worried about longevity) I found another keypad. I found this one on a 2008 Escape: (Although it's on heaps of other models/years)



It has a nice feel, is good enough for Ford to use on their vehicles now, and still has the backlight. Unfortunately, it is not wired the same internally, so my old board is useless. I rewrote my program to handle the new keypad properly, but I still needed a new board. Instead of making another monstrocity like that first board, I learned enough Eagle to design a PCB and I've already sent it off to be profesionally fabbed. So now I'm waiting on this to come in the mail (a few weeks):



Note: That 1K resistor on the right side, above the 330, is incorrectly labelled. It should be 100. This board should fit just perfect into a radioshack 1x2x3in project box, and already have holes drilled to line up with the internal mounts in it.

I have the weather-proof connectors coming, all my headers, resistors, connectors, and optical relays also. This board is more modular than the other one with quick disconnects for all external connections, and I'll be able to easily remove the Arduino Nano (the brain) for reprogramming. I think I'll stick it in the door with some servo tape, and see how it holds up.

I'll post more when I get the pieces in!
 
#30 ·
Board is in!

My board came in today and it looks good! I can't wait to get home and try it out. I ordered two, just in case I royally mess the first one up on assembly. :) I really would hate to have to wait a whole extra month. I'll post more pics when I get it all put together.



 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top