Several months ago I begun a project to create a control board to manage the functions of the navigation housing. There have been a few similar projects on this board. I undertook this project wanting to make a product that was as seamless as possible with the OEM parts. I must say that if I had known then what I know now, I probably wouldn't have even started the project LOL. It has been a real pain in the butt, however the end result is something I am very proud of and it functions exactly the way its supposed to. Special thanks to Chainu for his groundwork.

As you can see from the pictures below the board itself replaces the small rectangular OEM board which is mounted on the outside of the navigation housing. You'll notice the 4 jumper housings at the bottom of the board.

Jumper 1 (far left) is a 5 pin molex microblade housing. It is connected to the factory wire harness. It provides both constant and switched power, two leads for the illumination of the tilt and open buttons, and finally a ground lead.

Jumper 2 ( 2nd from left ) is a 6 pin molex microblade housing which mates with the OEM molex connector of the tilt and open buttons.

Jumper 3 ( 3rd from left ) is a 3 pin molex picoblade housing which mates with the trimpot aka potentiometer attached to the motor which opens and closes the housing.

Jumper 4 ( far right ) is a 2 pin molex picoblade housing which mates with the 2 wire plug of the motor itself.

Essentially there is no need to cut, solder or otherwise mess with the internal wiring of the car to make this work.

Because I spent so much time working on this I failed to take pictures of the actual assembly process even though it literally only takes 5 minutes if you don't count the time to remove the radio from the dash. Its all pretty much plug and play. I intend on taking some more pictures with the housing pretty much assembled, and some video of the board in action.

The board allows the housing to open to its last position when the key is turned to ACC or the car is started. It will then close automatically when the car is turned off. It has 3 tilt positions and the open button opens and closes the housing. The buttons retain their illumination and will dim if you dim the main console lights.

Anyway here are the pictures of the board itself. As this was a prototype I didn't specify a soldermask when I had them manufactured since it costs extra and I'm fairly proficient with the soldering iron. So you'll notice the yellow substrate and of course the copper traces are bare.

Side by side comparison of the original pcb and mine


My pcb by itself.


PCB attached to bottom of OEM tray


Completely assembled ready to mount to nav housing


Backside of completed assembly


More to come

 

wow, just amazing. Plans on selling this?

 

I didn't have any immediate plans for selling it, although I certainly wouldn't mind that. I would have to gauge the interest in the nav board before I could make a determination.

 

Wow...very clean and nice....I would certainly have paid for this. I ended up creating my own cheap and quick solution using an Arduino PIC, but is not even close to this. Congrats

 

Beautiful! I think there would be a lot of interests if you decide to sell this solution. More and more people are able to source the OEM nav units now more than before and would benefit from this. I'd sign up.

 

Hey guys, I was going to go out and shoot a short video which shows the functions of the control board today, about 30 minutes ago, only to find out the rechargeable batteries in my camera were pretty much dead. So I guess I'll have to wait until tomorrow to do that. I don't own a camcorder so at this point I'll have to do the video with my digital camera which is only 640 pixels aka it won't be great quality but it should be good enough to show what this board can accomplish.

 

Looks familiar, lol. This is amazing! Great work! I see now the white connectors for the plug and play for the buttons/motor/potentiometer are micro and picoblade. That's one thing I would have loved to keep simple instead of cutting and soldering, etc- but couldn't find the right connectors.. There were no complications with the motor and trimpot connector lengths? I seem to remember those being rather short. I like how the ICSP row pins stick out of a factory-cut location, just be sure they can't touch the metal lip of the bottom plate. Also, it's ingenious to make the whole PCB the exact size of the factory so it mounts flush, I don't know how much cutting by hand was involved, but that's awesome. I opted for the cheapest route and it just so happens to be a good size to fit behind the housing, but I'd certainly buy this when I decide to replace my scratched up factory housing, haha

 

Can't wait!

 

how much did it cost to make and are you going to sell them

 

I put a lot of consideration into the way I wanted it to look.

Just a little information for those that may want to know. The connectors as I mentioned are Molex brand connectors. The two smaller ones are from the picoblade series which have a pitch (space between the pins) of 1.25mm. The larger connectors are microblade series which have a 2.0mm pitch. The REALLY annoying thing about these connectors is they are ONLY made by the Molex company. Being a proprietary product that they are, it allows the Molex company to do as they see fit with them. These connectors, particularly these two series are actually fairly common in small electronics, however because of their applications you as a consumer typically won't see them.

Believe it or not the Lilliput touchscreens actually use a couple different microblade connectors in its inner housings, and like I just mentioned a typical consumer doesn't open up the casings of these touchscreens so you wouldn't see them. In any case, although they are fairly popular in terms of electronics usage, Molex designed them for mass production and automated assembly. The reason this becomes annoying is that because all of these connectors are proprietary and meant for automated assembly, in order to use them in small volume applications you have to either purchase a crimper made only by Molex or you can have the crimping job outsourced. The crimpers for these bad boys run between $200-$400 and they typically ONLY crimp 1 or 2 types of connectors.

Now as far as the cable lengths are concerned Chain, I think I mentioned in my first post that because I wanted this to be a drop in replacement I put these connectors in so that it would not require any cutting or soldering into the factory wires. So in order to do that a jumper/extension cable is utilized to extend the length of the factory motor and trimpot cables. Now because I didn't want to spend $200 on a crimper for 1 set of extension cables I was able to, through a lot of patience, crimp the connectors with a pair of small needle nose pliers. They work fine this way but its certainly not something I would want to send to someone if I were selling these boards. I have contacted a few cable harness houses who are capable of making these harnesses, but as you can imagine they require a pretty large volume of cables to be made in order for it to be cost effective for them. If I get to the point where I can do this, I can get these cables made for around $1 or 2 and it would be well worth it.

As far as the ICSP header is concerned, it doesn't really even need to be on the board if this were a production product. Most people don't have a pic programmer sitting around the house, much less know how to use it lol. I included it in this project much as you did because it makes it a lot easier during testing and tweaking. It actually sits over the board by a couple of millimeters.

This didn't require any cutting myself because when I designed the board outline in my pcb layout software I used a digital caliper to measure the exact dimensions of the factory board. When the boards were manufactured the routing machine did all the cutting including the slots.

I myself have a degree in computer science and I recall taking a course in beginning digital circuits but I really didn't remember most of it. When I started this project I basically had to teach myself everything about it. I started out by learning schematic capture, then taught myself about Pic controllers and how to program them, moved on to pcb layout and manufacturing, and on and on. I can pretty much teach myself anything when it comes to electronics. Another annoying trait I have is I tend to never be satisfied when I am doing something like this. I get done doing the things I set out to do, and then I start thinking about other things I would like to do. For example this board in its current form does not control the on/off functions of the LCD screen. In other words if you close the LCD housing it won't shut off the LCD screen. Since my LCD screen is run from my M2-ATX power supply in my Carputer I didn't think it was really important to have that on this board. When I turn the car off the PC turns the screen off. If I wanted to include that function on this board it would have actually been really simple. All I would have had to do is include both and input and output barrel connector jacks, then have a pcb mount solid state relay controlled by the PIC.

Anyway just a bunch of useless information for those that are interested.

 

As promised here is the video of the control board in action. It was very sunny out when I filmed this so you can see reflections off the screen but thats not really important.

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You did a nice job on this. Is that a factory screen or did you put a different screen in the factory housing?

 

It is a Lilliput 7" touchscreen. Oddly enough putting that touchscreen in the OEM housing was the most annoying and painstaking process of this whole project. There have been several people on this board and elsewhere is said that the Lilliput screen fits almost perfectly, I guess I have a somewhat different opinion about that.

 

Ay it was a breeze getting the screen in there.

 

heh, i could do with one of these!!

All my PCBs are in a big box, mounted under the dash. This would be perfect.