My In-Dash Car PC project

[TheForce]

I got my parts in today for the switch.

I'm finished with the bread board layout and everything works like it should. I should note that since the VGA adapter boards only use 6 pins I will be using two 4PDT relays and one DPDT relay to save a little space.

VGA adapter boards were bought at http://www.knjn.com/ShopAdapterBoards.html

All other parts were bought at http://www.digikey.com or http://www.jameco.com

The VGA adapter boards allow the DB15-HD to fit the normal bread board or project board hole spacing. I went this route because soldering wires directly to the project board for VGA would be a PITA. Plus you would have 3 big wires coming out of the box for the VGA signal. I wanted a more compact design that you could plug your cables into it and buying these adapter boards was the only easy way to do that. Other wise I would have to etch my own board and drill holes. I just don't want to do that right now.

Every thing works like it should but tomorrow I will be installing the USB and VGA parts to the bread board. I will then give it a trial run with two computers, monitor and USB mouse. The two computer will simulate the can-view and the car PC. The monitor will simulate the indash screen, and the USB mouse will simulate the USB touch interface. I don't see why this wont work since the relays are switching but you never know.

Here is a pic of the current breadboard fully functional. I put LEDs on the relays to see if they were actually switching and they will be removed for the final design.

[TheForce]

I've now tested everything out. The USB switches just like it should as well as the VGA signal. The VGA signal was a little dirty but I expect that to be cleaned up a little when I get everything on a project board.

I made a small design change. The transistors were getting very hot with the 2.2k resister. I replaced it with a 39K resistor and they seem to keep very cool while still switching on the relays.

Now I got to work on a project board design.

[edit] I should note the VGA adapters had very very small tiny eitty bitty resistors on the RGBHV lines. I removed them to make sure I got a nice clean signal. I think these adapter boards were meant for some kind of other project that requires resistors.

[priussoris]

Very cool, You got yourself the new version of the "Batmobile"

[Cheap!]

I am looking forward to your testing the project board. Great job.

[TheForce]

I decided to separate the power/switching circuit and the relay/connector board into two different project boards. I did it this way because I did not think I could cram all the stuff onto one board. I probably could have but it would have taken me weeks to organize the traces to a small compact form. So I just decided to take the easy way out and put them on two separate boards linked with a 5 pin wire harness. 4 wires are actually used. I figure doing it this way may also help keep out any interference that might screw up the USB and VGA signals.

I also updated my schematic above to reflect the new changes.

Here is board number one finished, tested, and working like it should. This board includes the power supply and the switching circuit.

[TheForce]

Board number two built and bench tested. Tomorrow I will give it a trial run in the Prius.

If everything works like it should I will be putting them in their project boxes.

[edit] I added a pic of the back of the of the connector board just so you know what it looks like. I'm not adding one for the power supply/switching circuit because its basically just like my other video switcher for my anytime front/rear camera. If you want to see what that circuit looks like you can just look up my topic on the anytime front and rear camera because its basically the same thing..

[TheForce]

Just finished testing it out in my car. It works just like it should!

I seen no interference in the video signal. That does not mean there wont be on when I finish the install. I still have to run a VGA cable from the rear of the car to the front. The longer the cable the more signal loss you will have. I'm confident that the low bandwidth resolution 800x480 signal will hold strong on the finished installation.

Now I'm looking into buying the actual PC. I still dont know how I'm going to turn the thing on. I dont relly know what kind of button(s) to buy and where to install them yet. I still have plenty of time to figure that out though. Only about 50 days left until Hybridfest. I doubt I will get it finished by then but I'm still trying my best.

[Presto]

For turning on the computer, most 12V PSUs will have shutdown/startup controller that will automatically turn on the computer when the car turns on and begin a shutdown process when the car is turned off. There are some adjustable time delays for both shutdown and startup sequences.

[TheForce]

Thanks for that info Presto. I still think I want to choose when the PC boots so I will still need to find a button and a place to put it. I'm currently thinking somewhere under or beside the screen.

I now have the switch all finished and in the project box. The two boxes are held together with velcro with a sticky back. The linking cable has a quick disconnect for easily disconnecting the switch in case it needs repaired.

This is the VGA side and you can see the power cables on the right hanging out.


This is the USB side. The USB ports are recessed back into the case. You can see the linking cable on the left. This cable only provides power to the relays.

[Cheap!]

LOL

Nice work Force!