2006 Nissan Teana carpc intergration with factory screen
I have been a keen follower of mp3car for a number of years but never taken the plunge. While I was keen to have a PC in my car, I had issues about where a screen could go. That was my Nissan Cefiro – a Japanese import into New Zealand. The Cefiro (and most others for that matter) imports are not your stock standard international equivalents. They have quirks and things in them that you would only find in the Japan market. We import these used cars here as they are well priced and (typically) higher spec’d than the NZ new equivalent models. The more up market models have navigation and flash audio systems. The problem is most of the controls and feedback is in Japanese. Even the FM radio uses a different band (70 – 90 MHz) and the only way around this apart from ripping it all out and starting over is the use of a “band expander” connected in line with the antenna which “adds” 10 MHz to the received frequency. IE 89.4 on the display = 99.4 in real life. Adequate but not the best in a busy area
By now most of you will be saying “surely you can swap out parts, move jumpers, change menu options etc” but no, these are intended for the Japan market not the international market and they cant be reprogrammed. Many have asked and tried.
I now have a newer (2006) Nissan Teana. Both the Cefiro and the Teana are Maximas in the US, Australia etc. so share a few things. This 1 has a colour screen (non touch) which displays all manner of info – mostly in Japanese. By systematically working through I have managed to find things that control the auto headlights, the wiper delays, the interior lighting, the Bluetooth as well as a few others. Regardless of what is on screen at the time, volume, channel, climate controls etc. overlay on the screen. It has a reverse camera which takes overall priority when used. To me, maintaining this functionality is the most important part of my PC install. I don’t want another screen, but I do want a good PC experience – preferably touch.
I was inspired by a local person who had a box that ran Win Ce and iGo which could be added to your system by “interrupting” the RGBS feed to the display controller. I also found boxes that would allow you to interrupt the feed from the controller to the screen it’s self but these relied on switches or relays to change between modes. When in the PC mode, none of the overlay stuff could work so this was not an option for me. BTW the screen is an RGBS screen running at 15K so can’t connect VGA directly to it.
So, what I needed was;
• No change to current screen functionality (apart from not needing existing Nav)
• A pc running Windows using a touch screen
• Activation of the PC by pressing any of the exiting nav controls
• Seamless integration with all existing overlays working
• My target was less than $1,000 NZ dollars
August 4, 2012 - Work begins
I made a break out cable to connect to the existing nav unit to try to find the RGBS wires. Attachment 67453
Attachment 67451The connectors used were not common (a 32 way) but I managed to source them through RS components and they were quite cheap too. Having not been able to find the correct version of the shop manual for my car, this was a bit trial and error, however looking at the existing cables I found a set of 4 that were screened and guessed that they might be them and sure enough they were. By cutting each wire in my break out cable in turn I could see when I lost the red or the blue or the sync. I actually only cut 2 that were not relevant!
To confirm I was on the right track I connected my 17” LCD to the (now cut) feeds from the factory nav and my screen politely said “signal out of range, 15.7kHz / 60Hz”. Yey! I’m on the right track!Attachment 67454
So now all I need is a PC that will output this type of RGBS at 15.7kHz video right? I dug out my old test box PC and installed “Powerstrip”. I was surprised to find that this old dunga could in fact output these resolutions when using this program. It also had a tick box for “composite sync” and interlacing. The hardest thing about doing this kind of tweaking is that you often loose the display and can’t find your way back. By using VNC when ever this happened I could access the box over my network.
August 11, 2012
Using an old VGA to 5 wire tail set, today I connected my old PC to my break out loom. I booted up the PC and (as expected) the first few screens were all garbled but by the time it got to the desktop, low and behold it was (sort of) on the car screen! The image filled the screen but was split in the middle – clearly a sync issue. Attachment 67455 I played with the 2 sync cables I had and in the end actually joined the V and H sync from the PC together and this seemed to make the image correct. I can’t imagine how this could be but there you go. By playing with different resolutions, zooms and positions within Powerstrip, I got what I think is a pretty good image. The desktop was readable and quite crisp. Attachment 67456Attachment 67457
If I changed the volume or the temperature, the overlays came up correctly. Attachment 67458Attachment 67459 This was “proof of concept” for me and a reason to precede at full speed.
While Powerstrip did the business, I wasn’t convinced it was the best way to do it as it had to load after Windows was started at which point it would take over the hardware and output my resolution. Interestingly, when the wrong rates were being sent to the screen, the other screen info was garbled even though the PC was not being displayed at the time. To me this meant that all the different parts that connect to the cars display controller share a common sync “bus”. When I connected something weird to it it seemed to garble the whole lot.
So I decided to find a hardware solution to do the conversion for me. I found this quite hard to find but stumbled across a company in Australia that made products for the arcade game market. The old spacies machines had big CRT screens that all ran these resolutions and these guys were selling converter cards to convert VGA to CGA outside of the computer. I ordered the card and in the meantime decided on the Asus E45M1-I DELUXE motherboard for my project. This integrated mini ITX board had a PCIe slot, built in wifi, Bluetooth, no fans etc. Attachment 67460
I found a space in the boot (trunk) for it to go and waited for the card to arrive before making a call on a case.I’ve ordered 1 and we will see how it goes.
August 18, 2012
Spent time working on the case over the weekend. I made the case from Perspex and ended up with a fair result. Attachment 67460 It was my first time working with this stuff so was a bit hit and miss. Attachment 67462 I am going to use a laptop hard drive and wanted to shock mount it in the lid of the case. I used some O rings and stand offs to do this. They allow about 5mm of movement in all directions. Attachment 67463 Later I may change to a SSD but they are still a little pricey for this project. Building it with Perspex cost about $25.00. Attachment 67464 The case I wanted (and may still get later on) is something like a Voom but these cost more than 5 times that once you land them in my part of the world. I am going to need a case fan but will do that before it goes into the car. Attachment 67461
The VGA to CGA board arrived during the week and I tried it on Saturday. I’m not completely happy with the image quality (a bit soft) but I’ll live with it for now. I was running XP and my intention is to run Win8 which has big icons intended for mobile (touch) and small hardware as seen on tablets. I haven’t tried this yet so will be happy with the image for now.
I had previously run the VGA, power and usb from the boot to the glove box so properly joined this into the break out loom I had previously made. I mounted the PC properly with the ability to easily remove it from it’s home if needed. (I imagine this will be needed quite a lot at the start) Have ordered an M4-ATX from eBay and expect that in the next few days. I’ll build another small Perspex box to house this and the VGA to CGA close by the computer. I’m going to be close to a supplier of touch screen overlays next week so will go for a look at that.
Was out of town last weekend but purchased a touch screen overlay while away
The size was such (7") that it fitted perfectly inside the metal frame of the LCDAttachment 67465
And the thickness was also perfect bringing the surface to exactly level with the side of the metal frameAttachment 67466
I mounted the touch to USB controller on the back of the screen along with the ribbon cable from the overlayAttachment 67467
The M4-ATX arrived during the week and it's been mounted in a small case in the boot beside the PC. (Pic coming soon)