I've always wanted to do this. Being a programmer, I know I can handle the computer ascpect, but never had enough confidence when it comes to wiring and electric work in the car.

After I found so much helpful information on this forum and mp3car forum for this type of thing and reading through most of it, I think I'm ready to take the plunge.
Now I need all the help I can get from the veterans here to prevent me from screwing anthing up royally with my 8.

Here are the components I will be using...

old dell 500m laptop (have it laying around, why not, centrino so it should work well)
JDM retractable nav tray - got it from the japanese site so I think I'll have to clip one of the stubs to get it to fit the US dash.
xenarc 700 tsv
carnetix p1900
BU 353 USB GPS

I plan to work in pieces so I'm not worried about usb hub, backup camera, and the works just yet. Only reason I have the gps is because it came in a package.

I've already soldered the on off swith on the laptop to an extra earphone jack for removability. So I think at least one hurdle is out of the way.

Now I have some questions...

Power. I would prefer to get it from an add a circuit module that people on this forum have used, but I'm not sure how it works. I saw the fuse diagram from the car manual, and there are several "spare" sockets. Should the add a circuit go in one of these, or is it more like a splitter that plugs into one of the existing fuse slots and gives you an extra 12v connection that way?

And sound. I was perfectly content with the auxmod or the pie adapter, until reading up on the Car2PC adapter. It seems many people use Car2PC, some say it works awesome, but some have had problems with back button and noise (requiring a GLI). What's the latest on this? Is the back button still nonfunctional? Should I go with the car2pc at all?

Thanks in advanced!

 

I have a spare IBM T30 and I was thinking about doing the same thing.
As for power, I think you need to isolate the laptop from the car 12V power. It may have something to do with voltage spikes that need to be filtered out. Is that what the carnetix p1900 is for?

You may want to read this: https://www.rx8club.com/showpost.php...5&postcount=29

 

Thanks for the link, I actually saw that thread a while ago, but forgot about it. It looks like he's using it as a splitter... Does the add on come with a fuse or does it use the existing (e.g. 30amp) fuse? Anyone know if it means I need 2? one for each of the battery wires in the carnetix?

The p1900 is very similar to the p2140. They're both dc-dc regulators, providing stable voltage to the laptop and the monitor. Both have a lot of nifty features like stable voltage during crank, auto shutoff when battery is running low, startup shutdown controller, etc.

From what I've read, most people go straight to the battery, I'm hoping to avoid have wires running through engine bay if possible, simply because I don't know what each component does and how hot they get.

 

Hi lazyboyw,

This link may help you with the wiring https://www.rx8club.com/showpost.php...0&postcount=21. If I remember right the add-a-fuse will use the existing fuse.

In IsMao's post he using 2 add-a-fuse's one supplies power to the PC through the 2140 connected to one of the red cables on the input.

The second is connected to the yellow ignition cable on the 2140. The yellow cable powers the 2140 when the ignition is turned. Keep in mind both fuses you tap should be switched with the ignition.

 

Thanks for the info. I've been reading and re reading that thread since there's so much information in it. And also this one by maskedferret.

I've got most of the components (except the dash piece and car2pc adapter), been continuing my research and it looks like my laptop may have one of those proprietary plugs that wont charge the battery with the carnetix. If that's the case I'll need to pick up an auto adapter or inverter and use the p1900 for the startup shutdown, monitor, and hub (i have the p5v attachment).

Would that work? The p1900 doesn't have to have the primary output plugged into something, does it?

 

The reason I pointed you to the post is in regards to you choice of display. In that post the author said that the display suffered readability problems in strong sunlight.

 

I use the PIE adapter with an Alpine serial cable for my CarPC to play it's MP3's through the CD changer port in the factory head unit. Works great and never had any problems with it.

Where you are thinking of locating the PC itself?

 

Oh! thanks for pointing that out.

Unfortunately, I really didn't have a choice in the matter... The transflective displays he was talking about run about 300-500$ more than the 700tsv, there was no way I could afford to sink that much money on such a thing.

I've also had some bad experiences in the neighborhood I'm living in. Had my ol' miata broken into twice, once they broke the window even though the door wasn't locked (I gave up locking the door, hoping they wouldn't cut through the top). And granted the 8 has alarm, as the saying goes, if they really want it, they'll get it.

Finally I saw a really nice used package on the classifieds over at mp3car including the power supply, gps, monitor and some other little goodies for 350 (price of a new 700tsv + p1900 is already 450) so I had to jump at the chance.

I tested the monitor today and at least at night, it's stunning. So I may not be able to use it much during the day (maybe I'll set up a mic and a voice command system) but I could just take more night drives

 

I just tried stuffing it under the front seats today, doesn't seem to work. It either gets in the way of the back seat passengers or it has to go over the little bump under the seat. So I'm thinking the trunk. I'll run the power line along the driver side, and the rest of the cables through the center console if possible.

Where did you put yours?

 

My CarPC is under the passenger seat. But I have a custom mini case using Jetway components and a laptop 2.5" SATA hard drive. The case is roughly 10"x8"x4". It is pushed right up against the floor vent at that hump, and with the passenger seat installed, you can't see the case. You can only see it if you tilt the seatback forward and slide the seat all the way up, then you can just see the tail section of the PC case.

I love it in that location because it is completely stealth. Hidden from view, and all the cables are run through the factory location Mazda uses for the airbag harness, and then through the center console. It keeps it extremely clean with no visible wires.

I was worried at first with the PC under the passenger seat, if it would overheat, but so far no issues. It's run perfect in the hot Phoenix summers, and now in the winter with the floor heat even being blown directly into the case.

My Car PC was built by Boxcar Solutions, he is a good personal friend of mine. The thing is bullet proof and works perfectly, great prices, highly recommended (shameless plug over...LOL).

 

Your setup sounds awesome.

Size is definitely one of the cons to the laptop. Cant really fold it up, put it in an enclosure and stash it away somewhere. If i didn't have a laptop, i would've done exactly the same thing. Have you seen the imac mini in the rear elbow rest compartment? It looks like it was designed for it, the fit is nearly perfect. Kimota's setup looks pretty cool as well, you can go in and change anything any time, just open the glove compartment.

Does anyone know of any bags or hanging mounts with straps that I can put the laptop in and have it stick to the back of the seats? Then I can just cut a hole and pull the wires through the center console like you did. Hmm... The straps may even act as a shock absorber . And it wouldn't be that noticeable with the tiny flip out windows we have in the back. heh just a thought.

 

How are you going to turn the laptop on remotely? That would be an area of concern for me.

Location is a big deal, it can help or hurt with PC temperatures, and the overall look of your system. I started my first CarPC build with a used HP E-Vectra PC- it was 13"x13"x6", as big the average shoe box and weighed a lot.

It became rather difficult to find a place to stash it. It wouldn't fit under the seats, so I tried the trunk. I was originally going to build an aluminum box to hold it and bolt it up against the backs of the passenger seats in the trunk, but I decided it wasn't worth it and went with a dedicated custom CarPC instead. Much happier.

I wouldn't worry about viewing the screen- I have a cheapie E-Bay VGA TFT color touch screen monitor that works just fine, and I can view it in most lighting situations. If I can't see, I just use my hand as a visor to block the sun. No big deal. Plus, the monitor was only around $150 bucks, vs over $500-$700 for a Direct Sunlight viewable monitor? No thanks

I have some pics of my CarPC, I should start my own thread as well!

 

This is the only part I think I've figured out... I opened the panel covering the power button and soldered the two metal contacts to some really thin wires. Then where the wires exit the laptop, I connected them to a 2.5mm headphone female jack. And I have a male plug for this connected with two more wires. I intend to split these two wires, so that one set goes to the carnetix startup shutdown controller, and another goes to a momentary switch which I'll probably mount somewhere or hide in the arm rest compartment. I'll take some pictures later, that'll probably explain it better.

How did you secure it under the seat? I would think if it's just sitting there, it would slide around during turns?

I took another look at IsMao's post alnielsen linked to, he has a really interesting way to mount the computer. I wonder if I can do something similar. How hard is it to take out the passenger seat? Does the airbags and stuff get in the way? Since the laptop is so low, maybe I can put it on a sliding shelf under the seat (over the hump).

What are you waiting for! I'm sure many people will benefit from it, do it!

 

The PC is secured via 4 self tapping screws that go through the bottom of the case and into the floor boards. It was done by physically removing the top lid of the PC case and then marking the spots and then driving the screws in through the case. It also makes it kinda theft-proof (besides it's hidden and there is a seat on top of it....) because you have to disassemble the PC case to get to the screws.

I understand your power switch- seems cool.

The rear seats are no big deal to remove. The seat bottom just come out with some persuasive tugging if I remember correctly. The seat backs have two bolts in them I believe- I may have it switched around tho....it's been a while.

 

Well I went to a few auto/hardware stores, to get my hands on some of these mini add-a-circuit things. I found them in a few stores, but it's all the same brand, and on the back it says

"WARNING: This device is not designed for use with accessories requiring more than 10 amps!"

Here's a link to the item.

I tried to find something that could take more but this is all they had.

With the label warning, my first concern is can I still plug it into a slot currently holding a 30amp fuse?

The other thing is, the p1900 is rated at 140 watts, and the p5v is 15 watts, so I'm thinking the fuse would need to be 13 amps or so on the 12v line.

Would I be safe if I use two of these add-a-circuits for power? Then each add-a-circuit should have 6.5 amps going through them, right?

 

Let us know when you have your xenarc 700TSV mounted. I'd like to get your feedback on readibility. Also, did you consider the Lilliput 629GL-70NP which was cheaper, or the reasons you didn't?

 

Will do, still waiting on the dash piece. I have everything else ready to go.

Before I bought anything, I researched the lilli 629, 619, xenarc 705 and xenarc 700.

From what I've read, there isn't much gap between them, all will perform well at night, and none will be viewable in direct sunlight. The only screens that are day time readable are the transflective ones.

The history and stats all seem to favor xenarc a bit. Lilliput had a reputation of using refurbished parts and selling as new, although I think they stopped doing that. Also the brightness and contrast seems to favor xenarc a bit as well (liliput use to have 200:1 before the new version), but many people say the difference is negligible (I think lillis now have much higher contrast) . Lillis always have a great price tag, and if you look around bit, you can usually find it even cheaper than on some of the bigger named sites.

I think the last difference is voltage regulation, the lilliputs aren't regulated, where the xenarcs are. I had an incident a few days ago when I first got the screen. I tried to plug into the wall and it didn't work, I later found out they shipped the wrong ac adapter and it is only supply 5 volts. So, I was thankful I picked up the xenarc. I don't know how lilli's would have handled it, but I'd be worried.

In the car, if you have a regulator like the carnetix or some other power supply, then it doesn't matter either way. If not, and you don't plan on buying one, you'd probably want to go with the xenarc as well.

I actually wasn't looking to buy a 700, as it was the "higher end" model for xenarc, and I didn't really feel the need. I thought the 705 would've done fine, so would the lillis. I just happen to stumble upon a package that had pretty much everything I was looking for. So I jumped at the opportunity.

 

Thanks for the explanation. I came down to the same conclusion that the two brands aren't that much different. However, I seem to find more people have issues with the Lilli. At least from being on mp3cars.com. I actually read your post regarding that issue you had with your Xenarc.

I will be running the carnetix P2140, so power regulation shouldn't be an issue. I'm retrofitting the screen into the stock nav hood, and the guys here all went with the Lilli. All are about the same size with buttons along the bottom, however the Xenarc 705 is said to be, "ideal for mounting and custom molding due to the sharp corners and flat edges." I still have a bit more to read before making the jump.

 

Cool, good luck with your install! Keep us updated!

I got the notice on the door today saying the dash piece is waiting for me at the PO. Looks like I can finally start tearing things apart.

Anyone have any suggestions regarding the mini add-a-circuit thing?