Scratch Build – In Progress RX8-CarPooter - July 27th 2009 - Software: WIP. Hardware: Nearly done.

looking good...

 

I'd suggest you read up on just how the power distribution system works in a car before you go any further with this project. Your inability to understand how fuses work is scary enough let alone reading about how you intend to power the unit from ignition.

Please, for the love of your car, do your research first!

I'm more than happy to tell you in detail just how to go about the integration process, just not this second as I'm about to head off to a kids party

And yes, I know what I'm doing with cars and computers as I used to build emergency services vehicles.

 

Well, by all means, if you have the time, you're welcome to share your knowledge

However I'm just following the instructions from the PSU's manual (manual is stretching it a bit.. it's exactly 1 page long ).

I think I may have grounded it wrong though.. Getting an awesome engine noise coming through the speakers, it amplifies the sound of the engine and makes it high pitch.. that and I can't pick up any FM/AM radio waves >.>

 

Honestly, not my cup of tea..
BUT, never the less.. Congrats on MOTM..

 

from my experiance usualy all grounds are common, meaning no matter which one you use the ignition will not affect it. so your best bet would be to find a nice bolt/nut going to the chassis, make sure theres no paint and get a nice heavy (8 or 10 gauge maybe a 4 or 6 gauge) ground wire attach it to the bolt/nut then attach it to your power supply. then set up a fuse on the positive wire and attach it to your ignition switch. kinda like how an amp for speakers/subs has the signal wire so it only turns on when your stereo is on. i believe there was a forum posted somewhere in this thread where all they do is carputers, they would be able to explain this alot better than i can.

 

Doesn't the car psu have a trigger wire, just like car amps? This trigger wire wouldn't use much current at all, so you can hook it up to any acc supply, even the cigarette lighter for example. The power supply wire however, should be an appropriately thick lead direct to the battery, with a fuse as close to the battery as possible.
A nice thick and short as possible earth lead to the chassis is good too, preferably 10cm or less.

That engine noise you are getting is probably ignition noise/ground loop, and if so can be eliminated by:

Nice thick & short earth lead to the chassis with a nice low resistance connection, such as 4ga cable, a large soldered eye connector, bolted to bare metal. This may be a pita to do on a car you don't want to modify, but look around and you will find an out of sight place to do it.

Make sure all car powered pc devices use this same earth lead! Video cameras, microphones, hdd's, pc psu, mobo tray, etc, every earth! Otherwise they too will have to use a short & massive earth lead to the car chassis.

The ignition suppressor cap may be dead, but i doubt it since the car is new.

 

Oh snap I didn't even notice! Awesome! Thanks!!

Both of you are correct, the PSU already has a 15A fuse on it, it's built to turn on/off with the Ignition position. The way it works is, when you turn the key from ON to ACC/Lock, the PSu sends a shutdown command to the mobo and gives it 30 seconds to shut off before it cuts power and goes into standby mode, at which point it'll go into fully Off mode after 2 hours.

I have a grounding wire running 8 or 10 gauge, I forget right now, going straight to the chassis where other wires are grounded, I'll get pictures in a bit. I do need to shorten it, but everything is more or less placeholder until I get the enclosure in place, I've been looking for another ground area, haven't found one yet though.

Both the wire going directly to the battery and the wire going to the cig lighter are also the same gauge wire.


Gonna grab you guys some pics to better explain it.


I've also taken dimensions to enclose the computer, the cardboard was/is only temporary as I needed to make sure it would work and mainly to test how it does with shocks/bumps.

Unfortunately due to the VERY rough suspension in the RX8 (but oh so wonderful to drive hehe) whenever I hit a slight bump in the road at over 30mph, it locks up the computer. To Combat this I'm going to try to see if I can create a spring-loaded motherboard tray with some very loose springs to try and soften any bumps.

 

Ok here we go, the hi-res links are even higher res than before! (hurrah D60), however, I couldn't get the images down to 800x600 because the current computer I'm using only has Paint and it's complete crap for resizing.. so instead they're 872x564 or something odd like that.

Shot of the PSU.. I realized as I was typing this that the pic doesn't show the fuse.. Oh well. The black goes to ground, red goes directly to battery, and white goes to the cigarette lighter:


Hi-res: http://tech-burrow.com/bittech/DSC_0031.JPG

And here's a shot of the ground wire (one that comes in from the right bottom corner), it's maybe like.. 2 feet long barely:

Hi-res: http://tech-burrow.com/bittech/DSC_0032.JPG

Ninja-edit:

Sorry, early morning, the PSU pic does include the 15A fuse

 

off topic, but Nikon cheesecake (H)

upload via tinypic or photobucket, then you can resize to 800x600 as you're uploading

 

Well, I prefer keeping everything on my server, makes it easier for me and it ensures that the pics won't disappear due to bandwidth, etc.


I've got more pics of the inside detailing the frame.

Right side:

You can see the XM radio receiver. I originally wanted to do something like that, and put the computer into the side of the trunk, which would make it where it doesn't take up ANY space of my trunk what-so-ever, but my main problem would be that the computer would freeze if I take a bump, and do to a spring-mounted motherboard tray I need it to be hanging straight down.

As you can see, the right side has PLENTY of holes in the frame:

Hi-res: http://tech-burrow.com/bittech/DSC_0033.JPG

The left side however doesn't really have as many places to ground:

Hi-res: http://tech-burrow.com/bittech/DSC_0034.JPG


Ninja-edit:

Oh yes, the case I'll be sticking all of this into is this one:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811190108



It's really tiny at 2.8” x 7.3” x 9.8” (HxWxD) which should make it perfect for fitting it at the top of the trunk securely without really encumbering trunk space. Some modifications will of course have to be made to the case.

 

You wanna make me one next? =)

 

Get the parts and I'll help you

 

So today I figured out what was wrong with the buzzing sound I was hearing and possible interference with the radio. You can't have power cables (from the battery anyways) near audio cables. So I'll be re-routing the main power cables through the door frame floor.

Also, it appears my SSD mysteriously died, still investigating that..

 

That's a shame, those things aren't cheap.

 

ya unless both cables are shielded you dont ever want to run power next to anything else due to well the issues your having.

Bummer about the SSD, keep us updated on that.

 

Alright I have good news!

For starters, the case arrived today, and I was immensely surprised when I saw it had an ODD to IDE PCB board add-on, which fit perfectly to a DVD drive I had salvaged off my Dad's dead laptop, so now not only do I have a nicely sized case, but a DVD drive too!

Anyways, pics:


Hi-res: http://www.tech-burrow.com/bittech/DSC_0045.jpg



Hi-res: http://www.tech-burrow.com/bittech/DSC_0046.jpg


Also, I managed to resurrect my SSD with no data loss.

I'm working on reconfiguring the computer, it appears that the OBD2 connector was conflicting with the GPS and making the OS unstable.

More updates coming soon!

 

Mmm, blowing the dust off this project.


Prodded the computer back to life, having some major issues with CentraFuse, it just refuses to work with my GPS and OBD2 connector even though they work just fine outside of CentraFuse. Really unhappy with the purchase of CentraFuse.

Anyways, I re-wired the power lines to go along a different route than the audio cable to fix the humming sound. Seems to work fine now.

Also purchased 2 cams, 550line resolution, RCA plugs, hook-up to battery (going to have to read up on fuses for this I think) w/ mounting hardware, with 120mm and 280mm lenses (130 degree & 190 degree):

 

The cameras are 12Vdc. Build an adapter to pull the power off one of the drive molex connectors off your computer's psu. That way they'll get clean 12V and not the spiky 12-whatever your car's alternator will spit out.

 

Hmm, that's possible, but the computer's PSU will be way in the trunk and one of the cameras will be on the dash. Won't it cause a slight loss?

 

The cameras will use a small amount of current, so even with thin cable, the loss won't be much. Some good rca leads will do fine, especially since the power line will have an earth shield around it, so it can run side by side with the video cable, no probs

As Barry says, better to use the cleaner 12v from the pc psu.

And just to re-confirm, all the grounds/earths/negtives in the car are always connected, lights, cigarette lighters, the lot. It's the +12v that does the switching.