GPS Hardware

Computer - Cappuccino SlimPro-300

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This small Pentium III based PC has the important features: USB, FireWire, Serial, and 2 IDE ports.  Chosen for its size, I populated it with a PIII 1.0 Ghz, 256MB ram, 60GB 2.5" HD, PS/2 ports for mouse and keyboard, and 1GB Compact Flash.  Video is through the Intel 855 chipset and audio was inconsequential, as it does not provide Dolby Digital.  I was able to rewire the power and reset switches as well as tap into another serial port and provide regulated low voltage power for the GPS all from this unit.  This was bought from Cappuccino PC.

Admittedly, this final platform took some work.  I fabricated a mounting fixture for the compact flash/IDE adapter, and tapped holes in the side of the PC to allow for car mounting (see installation page). The rewire for the serial port took some inference and meter work, and configuration of the BIOS for booting the CF was not the most straight forward.

311_ACS-CF-IDEToCFA-SFF-REV2_TOP Most important is the Compact Flash adapter requiring a 44 pin IDE cable which swaps all the lines.  This makes it possible to work with the IDE interface in the SlimPro.  Looking at the pins, one can see why this is necessary.  Oh, and not all CF cards are not created equally.  The Sandisk Ultimate II card, which has the correct IDE chipset allowing it to boot a PC.  I bought this adapter from from ACS, which is the best place in my opinion to get one.  Those guys really know what they are doing.

Is the video fast enough?  Yes.  Is the system fast enough? Yes.  With the right OS, this system can rip dvds, playback vobs from the HD, navigate with GPS and provide Dolby Digital Output simultaneously.  Is that fast enough?  I finally upgraded to 512 MB ram, but it didn't seem to make much of a difference.

Power must be supplied +/- 5%, so direct battery hookup is not possible.  This drove the requirement for the power supply listed below.

Keyboard and mouse

Um, yeah.  Eventually this became necessary.  I chose to use an IBM RF wireless keyboard and mouse/joy combination.  However, since the unit runs with a touchscreen, I leave the keyboard at home, and am 100% happy without it.  The transmitter stays in the car, but hte actual keyboard stays in the garage.

DVD - Panasonic CW-8124

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A combination DVD-ROM CD-RW which provides the needed media playback.  This particual drive is slot loading (which is what I think is required in a car), and is of course a slim model for a laptop.  I luckily fell onto the drive chassis shown, which beyond my expectations provides USB2.0 and IEEE1394, both bus powered, and is very close the dimensions of the drive.  Ideally, this would have been a DIN mount system, but this works well too.  Both the drive and chassis are great solutions and provide a great portable fast DVD/CD.  The chassis and drive are permanently mounted in the vehicle.  I bought these both from mp3car.com.

Display - DWW-700H

DWW-700H_open_side1A touchscreen is a must for car computing.  No keyboard or mouse were acceptable, as they provide too much distraction.  This particular 7" unit flips down and pushes into the dash, is non motorized, and is single DIN mounted.  It was purchased from digitalww.

I wish I could offer advice on the selection of a screen or touchscreen.  The DWW-700H is very clear, and the USB touchscreen is extremely reliable at all temperatures (at least for me).  This, however, was not my first screen.  I tried a liliput 8", and could not get the touchscreen to maintain calibration.  This was not a problem with the DWW-700H.  Uses VGA for video, or can use composite input.  USB powers the touchscreen, so it can be used, even when the screen is off (this seems somewhat standard).  

There are problems with this unit though.  1. No auto on feature.  2. Takes a long time to turn on (5 seconds after power, plus 5 seconds after button is pressed).  3. Screen stopped working for no reason, and required taking it apart.  Luckily, while probing the microcontroller, I realized the chip socket was flaky, and stretched the pins.  Since, it has not been a problem.  I decided to power this from the power supply listed below, since I can cut power when I want.

Power Supply - Carnetix CNX-1260

p1260A power supply is required for anything in the car.  Why?  Because the battery voltage in a car can be anywhere from 11 to 14 volts, and the computer cannot take this.  Basically, this unit is a DC/DC converter with off timer and control inputs.  This 60 watt model powers the computer and display directly, and indirectly the GPS, DVD chassis, and USB Sound card.

I connected this unit to a custom harness I made, and a set of switches to turn on/off the power supply.  Power input is wired directly to the car battery through a 6 amp fuse.  For installation or buy one yourself, go to mp3car.com.

Power Interface

This is a custom made device with IR input and switches to control the power supply and PC.  Pictures and better description to come.

GPS - GlobalSat BR-355

semsons-inc_1995_5619321Choosing the right GPS is important.  Acquisition time, accuracy, and interface are primary concerns.  I chose this unit for price, accuracy, and its serial interface option.  It also happens to have some of the fastest acquisition times I've experienced in a GPS.  It also features a magnetic base, and separate power connection allowing for flexible in-dash mounting and powering.  I bought this from BuyGPSNow.

Sound - Soundblaster Live/!24 bit USB

prodimg_live_24-bit_exCheap and provides dolby digital.  In fact, the most important features were USB, Dolby Digital, and SPDIF.  Why SPDIF?  Becuase the industry standard for dolby digital, even in mobile applications, is SPDIF.  The SPDIF on this soundcard is great since it is optical, and does not incure the ground loop hum many people experience with their setups.

Until you try it, you will not realize how hard dolby digital (5.1) sound is in an automobile.  DVD head units do not have SPDIF inputs nor do they accept AC3 audio.  In any installation, a DSP is required to decode the AC3 audio compressed format.  I bought the automotive DSP from Alpine.

This soundcard is available from most hardware vendors.

DSP - Alpine PXA-H510

autoMobile_AV_SystemsAllAlpineAlpine_PXAH510-resized200This was an Ebay purchase, and is an incredible find.  Dolby Digital Optical SPDIF as well as line level inputs from another source.  This unit even switches between inputs automatically, and sets the optical SPDIF as a priority over all the other inputs.

As a bonus, this unit allows for each speaker to be configured with an equalizer.  Incredibly, it also provides a phanton center channel, eliminating the need for another speaker (which I didn't know how I would mount).

Manuals for this unit are here, and here.  Power comes form the car battery and the small control panel shown in the picture is on a 6 foot cable.  To be honest, this thing is awesome, and only cost about $200.  It may have made the difference in this whole installation, as the sound is clear and clean, and well balanced.  An amplifier is required to power the speakers.

Amplifier - Hifonics Zeus ZX8000

cachedimageservice 5 channels, 4 x 50 watt + 1 x 200 watt.  I wired it in a standard single output configuration, one out to each speaker and a subwoofer.  Input is through a dedicated 30 amp circuit direct to the battery.  This amp was cheap at $200, and prrovides outputs for each of the dolby digital speakers.  

Best yet was the low Total Harmonic Distortion ( < 0.05%), which in my opinion is best for Dolby Digital Audio.  This amp was purchased new from the web.

SubWoofer - Pioneer TS-W250R

I bought a simple 10" subwoofer and box from Best Buy.  Easy installation, nothing too customized here, but provided the well needed bass missing form the sound.

Head Unit

I bought a simple head unit from JVC.  Crutchfield purchase to provide radio and CD when not using the computer.  Most important, it has line pre-outs which were compatible with the line inputs of the DSP.

Wire

One word: Radioshack.  Go there, get wire, be happy.  I actually ordered connectors for my custom harnesses from digikey, but all the wire came from RadioShack.  I used 10 guage for all the speakers and the least expensive RCA phono cables from the shack.  Optical cable also came from the shack, cheapest place I could find.