Audio/video group
You’ll want to spend some time thinking about how you’ll use your Car PC before you settle on the design for the audio and video interfaces, because they’re part of the user interface as well as the output devices for sound and video. Here are some points to consider:
Wiring — Connecting the PC audio outputs to the car’s stereo is much better than adding a second set of speakers and amplifiers, so much so that you’re better off upgrading those components if necessary versus adding the second set. You can hardwire the connection, which requires running properly grounded, shielded cables from the PC location through the passenger compartment to the head unit, or you can install a small FM transmitter to link the PC wirelessly to the head unit.
Display — Assuming you have a display at all, you won’t want its resolution to be less than 640 ? 480, and you’ll need 800 ? 600 to run Windows XP. Cathode ray tubes (CRTs) are impractical for a car — desktop CRT monitors simply won’t stand up to the shock, vibration, and temperature extremes. LCD panels are readily available at those resolutions; look for ones between 7 and 9 inches, diagonal measure.
Display integration — If you want multiple displays but not multiple PCs, such as for playing DVDs on the back seat display while you navigate from the front display, you’ll have to consider how the displays integrate with the operating system and your control software.Windows combines multiple displays into a single desktop surface, but most software is relatively brain-dead about working with desktops spanning multiple displays.
Controls integration — You shouldn’t try to use either a keyboard or a mouse while driving, nor a handheld remote control. The section on sensors describes how to integrate a keyboard and mouse; nevertheless, a touch panel is better, the built-in stereo controls are even better, and (done well) voice command is probably best. The section on software discusses approaches to build voice command software under Windows.