DashPC Startup and Shutdown Controller

This is an electronic circuit that I designed, built and brought to market. This page is here for posterity. The contents are from the original product page.

DashPC Startup and Shutdown Controller


The Dashwerks Startup and Shutdown Controller (DSSC™) helps you coordinate the startup and shutdown of your Carputer with your vehicle’s normal start and stop activity. A long asked question in the hobbyist carputer/telematics industry has been one of how to control startup and shutdown of the PC. Fortunately, the DSSC™ is now available to make car computer integration much easier.


  • 5 user adjustable timing controls - designed for vehicle controlled activation of computers, LCD display(s), peripherals, and amplifiers.

  • A “master power” relay (included) - using a powerful external 40A relay provides power to your carputer board, and all of the underlying peripherals (assuming their respective power requirements are met). This primary relay prevents dead car batteries by helping you intelligently manage your power distribution and device initialisation.

  • ACPI switch header - The ACPI header is a 2 pin connector that is designed to connect to the power connector on a computer [motherboard]. We designed this device to be flexible, and as such this header can easily be connected to other motherboard connectors - such as Wake-On-Lan (WOL) and Ring Indicator (RI). The vast majority of motherboards manufactured after 2001 support ACPI. As your vehicle is started this connector will toggle startup and shutdown on your car computer / DashPC™.

  • 5 Indicator LEDs - Designed for status and power indication (and timing adjustment), these leds help you tune the activation and de-activation of on-board devices. In addition, each of the 5 leds features a remote location header. These headers allow you to place the LED’s in locations that are suitable for your installation. Simply install (or have your installer) place a few led’s in your Dash, and connect them to the DSSC™ controller. From your dashboard you’ll instantly know what state your computer / amps / peripherals / etc. are in.

  • “Shutdown” Function - The shutdown function provides 2 methods of properly halting a car computer: the text “SHUTDOWN” will be sent to a serial port when the key is removed from the vehicle (ACCessory line goes low). In addition, an ACPI 1.0 and up compliant signal can be used to power down a computer. Virtually all computers manufactured in the past 5 years are compatible with ACPI. If your computer can “hibernate” or “suspend”, the DSSC™ can be used to safely shutdown your Car PC.

  • Serial port connector - this serial port connector provides an alternate method of shutting down a car computer / DashPC™ unit. By connecting this port of the DSSC™ to an industry standard computer serial port your computer can be halted safely (driver software may be required). Halting your carputer / DashPC™ properly prevents data loss, drive corruption and hardware failure.

  • Reverse Polarity Protection - The DSSC has reverse polarity protection built-in. If someone accidentally reverses the wiring of the DSSC, it won’t destroy the board.

  • Tuning mode - By enabling a jumper on the board, you can put the board into a ‘tuning’ mode. Using the tuning mode you can adjust the timing of the devices without actually toggling them on and off. The tuning mode is a great way to make sure that your devices are turning on in the fastest possible time without actually toggling them on and off.


The DSSC™ is compatible with Windows XP, 2000, ME, 98 and Linux and MacOS X. Any operating system that supports hibernate, suspend and/or sleep can be used with the DSSC. Software drivers for the Serial Port shutdown function are provided for Linux, Windows XP, and Windows 2000. A computer does not need to be ACPI compliant to work with the DSSC. If the computer can be configured to boot on powerup (typically this is set in the BIOS), it will work with the DSSC.

Product Comparison

The DSSC is the only Startup/Shutdown Controller that was developed by Carputer enthusiasts for Carputer enthusiasts. Over 2,400 users helped us design the DSSC with the features that are most important to them. How does the DSSC™ compare to other Startup/Shutdown Controllers? Click here to see how suitable the DSSC is in our product comparison chart.

Installation Diagrams

Application Note #1: Installation with Inverter and ACPI Compatible computer (ATX, ITX, Via Epia, etc)

Typical installation with an inverter

Application Note #2: Installation with Inverter and computer using Serial Port for shutdown (notebooks, etc)
Application Note #3: Installation with DC/DC Power Supply and ACPI Compatible computer (Carnetix, Opus, etc)
Application Note #4: Installation with DC/DC Power Supply, recent motherboard and Multiple Car Batteries (ATX Motherboard, Via Epias, etc)

Purchasing Information

$49 USD

This product is discontinued.

Customer Support

To discuss the DSSC circuit in the user forum - ( Click Here )
To view the online user’s manual (156k PDF) - ( Click Here )

Software Drivers

Click here to download the DSSC Service for Windows 98, 2000, XP (Thanks to Kevin Lincecum (aka Frodo) for this).
Click here to download the DSSC daemon for Linux (written in Perl by Chris Bergeron).


Shipping to the continental United States is $5.95. We also ship internationally! ( additional shipping fees apply ).

Sales / Customer Support

For questions or customer support, please dial 877-810-8128 or 678-291-1255. We can also be reached via e-mail.
Information related to IP licensing of DSSC™ technology can be found by clicking here.


Chris Bergeron

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