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ButterflySDC Project Homepage

The Butterfly SDC (or Shut Down Controller) is a piece of hardware specifically designed to manage the power state of an ATX/ACPI compliant computer motherboard when used in a 12 volt enviroment such as in an automobile. More information about "Carputers" can be gleaned in the messageboard at mp3car.com. This project can be built for around $50 and is simple enough that the average hobbyist should be capable of successfully producing one. There are plans to design an etched, pre-fabricated PCB (printed circuit board) that would make this far less complicated to the novice electronics hobbyist. If you would be interested in purchasing a DIY kit, please contact me so I can guage the demand.

Here are a few preliminary pictures of the initial prototype

ButterflySDC's firmware is based on the Butterfly GCC port by Martin Thomas and is licensed under the GPL V2, if you download the source please read the included license.txt file for information regarding distribution and use.

Videos of the controller in action. Many thanks to my son Josh for his assitance with the ignition switch! Sorry for the shaky camera work, we were in a hurry and didn't feel like setting up the tripod.
bfsdc_manual_shutdown.avi
bfsdc_menus.avi
bfsdc_start_sequence.avi
bf_sdc_LED_legend.jpg

Changelog
12/12/2007 - 0.9.3 beta - circuit revision 1.2

added low voltage shutdown limit and voltage sensing calibration
added hi-temp 'off' setting to disable overtemp protection

12/11/2007 - 0.9.2 beta

added high and low temperature limits

12/7/2007 - 0.9.1 beta

ported in changes for lib-avr 1.4.5 support (sleep mode & other fixes)

12/6/2007 - 0.9.0 beta - circuit revision 1.1

revised circuit design to swap power good input line to JTAG pin 1 so the USI pin 2 could be used for the aux switch input due to interrupt limitations (interrupt is not needed for the power good input)

! IMPORTANT NOTICE !
if you've built a butterflySDC based on circuit design 1.0 you will need to swap pin 4 of the 7404 hex inverter from USI pin 2 to the JTAG connector's pin 1 before using v 0.9.0 or newer firmware

1/19/2007 - v. 0.8.1 initial public release
Note: see readme.txt for details about building the project

Downloads

Minimal Plans - All the average hobbyist should need to build one.
bf_sdc-0.8.1-minimal.zip
bf_sdc-0.9.3-minimal.zip

Complete Source and Schematic - If you want to customize the firmware or just learn more about how it works.
bf_sdc-0.8.1-full.zip
bf_sdc-0.9.1-full.zip
bf_sdc-0.9.2-full.zip
bf_sdc-0.9.3-full.zip