The operating system image that comes with this book is supposed to work on either the BeagleBone White or the newer BeagleBone Black. The black uses some of the I/O for the LCD display and the eMMC chip; so in order to make the alarm system hardware work with either version, we must take care not to use any of the I/O used by the black.

The pins marked with an * are the ones currently used by the software in this book.

Pins that are marked as Not Used should be safe for you to use for future expansion, subject to changes in the Kernel (if you upgrade).