Book Image

Building a Home Security System with BeagleBone

By : William Pretty
Book Image

Building a Home Security System with BeagleBone

By: William Pretty

Overview of this book

One of the best kept secrets of the security industry is just how simple the monitoring hardware actually is - BeagleBone has all the computing power you need to build yourself an extremely sophisticated access control, alarm panel, and home automation and network intrusion-detection system. Security companies make a fortune each year by charging exorbitant fees to their customers. You will learn how easy it is to make an alarm system with Beaglebone. A company-maintained-and-monitored alarm system has its place - your dear old mum is probably not going to be creating her own system any time soon. But if you are reading this book, you are probably a builder or a hobbyist with all the skills required to do it yourself. With Building a Home Security System with BeagleBone, you will learn everything you need to know to develop your own state-of-the-art security system, all for less than a year's worth of monitoring charges from your local alarm company! You will start by building and testing your hardware and open source software on an experimenter's prototype board before progressing to more complex systems. You will then learn how to test your new creations in a modular fashion and begin to utilize BeagleBone. Once your system is built and tested, you will install some of the professional-grade sensors used in modern alarm systems and learn how to use them. You will also discover how to extend your alarm system in a variety of different ways. The only limit will be your imagination.
Table of Contents (16 chapters)

The DC-motor driver


The DC-motor driver circuit will drive two DC motors, and unlike the solenoid driver, this board can control the motors separately. You can also connect it directly to the 3.3V outputs of the BeagleBoard adapter board. The PCB has been designed so that it fits between connectors J8 and J9 on a BeagleBone prototype board. Expansion boards are stackable on the BeagleBone, so it should be possible to put this board above or below your alarm system boards.

The DC motor control board

In this case, the motor will be powered continuously as compared to the solenoid, which is pulsed. For this reason, it will be a good idea to install a heat sink on U2.

In the preceding diagram, you will notice that the motor driver IC, U2, has two VCC inputs. The VCC input is the power supply input to an IC, which normally has only one supply input. The great thing about SN754410 is that it has two supply inputs. One for the control logic, in this case 3.3V, and one for the output driver circuit...