Introducing the BBB

From the BeagleBoard website (BeagleBoard.org ), which is the nonprofit foundation behind BeagleBoard-xM, BeagleBone, and BBB, the BBB is a low-cost, community-supported development platform for developers and hobbyists. The Rev C, which is the latest revision, has impressive specifications including the TI Sitara AM3358 1GHz ARM Cortex-A8 processor, 512 MB of DDR3 RAM, and 4 GB Embedded Multi-Media Card (eMMC) for on-board flash. When you take a look at the board, you'll see two 46-pin expansions headers. If you compare it to other hobbyist boards around the same price point, you'll come to the conclusion that the other boards do not contain nearly as much expansion capability. The BBB supports many more Input/Output (IO) options, including three I2C buses, multiple serial ports, 65 General Purpose IO (GPIO), multiple Pulse Width Modulators (PWM), and seven analog inputs with built-in Analog-to-Digital Converters (ADCs). If you don't know what all of these are, that's not a problem, as we'll explain the systems that we use throughout the projects.

The quality of the documentation from BeagleBoard.org is outstanding. You should read the BBB System Reference Manual (SRM), the official manual for BBB, which is located at https://github.com/CircuitCo/BeagleBone-Black/blob/master/BBB_SRM.pdf?raw=true. This is a complete manual that covers connecting the BBB, power options, and boot sequences. Many of the questions asked on the BeagleBoard mailing list and IRC channel can be quickly answered in this manual. The author of this book assumes that you've at least skimmed sections 3, 4, and 5 of the SRM, which means you are aware of the basic capabilities of BBB and are familiar with the physical connectors. There is simply no better reference for the BBB than this document.

Appreciating BBB's commitment to open source hardware

BBB has another very important quality: it is Open Source Hardware (OSHW). OSHW is a relatively new concept, the exact definition of which may confuse people. However, there is a group, the OSHW Association (OSHWA), whose mission is to educate and promote OSHW. Their definition is maintained on their website: http://www.oshwa.org/definition/. As with most organizations, a consensus for a definition can be difficult to obtain. The definition of OSHW is well over a page. The complication with defining OSHW from open source software is that hardware is a physical thing. There are design files to manufacture hardware, but there are physical components also. To make a software analogy, the compiler for the hardware is the manufacturer. Therefore, the definition of OSHW is carefully constructed and it generally applies to the design files of the hardware.

Note

Alicia Gibb, the Executive Director of OSHWA, gave a TEDx talk called The Death of Patents and What Comes After (https://www.youtube.com/watch?v=z__Sbw1Ax4o). The talk illustrates how hardware design straddles both copyrights and patent law. Alicia also provides some interesting insights on the incentives behind patents and OSHW.

BBB is OSHW, in that it releases documentation, schematics, Computer-Aided Design (CAD) files, Bill Of Materials (BOM), and production files (Gerbers), all under a Creative Commons license. This means that you can not only study the complete design but you are also free to make your own derivative BBB.

Unboxing the BBB and providing power

Unlike Raspberry Pi, BBB is ready out of the box. A recent BBB will come with the Debian distribution of GNU/Linux, henceforth referred to as Debian, installed on the eMMC. eMMC is the on-board flash memory for the BBB. As soon as power is applied to the board, BBB will start to boot from the eMMC. As shown in section three of the SRM, you can connect the BBB directly to your PC with the supplied USB cable. The BBB can also be powered from a 5V barrel jack, where you'll want a wall adapter that can supply up to 1A. If you plan on connecting a mini liquid-crystal display (LCD) to the BBB, you may want to use a 2A adapter. You can typically find the output voltage and amperage specifications written on the adapter. You can tell whether the board is powered and running if the blue user light-emitting diodes (LEDs) are flashing. Specifically, the LED USER0 will flash in a heartbeat pattern.

Note

Each user LED has a default meaning that corresponds to a specific BBB activity. To further motivate you to read the SRM, the meanings are defined in section 3.4.3 under step 6, Booting the Board.

Tip

Be very careful when choosing your power supply. The BBB needs 5VDC +/-.25V. Connecting a higher voltage power supply will damage the board.

The BBB can support multiple peripherals such as a keyboard, mouse, and monitor. However, in this book, we'll be using the BBB in a headless configuration, which means without the monitor. Section 3 of the SRM details the various connection scenarios.