Beaglebone.org’s $45 BeagleBone Black module runs a 1-GHz Texas Instruments AM3359 processor based on an Arm Cortex-A8 core (Fig. 1). It’s faster than the original BeagleBone (see “BeagleBone Features Sitara AM335x ARM Cortex-A8 Microprocessor” at engineeringtv.com), but it uses less power. BeagleBoard demonstrated how the Black can run off the USB connection at Design West in San Jose.
The AM3359 is a multicore device. In addition to the Cortex-A8, it has two programmable real-time units (PRUs) designed for peripheral control. These PRUs have their own RAM and can be programmed in PRU assembler. They also can handle chores like motor control offloading the host processor. The module includes a Cortex-M3 used for power management. And, it can provide secure boot capability.
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The platform comes with Angstrom Linux in an on-board 2-Gbyte eMMC memory chip. The BeagleBone Black still has a MicroSD slot, but eMMC is faster and more reliable. The eMMC is large enough to run a number of operating systems including Ubuntu Linux and Android. The switch to eMMC also saved money because the platform no longer comes with a MicroSD flash card.
The module has 512 Mbytes of 400-MHz DDR3 memory, which reduces power consumption while improving performance. It also has a microHDMI socket as well as USB host and client interfaces. It comes with a USB cable and a 10/100 Ethernet port, but no Ethernet cable. The pair of headers provides access to the chip’s other interfaces.
The headers allow “capes” or expansion boards to be plugged into the BeagleBone Black. Capes will work with either BeagleBone. The wide variety of available capes includes open-source hardware designs. The BeagleBone design is also open source. Furthermore, the system supports serial debug. Cost savings led to the elimination of the JTAG header, but one can be soldered on if necessary.
The BeagleBone Black has Yacto project support as well as support for devicetree.org. The Yacto project is designed to bring commonality to embedded Linux. Devicetree.org provides a standard for defining device interfaces that would be portable across operating systems. The focus of the BeagleBone is education. It will be part of the Google Summer of Code 2013 event.
What is most impressive about getting started with the BeagleBone is Bonescript and the Bonescript Web site. The module comes with a browser that runs Bonescript and has remote processor calls (RPCs). The neat thing about this demonstration was how the Web site interface allows a user to control the module and do things like toggling LEDs.
The BeagleBone competes with popular platforms like Raspberry Pi (see “Hot Raspberry Pi” at electronicdesign.com) and higher-end Arduino modules like those based on Microchip’s 32-bit, MIPS-based microcontroller (see “PIC32 Arduino Modules” at electronicdesign.com).