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EETE FEB 2016

ENWS & ETCHLNOGY Sponsored Contributed Article Beagle Bone Green vs. Black: a Side by Side Comparison By Lynnette Reese, Mouser Electronics Open source hardware (OSHW) has created a new paradigm in embedded engineering. Science used to be freely shared, then everything became copyrighted, patented, or proprietary. OSHW is a new way to market microcontrollers, educate people, and share ideas, methods, and schematics freely. A new OSHW single board computer has arrived: the Beagle Bone Green (BBG), an off-shoot of the Beagle Bone Black (BBB). Several tables below include the basic facts necessary to quickly compare these two boards. Figure 1: The Beagle Bone Green from Seeed Studio is in stock now at Mouser.com Beaglebone Green is a well-planned update to Beaglebone Black, and has the same 32-bit Sitara™ ARM® Cortex®-A8 processor that runs up to 1GHz with 512MB RAM. BBB came out in 2013, so there’s a good amount of communityshared software that works on both. BBG ships with Debian Linux, and costs about 20% less than the Black. (Both boards qualify as a bonafide Linux box.) Most changes from BBB to BBG are in peripherals. BBG supports both capes and opensource, click-in “Grove” modules from Seeed Studio. BBG does not have HDMI, although since BBG also supports capes, a work-around is possible. The 5V power jack has been replaced by microUSB (μUSB) for BBG power, and there’s an RTC with battery backup. For     Beaglebone  Black    (BBB)  -­‐  Rev  C   Beaglebone  Green  (BBG)     Board  Dimensions   3.4"  (L)    x  2.1"  (W)     3.4"  (L)    x  2.1"  (W)  x  .75"  (H)     (Height  is  with  micro  USB  cable  plugged  in)   Board  Weight   1.4  oz  (39.68  g)   Same  as  BBB   Printed  Circuit  Board   6  layer  PCB   Same  as  BBB   Processor   Texas  Instruments  Sitara  AM3358BZCZ100  RISC      Same  as  BBB     Description  of  Processor   3D  graphics  processing,  peripherals  &  industrial   interfaces  (see  below).  Supports  high-­‐level   operating  systems  (OS)  Linux®  and  Android™.   Standby  power  draw:  ~25mW,  Deep  Sleep:  ~7mW   Same  as  BBB   Architecture    Sitara™  ARM®  Cortex®-­‐A8     Same  as  BBB   Speed   1  GHz  Max   Same  as  BBB   Width,  Instruction  Set   32-­‐bit   Same  as  BBB   Real  Time  Clock  (RTC)   No    Yes,  with  battery  backup   Watch  Dog  Timer   Yes,  but  must  be  initially  activated  by  writing  to   /dev/watchdog.  Reset/reboot  default  is  60  sec.   Same  as  BBB   Cache    32KB  of  L1  Instruction  &  32KB  of  Data  Cache     Same  as  BBB   RAM   512MB  DDR3     Same  as  BBB   Storage   *  BBB  Rev  C:  4GB  eMMC  on-­‐board  flash  storage   *Micro  SD  card  slot   *A  single  256Mb  x16  DDR3L  4Gb  (512MB)  memory   device  is  used  on-­‐board  in  BBG   *Micro  SD  card  slot   EEPROM   4KB   Same  as  BBB   External  Storage   Micro-­‐SD-­‐card  &  support  for    an  external  USB2.0   drive   Same  as  BBB   Video  Support   HDMI   Via  add-­‐on  cape  as  a  workaround   Audio  Support   Yes,  via  HDMI  (stereo)   No;  maybe  via  cape/USB  audio  card  -­‐  untested.     Status  Indication   1  -­‐  Power  on  LED   2  -­‐  Ethernet  LEDs  located  on  the  RJ45  (Yellow  for   Link  up  if  on,  Green  flashing  for  traffic)   4  -­‐  User-­‐defined  LEDs  via  setting  GPIO  pins   Same  as  BBB   JTAG   Built-­‐in  JTAG  emulator  via  USB.  See  "Getting   started  with  JTAG  and  CCS"   http://beagleboard.org/static/Docs/ccs-­‐jtag-­‐ simple.htm   Built-­‐in  JTAG  emulator  via  USB.  See  "Getting  started   with  JTAG  and  CCS"  Same  address  as  on  left.   A  place  exists  for  an  optional  20  pin  CTI  JTAG   header     Serial  Debug   Serial  port  is  available  via  the  J1  header,  using  the   FTDI  USB  to  Serial  adapter.  (Only  pins  1,  4  and  5  are   connected  on  the  board,  so  Vcc  on  pin  3  of  the  FTDI   adapter  does  not  affect  the  Beaglebone.)   Serial  debug  is  provided  via  UART0  on  the   processor  via  a  single  1x6  pin  header.  In  order  to   use  the  interface  a  USB  to  TTL  adapter  is  required.     Module  Compatibility   Capes   BBB  compatible  Capes  and  Grove  modules  by   Seeed  Studio  (www.mouser.com/seeed-­‐studio-­‐ grove)   Analog  I/O   7  pins  (  AIN  pins  are  rated  0  -­‐  1.8V  only)   Same  as  BBB   Digital  I/O  (aka  GPIO)   65  pins  (rated  0  -­‐  3.3V  only)   Same  as  BBB   PWM   8  total.   Same  as  BBB   Table 1:     Beaglebone  Black   Beaglebone  Green   DC  Power  Supply  (VIN)   *5V  barrel  jack     *MiniUSB     *5VDC  via  expansion  header  (5V  @  1A  max)   *USB  port  on  a  PC   *A  power  supply  with  a  USB  connector.   *External  Power@5  volts  via  P9  Expansion  header   VDD_5V  pin    (5V  @  1A  max)   Ethernet  cable   Cat5e/Cat6;  not  included.   Cat5e/Cat6;  not  included.   USB  2.0  type  A/B-­‐micro  cable   Included,  a  6-­‐inch  long  A/B  micro  cable.     Included,  a  6-­‐inch  long  A/B  micro  cable.     SD  Card   MicroSD  card,  not  included.   MicroSD  card,  not  included.   Powered  USB  Hub   Not  included.  Recommended  to  power  any  USB   peripherals  that  would  take  current  draw  above   500mA,  since  a  regular  USB  port  has  a  maximum  of   500  mA.  (E.g.,  wired  mouse,  keyboard)   Same  as  BBB.   Table 3: Board Requirements 12 Electronic Engineering Times Europe February 2016 www.electronics-eetimes.com


EETE FEB 2016
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