Beaglebone Black, ANT+, and Garmin FR70

My BBB is running Debian. Your mileage may vary if your BBB is running the stock Ångström.

Just successfully extracted data from my Garmin FR70 to BBB via a Garmin ANT+ USB stick. The steps are quite simple once you figured what software you need.

Note that different version of Garmin products use different protocol to communicate. The program Garmin-Forerunner-610-Extractor supports the followings:

 - Garmin Forerunner 60
 - Garmin Forerunner 405CX
 - Garmin Forerunner 310XT
 - Garmin Forerunner 610
 - Garmin Forerunner 910XT
 - Garmin FR70
 - Garmin Swim

Basically you just follow the instructions on the page. To sync with your BBB the first time, remember to turn on the Pairing function on you device. On my FR70, it is under Settings > System > Computer > Pairing.

For other devices

If you are using other devices that are not supported by Garmin-Forerunner-610-Extractor, go check out garmin-ant-downloader (this can be installed via apt-get). If you are using garmin-ant-downloader, your may need to create the USB serial device manually on your BBB. After you plugged in the ANT+ USB stick, use the lsusb command to list the device:

debian@debian-armhf:~/garmin$ lsusb
Bus 001 Device 002: ID 058f:6254 Alcor Micro Corp. USB Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 154b:0062 PNY
Bus 001 Device 008: ID 0fcf:1008 Dynastream Innovations, Inc.

The last device is my ANT+ stick. The garmin-ant-downloader needs to access the stick via a serial device. By default, it is the /dev/ttyUSB0. If it is not created automatically, use the following command:

sudo modprobe usbserial vendor=0x0fcf product=0x1008

Where 0x0fcf and 0x1008 are the code from the lsusb command result. Use the values that correspond to the output of your stick.

Using Oracle JDK 8 for ARM Early Access VM in OpenJDK under BeagleBoneBlack

Note that Oracle 8 JDK official release for ARM is out.  There is no need to follow the steps below.  Also, if you want to install it via apt-get, you may refer to this link.

Following similar instructions for Raspberry Pi, here are the instructions on how to boost the Java performance on BeagleBone Black by using Oracle's JDK 8 Early Access HotSpot with OpenJDK.

Note that I am using Debian on my BBB

Install openjdk

/mnt/usb/debian/test$ sudo apt-get install openjdk-7-jdk

Optional. Download a benchmark program. Save it as fastaredux.java and test the performance of the stock OpenJDK.

/mnt/usb/debian/test$ java -version
java version "1.7.0_03"
OpenJDK Runtime Environment (IcedTea7 2.1.7) (7u3-2.1.7-1)
OpenJDK Zero VM (build 22.0-b10, mixed mode)
/mnt/usb/debian/test$ javac fastaredux.java
/mnt/usb/debian/test$ time java -XX:+TieredCompilation -XX:+AggressiveOpts fastaredux 25000000 > /dev/null 2>&1

real    1m40.294s
user    1m40.047s
sys     0m0.180s

Download the JDK 8 for ARM Early Access package from Oracle web site.

Following the instructions, extract the hotspot VM and add it to OpenJDK

/mnt/usb/debian/test$ tar --extract --verbose --file=jdk-8-ea-b36e-linux-arm-hflt-29_nov_2012.tar.gz jdk1.8.0/jre/lib/arm/client
jdk1.8.0/jre/lib/arm/client/
jdk1.8.0/jre/lib/arm/client/Xusage.txt
jdk1.8.0/jre/lib/arm/client/libjvm.so
jdk1.8.0/jre/lib/arm/client/libjsig.so
/mnt/usb/debian/test$ sudo mv jdk1.8.0/jre/lib/arm/client /usr/lib/jvm/java-7-openjdk-armhf/jre/lib/arm/oracle
/mnt/usb/debian/test$ sudo chown -R root:root /usr/lib/jvm/java-7-openjdk-armhf/jre/lib/arm/oracle

Make the HotSpot VM as our default VM. Edit the file /etc/java-7-openjdk/jvm-armhf.cfg and add -oracle KNOWN as the first parameter. (or, as stated in the instructions, use the sed command to add it to the first line of the file)

-oracle KNOWN
-server KNOWN
-client IGNORE
-hotspot ERROR
-classic WARN
-native ERROR
-green ERROR
-zero ALIASED_TO -server
-cacao KNOWN
-zero ERROR
-shark ERROR
-jamvm KNOWN

Note the last line of the output. Now it changed to use HotSpot VM

/mnt/usb/debian/test$ java -version
java version "1.7.0_03"
OpenJDK Runtime Environment (IcedTea7 2.1.7) (7u3-2.1.7-1)
Java HotSpot(TM) Client VM (build 25.0-b04, mixed mode)

Result of running the same benchmark. The performance almost tripled.

/mnt/usb/debian/test$ time java -XX:+TieredCompilation -XX:+AggressiveOpts fastaredux 25000000 > /dev/null 2>&1

real    0m35.102s
user    0m34.906s
sys     0m0.166s

Note that using the -server option on the HotSpot VM seems to slow down the performance though.

Using the -server option will actually switch back to use the default OpenJDK Zero VM

$ java -server -version
java version "1.7.0_03"
OpenJDK Runtime Environment (IcedTea7 2.1.7) (7u3-2.1.7-1)
OpenJDK Zero VM (build 22.0-b10, mixed mode)
$ java -version
java version "1.7.0_03"
OpenJDK Runtime Environment (IcedTea7 2.1.7) (7u3-2.1.7-1)
Java HotSpot(TM) Client VM (build 25.0-b04, mixed mode)

You can also alias -server option to use HotSpot VM:

-oracle KNOWN
-server ALIASED_TO -oracle
#-server KNOWN
-client IGNORE
-hotspot ERROR
-classic WARN
-native ERROR
-green ERROR
-zero ALIASED_TO -server
-cacao ERROR
-zero ERROR
-shark ERROR
-jamvm KNOWN

PS. Here is the before vs after result on my Raspberry Pi.

Before:

pi@raspberrypi ~/test $ time java -XX:+TieredCompilation -XX:+AggressiveOpts fastaredux 25000000 > /dev/null 2>&1

real    8m4.807s
user    7m56.410s
sys     0m1.880s

After:

pi@raspberrypi ~/test $ time java -XX:+TieredCompilation -XX:+AggressiveOpts fastaredux 25000000 > /dev/null 2>&1

real    0m44.109s
user    0m43.160s
sys     0m0.320s

OpenCV facial recognition with BeagleBone Black

After flashing my BBB with Debian, I proceed to install OpenCV and the required Python packages. Using the sample code from here, I could get the facial and eye recognition demo running in a few minutes!

A few points to note:

• I am running Debian Wheezy on my BBB with the image flashed to eMMC. It is a headless setup. Connect to it from my Windows PC using putty and Xming
• BBB seems to be having problem when the webcam resolution is too high. The sample code ran OK when the witdth and height set as 320x240 or 352x288
• For the facial recognition sample, some external XML files are required. You may get them from the OpenCV source code package. Just modify the sample code to point to the correct directory

Ångström...

I think I will give up Ångström and flash Debian Wheezy onto the eMMC of my BeagleBond Black directly...

Upgrading Ångström on Beaglebone Black

Got my BBB a few weeks ago. My first attempt to update and upgrade the stock Ångström failed. I knew that the in memory /tmp is not big enough for "opkg upgrade" to store the downloaded packages. So I added the "-t" switch to write the temp files to another directory.

However, even the BBB eMMC is not big enough. The upgrade failed and probably corrupted the base. Needed to re-flash the eMMC.

Notes to self: Plug in a USB stick and use it as temp storage for "opkg upgrade" next time!!