Rob Murrer

This post will enumerate and explain the steps that were taken to configure the Beagle Bone Black (BBB) for development of the iLidar cape. The commands on the host computer will be run on Mac OS X. Some details of the installation of the BBB drivers are omitted, this post assumes the user has already installed all the necessary drivers for the BBB and knows how to use the command line interface (terminal).

To configure the BBB, the following must be performed:

1. Install operating system
2. Install 3rd party software
3. Customize settings

Install Operating System

The default operating system (OS) for the BBB rev. C is the Debian Linux Distribution. Ubuntu was chosen to replace Debian. Ubuntu is Debian based, but is more familiar to me and seems to have a new version of Vim in its apt-cache.

Acquire and Flash Image

There are two ways to run an OS on the BBB. From the SD card or the eMMC which is the onboard flash. eMMC performance is much better so that is what is being used.

The disk image to be flashed to the eMMC changes periodically so check here for the latest version. Currently, as of August 21, 2014, this is the latest version.

Once the image is downloaded decompress image:

unxz BBB-eMMC-flasher-ubuntu-14.04-console-armhf-2014-08-13-2gb.img.xz

Insert a MicroSD card and determine which disk it is by using

diskutil list

If you are having problems figuring out what disk it is, rerun the command before and after plugging in the drive. Once the correct disk has been identified, you are ready to flash the image. Be sure you have the correct disk number, if not, you could overwrite another drive. Flash the card replacing the N with whatever disk number was determined in the previous step. This could take up to 30 minutes.

diskutil unmountDisk /dev/diskN
sudo dd if=BBB-eMMC-flasher-ubuntu-14.04-console-armhf-2014-08-13-2gb.img of=/dev/sdN bs=1m

Load onto BBB

Once the image has been copied to MicroSD card, unmount it and remove it from host computer. While the BBB is powered down, insert the card. Holding the boot button, press the power button. Wait until all the LEDs are lit and release all the boot button, a more detailed explanation can be found here.

Once all the LEDs are lit again, power down the board and remove the card. The BBB is ready to be used now. Connect a microUSB to the BBB and connect it to the host computer.

To connect to the BBB use the default password temppwd

ssh ubuntu@192.168.7.2

The following section will require an Internet connection. I have tried without success to share the OS X Internet connection over USB with the BBB. Instead a Ethernet cable was used.

3rd Party Software

There are several packages available from apt-get that will be used in the iLidar project. Some packages are not available from the apt-cache so they will be installed manually. Before installing any new packages update the current software.

sudo apt-get update

Then install the rest of the packages

sudo apt-get install libopencv-dev gcc make

PRU Software

The Programmable Realtime Unit (PRU) is used to interface with the camera. To get the software clone the github repo onto your path.

git clone https://github.com/beagleboard/am335x_pru_package.git

Make a directory for the headers that will be included in your c\c++ files.

sudo mkdir /usr/include/pruss

Now copy the headers into that folder.

sudo cp pru_sw/app_loader/include/*.h /usr/include/pruss/

Compile the libraries.

cd pru_sw/app_loader/interface; CROSS_COMPILE= make

Copy the libraries to /usr/lib.

sudo cp pru_sw/app_loader/lib/* /usr/lib/

Compile PASM

ldconfig
cd pru_sw/utils/pasm_source; source linuxbuild

Copy binaries to /usr/bin/

sudo cp pru_sw/util/pasm /usr/bin/

There is an included makefile that does some of the above include with the repo. I've opted to do it all manually here because it copies over the files in a way that I understand. Perhaps the makefile works just as above, but I am not sure.

I2C Library

This I2C library will be used for communication with the camera

It is a special library that wraps the SCCB protocol of the Omnivision cameras to I2C. The precompiled library did not work for me, but The non-compiled version did. I believe this is because it was compiled against a different kernel or with different settings.

Device Tree Compiler (DTC)

To enable certain modes on the BBB, the device tree must be manipulated. A newer version of the DTC needs to be installed than what is in the apt-cache. The following will install the newer version of the DTC.

wget -c https://raw.githubusercontent.com/RobertCNelson/tools/master/pkgs/dtc.sh; chmod +x dtc.sh; ./dtc.sh

Customize Settings

Most of the editing of files will be done on the BBB. Vim is my editor of choice so the .vimrc in my dotfiles will be copied over to both /home/ubuntu/ and /home/root/.

Macfuse will be used to mount the filesystem of the BBB and view or edit files from a host computer.

Disable HDMI framer

The iLidar will use pins on the P8 header that are used by the LCD and HDMI framer. To use these pins for the PRU, the HDMI framer must be unloaded at boot time. This is done by modifiying the /boot/uEnv.txt and adding

optargs=quiet capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

This must be done as root. As a general note, root is required for so much, might as well apply

sudo -i

to go into root interactive mode.