What is gumstix?

• Gumstix is a line of single-board computers that come in a tiny (gumstick-sized) package. Several different versions of the board are powered by XScale PXA processors and come with varying speed, onboard memory and peripherals.
• Additional features can be added to all motherboards with plug-in expansion cards with features like wireless networking, audio in/out, robotic motors and sensors, etc.
• Gumstix software and operating system is a full-blown Linux environment that can run a large range of applications.

What is it good for?

	Robotic fish at the London Aquarium: Biologically inspired by the common carp, the robotic, gumstix-driven fish could avoid objects and swim around a specially designed tank entirely of their own accord.
	Flying web server: UltraSwarm, a flock of wirelessly networked autonomous miniature helicopters flying like a flock of birds while computing like a wireless cluster computer and serving data to web pages.
	Ebook reader: Since the XScale chip on the Gumstix is largely identical to those found on PDAs two or three years ago, the Gumstix is easily usable for portable electronics. Apparently, the guys at E-Ink use a Gumstix board to power their e-paper displays.
	Robot that vacuums and serves web pages: Roomba vacuum cleaner controlled by gumstix connex board, a PhD thesis project at MIT.

Gumstix Flavors

• Verdex is the most advanced and most expensive gumstix motherboard
  (up to 128Mb RAM, 32Mb Flash, 600Mhz processor @ $169), followed by Connex and Basix.
• Gumstix.com also sells gumstix “computers”, which are essentially motherboards that come with an enclosure. Netstix computer is based on the Connex motherboard and Waysmall is Basix on the inside.

Hardware used in this class:

• Verdex XL6P motherboard, console LCD16-vx expansion board, Samsung 4.3″ LCD, serial null-modem cable, USB cable
• Hardware is basically equivalent to the set of peripherals sold with
  LCD pack by gumstix.com for $412, minus the netmicroSD expansion board

Connecting to Gumstix via Serial:

• Open a serial connection with the following parameters
  (On Windows PC, you can connect using Hyperterm):
  
  Bits per second: 115200bps
  
  Data bits: 8
  Parity: none
  Flow control: none
• Snap Verdex XL6P and console LCD boards together
• Connect serial null-modem cable to the middle serial (round) connector on console LCD board
• Connect the other end of the serial cable to PC, perhaps through USB-to-serial adapter such
  as Keyspan 19HS.
• Plug in the USB cable to console LCD board on one end and USB port on PC the other.
• Gumstix should start booting with output to the serial terminal!

Linux Setup:

• Install a Linux environment. I used Ubuntu Linux distribution running on VMWare virtual machine within Windows. This is a class topic all by itself!
• Install and setup minicom terminal for serial communication.
  apt-get install minicom
  minicom -s

  Change minicom settings to match the following:

  

• Install drivers for Keyspan USB-to-serial adapter. I followed the directions on
  this page.
  The driver installer file that worked for me was
  keyspan-ubuntu-2.6.22.52.deb.
  To run debian installer for this package, use the command:
  dpkg -i keyspan-ubuntu-2.6.22.52.deb
• Test the Keyspan adapter.
  mknod /dev/ttyUSB0 c 188 0
• Plug-in the adapter to USB port, then start minicom:
  minicom -o

  Hopefully, you can now talk to gumstix via serial connection from Linux.

Cross-compiling with Buildroot:
This will allow us to compile programs that can run on gumstix within the PC Linux environment.

• Install Buildroot using Subversion (SVN):
  
  enter your home directory:
  cd ~/
  create buildroot directory:
  mkdir gumstix-buildroot
  run svn command:
  svn co http://svn.Gumstix.com/Gumstix-buildroot/trunk gumstix-buildroot
  enter gumstix buildroot directory and configure:
  cd gumstix-buildroot
  make defconfig
  rm .config
  run make command entering 12(verdex) and speed 4(600MHz) when prompted:
  make

This will take quite a while..

Cross-compiling with Open Embedded:
The firmware that came with the gumstix board you bought is probably older than the one
that Buildroot is now set up for, so we’ll have to compile the new gumstix filesystem.
To be incompleted…

Flashing the gumstix file system:
Burn the filesystem compiled in the previous step it to the gumstix board.

• Open a serial connection with kermit (minicom didn’t work for this step), load settings and connect:
  
  kermit -l /dev/ttyUSB0
  C-Kermit> take ~/gumstix-oe/extras/kermit-setup
  C-Kermit> connect
• Plug-in gumstix USB connection to power up the board and interrupt the boot process in terminal (by hitting any key)
  to get into bootloader.
• Type the following commands very carefully or you may brick your gumstix!!
  
  GUM>loadb a2000000

  Press ‘control’ and ‘\’ and then ‘c’

  cd gumstix-oe/tmp/deploy/uclibc/images/gumstix-custom-verdex/
  send Angstrom-myImage-uclibc-ipk-2007.9-test-20080218-gumstix-custom-verdex.rootfs.jffs2
• Erase the current filesystem:
  GUM> protect on 1:0-1
  GUM> erase all
• Write the new filesystem to flash:
  GUM> cp.b a2000000 40000 ${filesize}
• Load the new kernel:
  
  GUM> loadb a2000000

  C-Kermit> send uImage-2.6.21-r1-gumstix-custom-verdex.bin
  C-Kermit> connect
  GUM> katinstall 100000
  GUM> katload 100000
  GUM> bootm

Hello Gumstix!
Finally, we can now compile a custom program that will be able to run on the gumstix board.

• Grab the sample hello.c and Makefile files, put them in hello-world directory and compile:
enter your home directory:
cd ~/
create hello-world directory:
mkdir hello-world
enter hello-world directory:
cd hello-world
run make command:
make

The executable ‘hello’ should now be created in this directory.

• Open serial connection to gumstix using minicom:
  minicom -o
• Power up the gumstix with USB cable and watch for boot process output in the terminal window, then login with ‘root’ and password ‘gumstix’ at the prompt.
• Upload ‘hello’ executable to gumstix via minicom:

  Press ‘control’ and ‘c’ keys to get to minicom prompts. Then press ’s’ to send file.
  Select zmodem as upload protocol by pressing ‘enter’.

  Press ‘enter’ again to bring up file upload prompt for current directory. Type the
  following filepath and press ‘enter’:

  gumstix/hello-world/hello

  If successful, you should now get a transfer complete prompt like this:

  

• Run the program:
type the following command (’./’ means run in current directory):
./hello

the program should return:
hello gumstix!