ArduinoYunOpenWrt101

Arduino Yun and OpenWRT 101

This tutorial covers a little introduction to video recording with on the awesome Arduino Yun board!

I assume that the reader has a pc or a mac (named Bob) and an Arduino Yun, named Arduino. Moreover, I suppose the reader is quite familiar with the computer in general and know a little bit of shell/linux commands. In particular I in my case Bob is a mac os/x and, and everything is starting with an iTerm2 session where everything begin with a dollar sign ($)..

Some tricks

What I'm using (but not strictly needed if not specified) is iTerm2 as shell terminal on Bob with Oh-My-Zsh as shell, and Sublime Text 2 as a free text/code editor (that is a nice cross-platform generic text editor).

Let's become confident with the board

arduino.local does not always resole, so safely to use the ip number (192.168.240.1, for initial configuration) then the host name.

SSH from Bob to Arduino

To log into the yun via ssh (from Bob shell):

	$ ssh root@192.168.1.13

Now you're logged in the Arduino Yun linux board. We are inside an embedded linux machine, in particular a child of OpenWrt. For briefness I will differentiate what is happening inside the iTerm session in Bob with $ and what is happening inside the yun shell accessed via ssh with ~.

Know where we are

See which distribution, kernel version, etc:

    ~ cat /proc/version
    Linux version 3.8.3 (federico@smilzo) (gcc version 4.6.4 20121210 (prerelease) (Linaro GCC 4.6-2012.12) ) #8 Mon Aug 19 16:22:39 CEST 2013

See devices already mounted:

    mount

After each installed package, to see free space on the hard disk:

    ~ df -h
    Filesystem                Size      Used Available Use% Mounted on
    rootfs                    7.5M      4.9M      2.6M  66% /
    /dev/root                 7.0M      7.0M         0 100% /rom
    tmpfs                    29.9M    372.0K     29.5M   1% /tmp
    tmpfs                   512.0K         0    512.0K   0% /dev
    /dev/mtdblock3            7.5M      4.9M      2.6M  66% /overlay
    overlayfs:/overlay        7.5M      4.9M      2.6M  66% /
    /dev/sda1                 7.4G    848.0K      7.4G   0% /mnt/sda1

Basic networking

Find out the ip of Arduino Yun

Upload a sketch that via Bridge library (for instance Process class) run the netstat command and print out the result on Serial Monitor.

Run a python server from Arduino

To run a python server

    ~ python -m SimpleHTTPServer

To grab a file from Bob via the brand new Http server just open a browser and ...

See open port on Arduino

See if python server is running (from Bob):

    $ nmap 192.168.1.13
    
    Starting Nmap 6.40 ( http://nmap.org ) at 2014-04-30 13:03 CEST
    Nmap scan report for 192.168.1.13
    Host is up (0.19s latency).
    Not shown: 995 closed ports
    PORT     STATE SERVICE
    22/tcp   open  ssh
    53/tcp   open  domain
    80/tcp   open  http
    443/tcp  open  https
    8000/tcp open  http-alt
    
    Nmap done: 1 IP address (1 host up) scanned in 39.77 seconds