#A library to connect arduinoYun to nodeJS via a socket.io protocol# The library is composed of a Python script that make use of socketIO-client to connect to a socket.io sever and an Arduino Library to communicate to the Python script.

The following guide and library is based on the work of Tobias Oberstein Getting started with Arduino Yun and Autobahn

You will need an arduino YUN properly configured to connected to the Internet

To configure the YUN for 802.x network like eduroam follow this guide http://forum.arduino.cc/index.php?topic=197267.0 Thanks bitfrosting

##how to install the library?##

####Connect to the Arduino Yun via ssh####

ssh root@myYun.local

####Update the packages####

opkg update

####Install a sftp server ####

We want to install openssh-sftp-server so that we can connect to the yun via our favorite ftp software (fliezilla, cyberduck, etc)

opkg install openssh-sftp-server

if it doesn't find the package you have tu update the repository list, open the opkg configuration file with

vi /etc/opkg.conf

and change the first line to

src/gz barrier_breaker http://download.linino.org/dogstick/all-in-one/latest/packages/

your opkg.conf now should look like this

src/gz barrier_breaker http://download.linino.org/dogstick/all-in-one/latest/package
dest root /
dest ram /tmp
lists_dir ext /var/opkg-lists
option overlay_root /overlay
option check_signature

now you can install openssh-sftp-server

####More packages ####

let's install other packages we will need

opkg install bzip2
opkg install unzip
opkg install tar
opkg install wget
opkg install fdisk
opkg install e2fsprogs
opkg install openssh-sftp-server
opkg install distribute
opkg install pyopenssl
opkg install python-openssl
opkg install python-crypto
opkg install python-bzip2
opkg install python-sqlite3
opkg install python-ncurses		

This might take some time, but the packages are installed into the / root filesystem and will be permanently available from now on.

####Format the SD card####

The / filesystem on the Yun only has 8MB space in total (the other 8MB of the total 16MB Flash are used for system recovery) The free space on / isn't enough for the software we will use. And we also want to have space for local data storage. Hence we will create a new filesystem on a micro SD card which we can use for both programs and data.

Make sure you have your SD card inserted. Then, create a new ext4 filesystem on the SD card (WARNING: this will erase all data on that card without any further questions!):

umount -f /mnt/sda1
mkfs.ext4 -O ^has_journal,extent /dev/sda1
mkdir /opt

To manually mount the filesystem you could do

	mount -t ext4 /dev/sda1 /opt

A better way however is to have the filesystem automatically mounted at startup of the Yun. For that, add the following new entry to the filesystems configuration in the file /etc/config/fstab:

config mount
option target       /opt
option device       /dev/sda1
option fstype       ext4
option options      rw,async,noatime
option enabled      1
option enabled_fsck 1

To check size and free space

df -h

####Creating a Python Virtualenv#### Virtualenv is a widely used Python tool that allows to create complete Python environments in different locations and with different setups. We will use Virtualenv to create a Python enviroment on our SD card under /opt/python.

/usr/bin/easy_install virtualenv

Now create a new Python environment on /opt/python (residing on our SD card):

/usr/bin/virtualenv --system-site-packages /opt/python

After that, you should have a new Python here:

root@miniverse:~# /opt/python/bin/python
Python 2.7.3 (default, Aug  8 2013, 22:36:42)
[GCC 4.6.4 20121210 (prerelease)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

From now on, you have two sets of Python binaries, the system Python:

root@Arduino:~# which python
/usr/bin/python
root@Arduino:~# which easy_install
/usr/bin/easy_install

Make sure you use the full path to the Python (or easy_install) you want to use:

/opt/python/bin/python
/opt/python/bin/easy_install

or activate the virtualenv by doing

root@Arduino:~# source /opt/python/bin/activate
(python)root@Arduino:~# which python
/opt/python/bin/python
(python)root@Arduino:~# which easy_install
/opt/python/bin/easy_install

This activation will simply modify your shell environment appropriately, so it isn't anything persisting. Personally, I usually don't bother with virtualenv environment activation, but simply use fully qualified paths.

####Install socketIO-client #### The python library we are going to use is based on socketIO-client. once we have activated our vistual evironment with:

source /opt/python/bin/activate

we can use pip to install the package, it will automatically install all the required dependencies

pip install -U socketIO-client
pip install simplejson

Spacebrew library for arduino is using a python websocket library as well. Somehow, even if just created a python visrtual environment, the websocket library installed in the main python library at /usr/lib/python2.7/websocket' conflicts with the one that we need installed in our /opt/python/lib/python2.7/site-packages`.

My temporary solution is to remove the websocket folder from the root python:

rm -rf /usr/lib/python2.7/websocket/		

####Install the python script on the YUN#### Start by downloading this repository. use your favourite ftp software to open a connection with your board

protocol: sftp
address: [yourArduinoYUNName].local
user:root
psw:[yourArduinoYUNPassword]

Create a folder called myScripts in /opt/.

you might use this folder in the future for other python scripts

copy the entire folder /linino files/SocketIOYunClient from the repository to the folder /opt/myScripts/

you will need to make /opt/myScripts/SocketIOYunClient/socketIOClient.sh executable.

chmod +x /opt/myScripts/SocketIOYunClient/socketIOClient.sh

####Finally install the Arduino Library#### To program the arduino yun the beta version of the IDE is needed. ThisOne usually creates a new sketch folder. Copy the repository to `[your Arduino-Beta sketch folder]/libraries/ Restart your IDE and you are good to go!