PInGo has been installed in a number of iPod Touches so it supports multiple participants at the same time. We also made sure to meet privacy requirements by not storing or sending any personal information.

The first screen capture below is the main menu which allows the user to select a survey depending on the time of day and whether they have completed it or not. The screen captures that follow demonstrate the variation in the survey’s question formats used. We were able to create an intuitive and dynamic interface, making use of the touch screen, shake gestures, show/hide animations, and question dependancies.

The technical cost to run this study is about $4/month with no hardware to purchase since we’re using a Cloud Computing Service. There was a chunk of time spent on researching the different technologies, setting up, developing the server side and client side, and designing and implementing the application’s graphics. The system has been pilot tested, tweaked, with the known bugs ironed out. If you are an academic or comercial researcher in need of a similar mobile app I would be interested in hearing your thoughts, feel free to contact me.

The technologies I used include: RackSpace for storing the data collected & Appcelerator Titanium for developing the iPhone OS app. I have a simple Webmachine RESTful API server (Erlang and Mochiweb-based) running in the cloud for collecting the data. The data can also be easily exported to a spreadsheet application like MS Excel or Google Spreadsheet, where it can be manipulated to your needs. The iPod Touch client app sends the data when it has a WiFi connection, but if there is no WiFi connection it just stores the data locally, allowing the user to continue entering new information. The technologies were chosen primarily due to their simple, speedy, and flexible development cycles, and secondly because of my familiarity with Erlang and Web standard technologies (HTML, Javascript, and CSS). The original mobile client app was developed using Titanium 0.8, but it was re-written from scratch in two days to the superior version 1.3. All the illustrations were done by Shi Shi, a fellow MADMUC graduate student.

I have learned much from this project and it is a great feeling to know that the system will be used for a worthy research cause. Thank you Susan Tupper for envisioning the project and Prof. Ralph Deters for giving me the opportunity to work on this project.

UPDATE: The following poster of the PInGo project was presented at the Canadian Arthritis Network 2010.

More Projects…

Once you create your cloud server on Rackspace, open the Web console.

Secure your server

Follow the instructions for Securing your cloud server. Also do the following:
$ visudo
/sudoers
# Allow sudo cmd access to new user
[new_user] ALL=(ALL) ALL

Setup your Firewall

Check your iptables current configurations

$ iptables -L

Open ports

$ sudo /sbin/iptables -I RH-Firewall-1-INPUT 1 -p tcp –dport http -j ACCEPT
$ sudo /sbin/iptables -I RH-Firewall-1-INPUT 1 -p tcp –dport https -j ACCEPT
$ sudo /sbin/iptables -I RH-Firewall-1-INPUT 1 -p tcp –dport ssh -j ACCEPT
$ sudo /sbin/iptables -I RH-Firewall-1-INPUT 1 -p tcp –dport 8000 -j ACCEPT
$ sudo /sbin/services iptables save

Check your changes

$ iptables -L

Logout and close Web console.

Install Erlang

Open a terminal (or Putty on Windows) and SSH as [new_user]
$ ssh [new_user]@[your cloud server ip]
$ sudo yum install gcc glibc-devel make ncurses-devel openssl-devel
$ wget http://erlang.org/download/otp_src_R13B04.tar.gz
$ tar zxvf otp_src_R13B04.tar.gz
$ cd otp_src_R13B04
$ ./configure && make && sudo make install

Install Mercurial via RPM

$ yum install python-devel rpm-buildtp://mercurial.selenic.com/release/mercurial-1.4.1.tar.gz
$ wget http://mercurial.selenic.com/release/mercurial-1.4.1.tar.gz
$ cp mercurial-1.4.1.tar.gz mercurial-1.4.1.tar.gz.orig
$ tar zxvf mercurial-1.4.1.tar.gz
$ cd mercurial-1.4.1/
$ cp contrib/mercurial.spec contrib/mercurial.spec.orig
$ sed -i -e’s/snapshot/1\.4\.1/’ contrib/mercurial.spec
$ sed -i -e’s/, docutils >= 0.5//’ contrib/mercurial.spec
$ cd ../
$ tar cvf – mercurial-1.4.1 | gzip > mercurial-1.4.1.tar.gz$ rpmbuild -tb mercurial-1.4.1.tar.gz
$ rpm -Uvh /usr/src/redhat/RPMS/i386/mercurial-1.4.1-0.x86_64.rpm
$ hg –version

Install Webmachine

$ hg clone http://bitbucket.org/basho/webmachine/
$ cp -r webmachine /home/projects
$ cd /home/projects/webmachine
$ make
$ /scripts/new_webmachine.sh ediaryAPI ..
$ cd ../e*
$ make

Run Webmachine

$ ./start.sh

Visit http://[ip]:[port]

References

https://wiki.basho.com/display/RIAK/Installing+Erlang
http://cloudservers.rackspacecloud.com/index.php/Firewalls
http://cloudservers.rackspacecloud.com/index.php/Basic_Cloud_Server_Security
http://cloudservers.rackspacecloud.com/index.php/Common_iptables_rules_for_CentOS_5.3

The first set goes over the Erlang data storage modules ETS, DETS, and Mnesia. These modules are part of the Erlang library and are extremely powerful and flexible for storing data. The second set briefly outlines Mochiweb and Webmachine. Mochiweb can be used on its own as a lightweight HTTP server. Webmachine is built on top of Mochiweb providing a Web service gateway interface, ideal for building an API server.

Erlang Data Storage Modules

Webmachine