PD + RoR

Mobile music using RoR web server, Android and PD

App Screenshot

It is just a proof of concept project for my research about mobile music with Android and web servers. Technologies used: Ruby on Rails, Passenger, JSON, Android, and Pure Data.

In this project the user can play notes using a keyboard on mobile phone touchscreen and share notes played through a web server. The user chose a username and the synthesizer, start playing, and can also hear other users notes at the same time.

I’ve created a webserver application to receive Note On and Note Off informations from users and respond to requests. The application was developed with Ruby on Rails and deployed with Passenger.

The Android app has a little “keyboard” disposed to be played by the user, and each Note On and Note Off (with the username) is sent to web server. JSON format used:


The app requests new notes from web server continuously, so the notes from the other users are played on other user’s devices, indeed. I’ve used a Pure Data polyphonic patch embedded into the Android app to play the notes with four synthesis presets.

After some tests it started sounding funny… hearing asynchronous notes played through the internet with friends is not so bad. = )