Nicholas Bryan – music, computing and design researcher at Standford University has made an app for iPhone that simply transform your old dj equipment into a brand new and full option digital table. For the complete setup you need two iPhones tuned with Nicholas Bryan’s app and an apple laptop and you are ready to rock. Mopho DJ uses iPhone’s’ accelerometer and gyroscope to detect, emulate and recreate DJ’s scratching motion. The data collected is wirelessly transmitted to the DJ’s computer to manipulate its audio playback.
For hardware, a single mobile phone, piece of sticky rubber and plexiglass disc were used for each wirelessly enabled record. Fourth generation iPod Touch or iPhone 4 devices were found to work well. Both devices include a three-axis accelerometer and three-axis gyroscope with a maximum sample rate of 100 Hz as well as a multi-touch display and wireless networking capabilities. The iPod Touch is physically thinner than the iPhone 4 and found to be slightly preferable. In order to attach the device to a vinyl record, sticky rubber is placed in between the record and mobile device. Commercially available rubber mats (used to hold mobile phones against a car dashboard) were used and found to be suffciently sticky. Various plexiglass discs were used in place of a vinyl record. By varying the weight and size of record, a performer can customize the drag or friction between the record and slipmat to suit their needs.
Nicholas Bryan will present Mopho DJ at the New Interfaces for Musical Expression conference in Norway at the end of May.