On the occasion of the Estação Maritaca (Maritaca Station) event at SESC Pompéia in October 2018, I created two gadgets and I gave a workshop where the children built a "musical toy". The idea behind the event, designed by the artist Mariana Piza, was to give children experiences from a radio station.
The Maritronic Turntable is a gadget that mixes the possibilities of a mixer, a turntable and a music selector, all in a box with transparent top so that the children can see and be curious about the components that allow their operation.
Kids can scratch using a disc and crossfader, choose and combine loops of songs, change the volume and the speed with which these loops are played.
The design of the box, the rotating disk and the acrylic cover are the artist and set designer Julio Dojcsar.
The Vitrola Maritrônica was arranged in a kind of igloo (scenography by Marisa Bentivegna) in which four children could interact with the traquitana at the same time.
In superficial terms the Maritronic Turntable works as follows. Two prototyping boards, Arduino Duo and Teensy Board, digitize and process data from faders and rotary knobs (encoders) as well as from the spinning disc. A single board computer Raspberry Pi running the SuperCollider with an expecially written program for the device. A special sound card for the Raspberry Pi turns the signals generated by SuperCollider into real sound.
The Maritaca Recorder is an object with which the children listen to tips for them to record stories and make interviews with each other. Through a simple interface they operate and record without needing help of the adults.
The recordings are stored and made available for use in the Maritaca application.
Inside the metal case is a Teensy development board attached to a specific audio card, to which the microphone and earphones are connected. The recordings are stored in an SD card.
Traquitronic - Musical Toy Workshop
In this workshop aimed at children from the age of eight, we built simple electronic instruments together, with simple elements, without soldering or complicated circuits. They can touch them with gestures, controlling the light, and buttons, and still combine the instruments of each other. At the end participants can bring their instruments home.
- learning basic principles of electrics, electronic and audio, from practical activity.
- Construction of an electronic instrument that can be taken by the participants.
Based on an integrated circuit, we build on a prototyping board a simple circuit that generates electrical pulses at audible frequencies, which we hear through small speakers. Frequencies can be modulated using light sensors and rotary knobs. In the end, as experimentation, the instruments can be combined together, generating cross modulation and thus, more complex sounds.