Chromatic Composer- Making the drawing

After the achievement of listening a drawing, we started working on the “making the drawing” side of the project.

This time we started with the part of hearing, analysing and mapping the characteristics of sound. In the beginning we were going to use other program to analyse the sound (Pd) and then transfer the values to the machine. But since Grbl can work directly on Processing and Processing libraries seemed to work easier, we adopted Minim library for sound analyse purposes.

The variables that we got out of live input sound are amplitude and frequency. The mapping of the frequency follows the logic of the reading part of the machine (Colours) and the changes in amplitude direct the motion. In the beginning, the drawing prototypes were virtual and even when we mapped the variables to straight lines, we discovered issues in the drawing due to speed of reading, multi frequency reading and errors in coding. After solving some problems we decided to wait till the machine was functional to try the code again.

The machine was built as a simple x, y plotter, and even with some details we started drawing with it. By surprise, the details in accuracy due to off-axis movement of the carriage or pivoting in pens, showed up as a style of scribbling/drawing, and after meditating long time, we decided to keep the inaccuracy as part of the machine.

For activating the pen colours we used a second Arduino board to control 3 servos rotating according to the sound. For low frequencies the BLUE colour must be activated, for middle frequencies the GREEN, and for high frequencies the RED coloured pen.

The first attempt drew a mix of lines responding to a simple code of change in xy position.


The second, was a try to draw rectangles which position and size responded to sound change.


The third was a triangle version


After experimenting with linear motion, we thought in the inclusion of curves to expand the visual communication of our drawings, as well as a definition of style. Moreover, curves help in boosting the imagination of what we see.

The following two drawings correspond to two different music styles employing arc motion based on the same sound variables.



As we thought before, the idea of including arcs in the drawing, made it visually more interesting.


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