Debugging Audio Installation Piece: Activity

In addition to the video piece, I decided to include audio in the exhibition in the form of a morse code version based on the letter that formally triggered Article 50. Unlike the video, I did not want it to be a continuous loop instead I wanted it to be spectator triggered. The trigger device would be a Morse Key that would start the morse code transmission.

Similar to the video piece a Raspberry Pi micro computer was selected as the brain of the piece. In this case, I needed to have an interface module to detect the Morse Key being depressed.

After conducting some research on the internet I found a design for the hardware and an associate code segment using the Pi’s GPIO module.

I built up the module and ran a few tests which showed that the breadboard module was fragile and it did not trigger the audio consistently. 

Raspberry Pi – Using GPIO Breadboard
Source code to capture Key Press

Based on my own production values and with a weather eye to future installations where the piece might be left unattended for long periods of time I decided to search for a more robust solution.

A second internet search identified a company sf-innovations who make interface modules for the Raspberry Pi used under the banner Custard Pi. I order the 8 digital I/O module. This module mounts directly on the Raspberry Pi resulting in a more robust installation.

The following day the module arrived so time to install write a new script and test the new rig. The tests resulted in a much more stable solution where the Morse Key successfully triggered the test audio file.

Raspberry Pi with Custard Pi Board
Revised script using Custard Pi

The next steps are to procure some authentic 2 core cable to connect the Morse Key to the Raspberry Pi. Source a box to install the microcomputer, speaker, power supplies, and adapter cables.

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