Voce di Blenio

The digital archive contains all the publications of the 50 years of the monthly journal titled "Voce di Blenio". That means 600 editions, resulting in 8'701 pages.

The goal was to build a web app capable of searching any terms among all the pages and showing only the one containing those terms in the specific selected period, as well as scrolling through the list of all the editions organized by time.

Each page was a single PDF file, the oldest coming from the original scanned pages with an OCR (Optical Character Recognition) program to get the text content digitally. The newest one was exported from the editing software used to write them. The overall space taken by the files was about 9GB. So, quite a daunting task!

The PDF web viewer chosen has been PDFjs, free and open source. The web app running locally has been written in PHP, JS, and AJAX.

As you can imagine, directly searching via the web in 9GB of PDF files, even if locally, is a very demanding task and takes a lot of time, so a better method had to be found. The solution consisted of automatically scanning all the folders containing the PDF at the start of the local server and updating a single JSON file containing each PDF's text and its path for later linking.

In this way, the searching task was performed on the lightweight text JSON file, and the HTML page with the results just contained the link to the corresponding PDF file that eventually would open with PDFjs once the user clicked on it.

The web app was snappy and quick, even on the old PC used during the exhibition (also a display object part of the storytelling). It required a change from the Windows XP OS on the original mechanical HDD to a much faster SSD disk with a lightweight Debian distro to run the server for the web app.

The experience continued to be more physical once the visitor printed the selected page with the dedicated button in the web app on an A3 printer connected to the PC to keep a copy of it for them to bring home.

The playback of some old interviews about the journal has been integrated into an old radio object of interest in the exhibition. This old AM/FM radio has been upgraded to play digital audio files from an SD card using the headphones or the added integrated speaker. Still, it uses all the knobs and the original interface.

Everything is based on a Teensy 3.2 board with its original audio shield. The analog and digital pins read the interface's potentiometers and selectors and control the tuner LED and its analog dial (PWM pin). I designed and built a PCB board to simplify all the wire connections and cut it on a small CNC milling machine.

The old mechanical variable capacitor responsible for the frequency selection of the tuner has been removed and retrofitted with a potentiometer mounted on a 3D-printed reduction gear system for the Teensy board to read the current tuner position still.

The simulated tuner works conceptually as any analog radio tuner, but it's fundamentally different; the powerful Teensy board plays the audio WAV files once the selected tuner frequency corresponds to the name of a file on the SD card, for example, at 98 MHz it will play the file 98.wav (if present obviously). Suppose there is no corresponding audio file on the SD card at the currently selected frequency. In that case, the Teensy board will play internally generated pink noise to simulate the radio out of tune.

When the tuner gets closer to the frequency of an audio file (originally a radio station), the volume of the pink noise diminishes, and the audio files increases. Moving past the audio file frequency, the reproduced sound will fade to the pink noise.

Internally the Teensy board also changes the sound regulating the volume, bass, treble, and right/left balance according to the position of the corresponding knobs on the radio.

So, the radio still works as it originally did, feeling precisely genuine.

One of the rooms has been dedicated to playing old videos about the valley. Because of the limited space, using a dedicated table or stand with the interface to select and play the videos was not desirable.

So the control interface has been integrated and projected directly on the screen; three conductive surfaces have been mounted behind the screen at the right height to match the projected buttons to move up and down in the list of the videos and the play button as well.

The three aluminum plates had been connected to the touch pins of a Teensy board used to communicate (as HID interface), with the Processing sketch responsible for the videos' playback and projection.

Once a video is selected, the interface disappears, leaving the entire screen for the video playback. It will appear again once the video end and the main list of videos appears again.