Sounds for Martin Janíček's WaterMirror in Troja (Praha, CZ)
Martin Janíček asked in October 2024 to make a device that plays the sound of water on his public sculpture in the park around the castle in Troja 7. The experiment lasted some months, extending an ESP32 with a sd-card reader, a small amplifier, bone conductor, a day/night interruptor, a voltage controller and solar panel. The coding was done in the Arduino IDE, and simply loops the soundfiles on the sd-card. The transducer is attached to the metal sculpture and produces the water sound. In the end the solar solution was skipped and a 3.7V net adapter was used instead. We liked the idea of the water volume being controlled by the amount of sunlight. The sculpture would be silent in the night, on darker days and parts of winter, but Martin preferred the audience to hear it any moment they would walk in the park.
The choice of the artist always wins of course, but I am mentioning it here as part of the experiments we did: starting with a rpi 3B, a pico and zero pi, with soundcards. But these were too power hungry still. The equipment includes:
- breadboard with ESP-WROOM-32
- max 98357A I2S mono amp Vin=2.5-5.5V in
- HW-125 SD Card Adapter
- BH1750 Light sensor
- Dayton Audio BCT-3 44 x 32mm Bone Conducting Transducer
- Photoswitch TDL-2025-CDS daytime
- Seeed Studio LIPO rider Pro
- Solar Power Manager Wave Rider
- LIPO 3.7V 20000mAh
- several types of solar panels
