The e-cicadas are small electronic devices that generate sound through acoustic means. They are built from repurposed LED light keychains that contain a tiny solar panel and a rechargeable battery. The LEDs have been removed and a small microcontroller added. The microcontroller controls a small motor or a similar device that is used to generate sound by hitting, rubbing a surface, vibrating or moving.
They generate sound for a short duration when sufficient light hits them.
The e-cicadas can be placed anywhere and use any surface to generate sound. By placing several of them, a small orchestra of e-cicadas is created.