Magic Cauldron
An interactive installation to help children learn about animals and their role in the urban natural landscape.
Customer:
G.Eco – Associazione Culturale
Challenge:
Create a NFC Tag based system capable of reading the tags in the correct sequence and open the cauldron door to release a Diploma. Lights and sounds were part of the requirements.
Year:
2017
The Magic generation
The younger generations grew up with HP movies and books by J.K. Rowling, turning magic into something cool. G.Eco is an association that promotes knowledge and understanding of nature. They are invited to many events and every time they create a whole narrative to let the kids discover and learn the many aspects of urban ecosystems and the animals that usually surround us.
This time they created a story about a magic potion, to be concocted finding the right ingredients out of a number of clues laid out in a series of steps. Only the right sequence with the right ingredients would have granted the wannabe magician the title.
The cauldron was therefore the last step in the quest and it had to be somehow “magic”. the design was a team effort, discussing with G.Eco team the behaviour, while a papier mache artist was creating the cauldron. Each ingredient was inside a small fabric pouch, hiding inside an NFC Tag. A special gold gecko pawn was the base that tested each ingredient, while the cauldron had some cotton fluff with a ring of LEDs to add some smoky effect. The whole thing was able to make sounds and noises as if it was possessed by an entity, accepting or refusing every ingredient.
If the sequence was right, other sounds effect and lights would confirm the achievement and the door on the front would slowly open to reveal the rolled parchment with the title of Wizard.
Digital Fabrication
The making of my part of the project – basically everything except the papier mache cauldron – required all the basic techniques of digital fabrication and prototyping. As a maker, I am familiar with all of them and therefore I just put at work my skills.
The etching of the gecko pawn on an acrylic disk was done with my little CNC router, then I used some gold paint to make it visible. A 3D printed round shape with a risen border made the other half of the disk, protecting the Smart LEDs ring, connected with just three wires to an Arduino Nano board.
The same Arduino Nano was driving another set of Smart LEDs: that was the strip going around the whole internal ring of the cauldron and covered with cotton wool to simulate some magic smoke.
An MP3 board and two amplified small speakers were hidden in two cavities and provided the audio for the whole setup. A bubbling noise was almost constantly played when the cauldron was waiting for some tags to be put on the gecko pawn.
A servo motor was connected to the door of the cauldron with a 3D printed lever; the servo was activated and the door opened only when the sequence of NFC tags was completed correctly.
A special pouch had a tag that was defined as the master reset; putting that one on the pawn closed the door – if open – and restarted the whole sequence. The bubblying sound was also used by the team to know that everything was working properly and that the cauldron was waiting for the first pouch.
The whole system was powered by a 12 volts power supply and an internal power regulator, hacked from a car cigarette lighter to USB, fed the 5V electronics in a reliable way.