Introduction: Ember (Interactive Virtual Campfire)

Ember is an interactive installation, which explores community through a campfire-like circle of wooden seats that generate music from a visitor’s presence. Each seat in the circle is an instrument, which adds a note to a melody. This melody is a composition formed from the presence of visitors. In this way Ember establishes a conversation of social contact, time, and nature.

Ember places visitors in the ‘familiar’ arrangement of a campfire in which one is never alone but surrounded by the notes of previous visitors. It is a community of the past present and future. Ember is a window into the song of the city, provoking interaction between visitors and a space of reflection on the daily movements of urban life.

As a visitor approaches the piece they see a round deck made out of narrow slats of wood and a circle of what appears to be logs. On closer inspection the visitor can see that the logs are finely formed and gracefully rounded wooden seats. As the visitor sits on a seat, it emanates a bright glow beneath it and a soft marimba-like melody plays. Each seat weaves the song and storyline of the presence of all previous visitors.

Each note is unique to someone who occupied this log in the past. The notes are created based on how long a visitor has been with the piece, when the visitor leaves, a note will be added to the melody, only to be heard by future visitors. While two or more visitors occupy logs, the historic melodies combine creating a richer, more intricate song. This is a gathering around a campfire, a melodic observation of entanglement of presence, now, and past.

Ember provides recollection amidst a place of transition. Public places often seem distant and impersonal, used only as a causeway, a place of temporary inhabitance. Ember provides the contrast of an ever updating historic melody.

"Ember" is a project created for the Market Street Prototyping Festival By: Jason Rasmussen, P. Gilbert Schmitt, Oris Buckner, Zhijie Chang, Sofia Villena.

Thank You: Exploratorium, Yerba Buena Center for the Arts, Gray Area, Ben McChesney, Adam Esposito, Steve Gennrich, Adam Green, Marin Arborists, Catey Ritchie, City of San Francisco.

Step 1: Materials

5, redwood logs around 1.5 feet in diameter and around 1 foot 8 inches long.

1, Raspberry Pi or computer

1, Arduino Uno

5, .5 Inch Force Resistors,

2, speakers, we used 6" car speakers

1, Kinter 12V 2 CH Mini Digital Audio Power Amplifier

power strip/s which can handle at least 8 power supplies

5, 5V power supplies for Neo Pixels

1, 9V power supply for Pi

1, 12V power supply for Amp

5, meters Neo Pixel LED's

10, rubber stoppers, at least 1 Inch in diameter

lots of signal wire, around 60ft

20 steel springs, we used 125lb resistance but we recommend around 80lb.

8 2'X4' Joists

21 2'X6' Decking

Step 2: Design

We used Illustrator, Photoshop, and Maya, to make mockups and renderings to visualize the project. Then we constructed a Balsa wood scale model and actually built the mini seats around buttons so we could test our program. We developed the code in Open Frameworks on CodeBlocks and Xcode. We also worked with Yerba Buena Center For the Arts and the Exploratorium to gather feedback on the design. We did most of the manufacturing at Tech Shop and The Exploratorium.

Step 3: Fabrication


The code for the computer or the Pi can be found here:

Though it worked on the Raspberry Pi we had some trouble on the B+ with the serial connection and we had to use Minicom to initialize the connection.

for information on setting up the Neo Pixels:


We worked with Marin Arborists who graciously donated the Redwood logs and cut them to size as well as transported them. We then used an Angle grinder with a rough grit disk to round out the edges, then a softer grit and eventually hand sand them to a smooth finish. We then used Danish oil to protect them. For the decking we lined all the boards up marked the center point then tapped a nail in. To the nail we tied a 5foot string with a pencil at the end to mark the circle. Following that line with a band saw and a jig saw we cut the circular deck.

The 16 edge Joists were cut with a chop saw at 22.5 degrees with a length of 1.95ft

The main support joists we eyeballed and marked before cutting.

We got two small plastic containers to hold the electronic components and drilled holes in them and the bottom of the joists to rout the wires from a central point to each log.

We also laser cut a plaque with 5 equidistant lines on it marking the location of the 5 logs on the deck 1.5ft in from the edge.

after marking the circumference of the logs on the deck we then removed the logs and marked 4 holes for the screws to come through. This had to be eyeballed as the holes need to be close to the center of each board for maximum support. after marking and drilling these holes we then placed the logs back on the deck and marked the bottom of the logs through the holes. Finally we flipped sections of the deck onto the logs and bolted them down with the spring and 3 washers. The sections were then flipped back into place and the Neo Pixels and sensors were routed under the logs before the deck was screwed into the joists.

The sensors were sandwiched between two rubber stoppers and placed under the log. They took some fine tuning with shims.

The Manufacturing and development took about a month not including early concepts and experimentation.

Step 4: Installation

For the final installation we disassembled the piece and hauled all the materials in an SUV. It took 3 trips to the site and a bit more than a full day to install with the help of over 8 people, so we recommend many hands as the logs are very heavy. See previous step for install instructions.

Step 5: Interaction

Once completed, the sounds successfully played and the lights too, however for future iterations we think a larger variety of sounds, unique for each seat and with more octaves would yield even more communal participation. We experienced Jam sessions, rap battles, and even a puppet show on Ember. We found that Ember was not just an art piece but an ice breaker. We ended up turning the volume down a bit because people wanted to talk and communicate along side Ember's melody.