ChoreoPrint

Conceptual Design

ChoreoPrint began as a tool intended to help dancers explore and understand dance choreography visually. Users would be able to record their choreography “blueprint”, and play it back via the floors colorful LED lights.

Objective: To make learning new dances or practicing old ones easier, through an intuitive, interactive dance floor connected to a system of pressure sensors and LEDs.
Users: Beginner to advanced dancers learning/practicing choreography.

Our team wrote use case scenarios exploring how a novice and experienced dancer might each utilize our interactive dance floor. We also created a storyboard, to demonstrate how our dance floor and its interface would be used.

Our early visual design involved 2'x2' tiles, with grids of 3-color LEDs and sensors. These tiles fit together like a puzzle to form a dance floor, allowing the user to create floors with a variety of dimensions to fit any space. At this stage, our floor tiles were intended to be one acrylic sheet, with hollows cut to hold the pressure sensors and LEDs. We created a low-fidelity prototype out of foam board, cut into puzzle piece shaped tiles, with round stickers representing each set of LEDs and sensors.

After presenting our initial design, we began revising our prototype to be more feasible and functional. We were planning to use three different colors of LED lights within the tile to indicate different layers or performances, but decided to limit this feature to one LED light. We also determined that our prototype would be limited to one floor tile, with four sets of LEDs and pressure sensors, due to time and technical constraints. We acknowledge that our project is limited to considering only the foot placement of dancers, and does not address other aspects of dance, including movement and gesture within 3-dimensional space.

Technical Implementation

Taking the lead on the technical implementation of our project, I connected the Arduino to our computer and created a basic circuit with one LED and a push button. After this short proof of concept, we ordered the remaining materials needed, including the 12”x12” clear plexiglass tiles and force sensitive resistors (pressure sensors). After researching the difference between analog and digital ports on the Arduino, I modified our sketch to use our new pressure sensor to turn on the LED, instead of the button used in our proof of concept. The next step was to add three more LEDs and FSRs to the breadboard, all functioning simultaneously.

With our four input/outputs functioning on the breadboard, we needed to prepare our floor tile to hold the pressure sensors so they could accurately receive user input. Initially, we hoped that we could enclose the sensors underneath the surface of the plexiglass, but the thickness of the material (while good for durability) blocked the sensors from receiving the needed pressure, even on the most sensitive setting possible. We decided to laser cut four rectangular holes into the tile, through which we could insert the FSRs and have them sit on top of the floor, while still keeping all wires underneath the surface.

I next cut the sixteen wires needed to extend the LEDs and FSRs from the breadboard to the floor tile, stripped the ends, and soldered them to the necessary components. We laser cut two more clear sheets of plexiglass to form the intermediate layers of our floor tile, containing channels for wiring and spaces to hold the LEDs and pressure sensors. According to our structural plan, these would be sandwiched together with a shiny black plexiglass sheet serving as the solid base.

With our Arduino code/hardware functioning at a basic level, and our tile ready to be assembled, I moved on to adapting this "Simple Simon Says" code to use as the basis of our record/playback functionality. We added a potentiometer to our breadboard to start/stop the recording mode, and two LEDs to indicate the recording state. This code uses a buffer to record the on/off state of the LEDs in an array, and can play back the pattern recorded. With this version working, I added code to record both the state of the LED and its identity, and playback all four pressure sensor/LED sets in our prototype.

Finally, we assembled the floor tile and secured the LEDs, wires, and pressure sensors. I created a box to contain the breadboard and Arduino Uno, leaving the wires exposed for debugging and attaching the potentiometer for easy access.

Functional Prototype

1. Computer running Arduino software.
The Arduino Software (IDE) allows us to develop code to connect with our Arduino hardware and upload/run programs. In the Arduino environment, these programs are called sketches and can be verified and uploaded to the connected board. For our sketch, we initialized the I/O ports each sensor and LED is connected to in the hardware. The board then waits for the potentiometer to reach a certain frequency (initiated by sliding the potentiometer control). This begins the “record/playback mode”. A red LED lights up and blinks a 5 second countdown to indicate the start of the recording. While recording is in progress, an adjacent yellow LED is lit. A buffer is used to record values of 0 or 1 to four arrays for each pressure sensor, indicating if the pressure sensor has been triggered or not. Additionally, the corresponding LEDs will light up as the pressure sensors receive a certain frequency. When the recording mode ends, the yellow LED will blink rapidly and turn off, indicating the switch to playback mode. After a short delay, the same buffer reads through the four arrays and activates the LEDs based on the value stored within the array. After playback mode has ended, the program returns to its “waiting” mode and plays a pattern on the LEDs while listening for the necessary input from the potentiometer. 

2. Arduino Uno and breadboard with connected wires/components.
The Arduino Uno’s microcontroller holds the sketch uploaded, and receives or sends the necessary information to the sensors connected through the breadboard. Due to the limited space available on the Arduino Uno, we had to limit the length of our “recordings” so the necessary arrays could be stored. For our implementation, we contained these hardware components in an open top box. The exposed wires allows us to debug our prototype as needed, and allows the red and yellow LEDs attached to the breadboard to be visible to the user as they communicate the recording/playback state. Attached to the top of this box is the potentiometer, allowing the user to easily access the slider to initiate the recording/playback mode. Our input sensors are attached to analog ports, allowing them to send frequency data to the microcontroller. The four LEDs contained within the tile are connected to digital ports, allowing them to communicate states of on/off.

3. Plexiglass layers with pressure sensors and LEDs.
Extending from the breadboard is a long stream of wires leading to our dance floor tile. The tile is constructed from four 12”x12” sheets of plexi glass. The bottom layer of black plexi serves as a base for our prototype. The 3 remaining layers of clear plexi serve as the structure to hold the wires, LEDs, and FSRs. Laser cut holes channel the wires on the bottom layer, while rectangular openings allow space for the four LEDs and FSRs to sit in the middle of their four quadrants. The pressure sensors sit on top of the tile, to allow for more accurate readings as the user steps on them. The LEDs are slightly offset from the FSRs so that they can remain visible while the user is interacting with the prototype.