Desk Crit(ter) - a Desktop Robot That Responds to Knocking

This project was created as part of the course Computational Design and Digital Fabrication as part of the M.Sc ITECH program at the University of Stuttgart.

Authors: Ainsleigh Douglas, Simon Knorr, and Anishwar Tirupathur

This Desk Crit(ter) is a sound-responsive walking robot, developed for academic settings like desk critiques and seminar presentations. This little guy is designed to detect the "knocking applause," common in German academic settings, and move toward its source.

Our Desk Crit(ter) takes inspiration from BEAM robotics, which focus on simple electronics and mechanics to achieve autonomous behavior. We wanted to capture these same principles with our robot, while also incorporating the aesthetics of circuit sculptures, such as those of Mohit Bhoite.

The design aims to keep the circuit fully exposed, highlighting the electronics as a core part of the design. We also wanted the robot to take on a bug-like appearance to give it character and personality. This bug-like aspect is further highlighted with the awkward, clunky movement.

A. 2mm Copper Wire (for Frame)

B. 2mm Copper Wire (for Servo Motor and Battery Housing)

C. Arduino Nano

D. 9V Battery Clip

E. 9V Battery

F. 2x Servo Motors (with horns)

G. 8x 10mm Drilled Wooden Balls

H. 1mm Copper Wire (for Hooks)

I. 2x LEDs

J. 4x 1 MΩ Resistors

K. 2x 220 Ω Resistors

L. 4x Piezoelectric Sensors

optional

Bend two pieces of copper wire according to the plan. Insert the wires through the holes on the servo motor side. Begin by mounting both servos onto one frame, then proceed to attach the second frame. Insert the battery through the center to help stabilize and secure the structure. (Refer to Attached Plans).

(Refer to previous attached document)

Legs

Cut the 2 mm copper, so that you have 4, 210 mm length pieces. Using the provided template, bend the leg into shape.

Main Frame

Start by preparing the beads for the main frame. For the four corner hinges, cut circular grooves around the center of each bead using a lathe or a power drill. For the compartment mount, drill a 2 mm diameter hole on each side of the bead, perpendicular to the axis of the existing holes. Then, using the plan as a guide, bend the wire to form the frame and loop it around the grooves in the beads using tweezers.

The circuit is powered by a single 9V battery that powers both the Arduino Nano and the components. Solder the Servomotors to pins D2 and D10 on the Nano. The two LEDs should be connected to bins D12 and D13, with each using a 220 Ω resistor. Lastly, the 4 piezoelectric sensors should be attached to A0, A2, A4, and A6 on the Nano, with a 1 MΩ resistor connected to both power and ground helping to decrease the sensitivity of the sensor.

Step One: Upload Code to Arduino Nano

Code is attached to this step.

Step Two: Adjust Servo Motor Horns

Double-check that the horns of both servo motors are aligned with each other so that they move appropriately in accordance with the code.

This is a video showcasing the process of us developing this creature through various prototypes. We hope you enjoy building and experimenting with the desk critter yourself!