Arduino Operation

Abstract

The subsystem of physical project components will be completed for April 3rd. This will include both mechanical components and electrical components. The mechanical components are a laser cut game board, 3D printed organs to fit into the body cavities designated by the board, and forceps that we will externally source. The electrical components are force sensors to be fit to the body cavities, a DC buzzer, and, of course, a red LED for the nose.

The IoT application of this project will be completed for the April 17th deadline. The game will update graphs relaying the pressure sensor readings in real time.

Writeup

This project is a recreation of the classic board game Operation. Aside from wanting to design a fun, game-oriented project, we chose to build this due to the wide variety of sensors that could be incorporated into the circuit.

On the first demo day, we had most of the electrical components working including the game board laser cut from acrylic with three body cavities. The body cavities were roughly wrapped in aluminum foil. The foil worked to complete the circuit when it was touched with a pair of metal tweezers that were also hooked into the circuit. There were also force sensors in two of the body cavities, a red LED in the nose, and a DC buzzer all functioning in the circuit. The code worked to set off the buzzer and the LED whenever the tweezers came in contact with the foil in the body cavities.

For the final demo we redid the foil wrapping the body cavities to make it more stable. We also incorporated a third force sensor as well as the IoT component. The IoT sent force readings via Wifi from the three sensors to a ThingSpeak page so a user can confirm when they have removed all of the items from the body cavities.

We wired in three force sensors, an LED, and a DC buzzer using a Wifi board. The force sensors used a 3.3 kΩ resistors and were wired to analog pins on the Arduino. The LED had a 200 mΩ and was wired to a digital pin. The buzzer did not use a resistor and was wired to a digital pin as well. Each component of the circuit was placed under the part of the game board it was connected to. For example, the red LED was placed at the top middle of the breadboard where the nose of the man on the board is located. The game was implemented by breaking the circuit to the LED and the buzzer and connecting one side to the metal tweezers and one side to the foil wrapped around the body cavities. This way when the tweezers touched the foil, the circuit was completed, and the LED lit up and the buzzer sounded.

The code controlled when the LED lit up, when the buzzer sounded, and the data collection from the force sensors. The LED was always set on high and the buzzer was always on, but they only ran the code when the circuit was complete (the tweezers were touching the foil). The data collected from the force sensors was printed to the serial monitor and sent to ThingSpeak. The serial monitor functionality was to allow us to test while we were building the circuit. The ThingSpeak functionality allows a user to easily confirm that there is no pressure on any of the sensors, and therefore all of the objects have been successfully removed from the cavities.

This project is a recreation of a product that is already sold, so many of the components build off of the same concepts, such as the use of the aluminum foil. As a result, to reach the quality standards of a real game that is sold, the manufacturing process would need to be more sophisticated and incorporate sturdier components. For example, wire could be used, rather than aluminum foil, which tears easily, to reinforce the edges with a much more solid material. Our board also consists of a sheet of acrylic that has to be placed on top of the breadboard, whereas the box design of the real game improves portability and protection of the electrical components.

Improvements that could be made to this project pertain mainly to its portability. Whenever the project was transported, stored in a locker, then taken back out, wires and other circuit components would pop out or move, so we repeatedly needed to debug the circuit. Since the game board itself was laser cut from scrap material, there was not a sufficient amount of acrylic to create a full box, which would have better encapsulated the electrical components underneath. The tweezers were also fastened to wires using shrink tubing that was tightened using a heat gun; however, successful use required the user to pinch down the wires while holding the tweezers. As a result, using more narrow shrink tubing would improve connection of the metal of the wires to the metal of the tweezer, making the tweezers easier to use. The game could be made more interactive through the incorporation of more kinds of sensors, such as a tilt sensor or accelerometer that could detect when the user was trying to cheat by moving the board rather than exclusively using the tweezers. The IoT application could also send the user a text or email stating, for instance, “you win,” “you lose,” or “stop cheating.”

Built With

• arduino