Reflective Blog Post 2

My group initially wanted to build a remote controlled car for the final project. However, we figured that it would not be ideal with the limited time and materials we had and decided to build a toy mouse trap instead. The idea behind the final project is relatively straightforward: a block of ‘cheese’ is placed within the trap to seduce the mouse. When the mouse sees the cheese, it will walk towards it, entering the box and when it is inside (close enough to the sensor) the servo motor is triggered and the trap door shuts the mouse inside.

First, we cut an opening in the box to create the sliding door for the mousetrap. We cut off one of the flaps on the box and used it as the door for the trap. Second, we wired the Servo-Motor to the breadboard and the Arduino. The GND pin connected to GND, VCC to the 5V, and the third pin to PIN 9 on the Arduino. Third, we attached the single-sided arm attachment to the servo motor, taped the servo motor on its side on the top of the box, and attached the arm to the makeshift cardboard door using scotch tape. I used the servo motor sweep code learned in class, to make the servo move. Next, we attached the ultrasonic sensor to the breadboard (Trig pin to Pin 11, and Echo to pin 12). Followed by writing the code for the ultrasonic sensor which allowed it to display distance in cm. Then, we attached LED to breadboard, as well as a 100-ohm resistor. The most difficult part of the project was writing the code to activate the servo motor once the ultrasonic sensor sensed the mouse at a certain distance. However, we figured it out after doing some research and listening to explanations from our helpful instructors. After that, we secured the breadboard inside the box with the sensor facing the door. Next, we attached the string to the mouse’s nose and taped a loop to the side of the box to pull the string through. Then, we cut an opening at the back of the box for the wires and string on the mouse to go through. Finally, we uploaded the code and tested it several times. The door of the trap should be open when attempting to operate the trap. The string on the mouse should be slowly pulled through the backside of the box towards the sensor and into the box. The approaching mouse should trigger the servo motor to rotate the door, shutting the door and trapping the mouse. Pressing the reset button on the Arduino board will reset the trap door to the opening position to use it again.

We faced two major issues when building this project. Our first issue was writing the code since none of us had ever written a code this long and complex before. We finally achieved a working code through trial and error, as well as several tests. The second issue was that the ultrasonic sensor was detecting the string attached to the mouse instead of the mouse itself. This problem annoyed us greatly and we tried every possible method until we finally attached a loop to the side of the box and pulled the string through it. This method seemed to solve the issue and resulted in a fully functioning mouse trap.

My personal contributions to the project included the writing of the code, as well as brainstorming and trying out different ideas to solve our issues. I have learned a great deal from the time spent building this project. I learned that even a simple mouse trap project such as ours requires more effort and time than one would expect. With more time we could have improved upon our project by adding more features and making it more aesthetically pleasing. We were going to add a DC motor inside the box to imitate the sound of the mouse being crushed by it, but unfortunately did not have enough time to make it a reality. Most importantly, the course and the project has taught me that almost any task can be accomplished when circuitry is combined with the right code.