The Backend Cleaning Inspectors: Final Project

Group 8 – Backend Cleaning Inspectors


Tae Jun



One-sentence description
Our project is to make a device to improve security and responsibility in the laun­dry room. 

Links to previous projects



Task 1: Current User Locking the Machine

Task 2.1: Waiting User Sending Alert During Wash Cycle

-If the waiting user sends an alert during the current wash cycle, the alert will queue until the cycle is done. When the cycle is done, the current washing user will immediately receive a waiting user alert in addition to the wash cycle complete notification. The grace period will begin immediately after the wash cycle ends.

Task 2.2: Waiting User Sending Alert When Wash Cycle Complete

-If the waiting user sends an alert after the current wash cycle is complete, the current washing user will immediately receive a waiting user alert and the grace period will begin.

Task 3: Current User Unlocking Machine to Retrieve Laundry

Changes made since the working prototype used in P6

  • Improved our instructions that are displayed on the lcd screen for each task yet again in order to enhance usability based on the feedback we received from the test users

How and why your goals and/or design evolved

Since the beginning, we knew pretty much what our final prototype was going to look like.  Along the way though we have evolved it little by little according to feedback we’ve received from the user studies.  One important thing we have developed over the semester is the manner in which our locking mechanism physically locks the machine.  We thought of a lot of creative ideas at the beginning, but eventually narrowed it down to using a simple servo motor inside a carved piece of balsa wood that rotates the lock closed when the user locks the machine.  This made the most sense; however it would have to be improved if the product were to be commercially produced and sold in the future, as it would not be that hard to break the lock and thus gain access to the clothes within.  Another important feature that we have improved along the way is the set of directions that are displayed on the LCD screen as the user attempts each of the three tasks.  The instructions and information displayed have grown from the bare minimum in the beginning to become significantly helpful now with timers, error recognition, and more.

The most significant development in terms of our overall goals was that, as we implemented our system and received feedback from our test users, we shifted our focus more from the security of the laundry itself to the responsibility of the interacting users. In the beginning, our priority was mainly to keep the current laundry in the machine from being tampered with, even at the expense of the waiting next user. However, we began to realize that our target audience preferred that we focus more on responsibility between users. This resulted in shorter grace periods for current laundry users, as our testers generally expressed that they would be fine with their laundry being opened if they had warnings that they failed to heed. They expressed that, from the standpoint of the waiting user, it was more fair that they waited less time for the machine to unlock, given that the responsibility lay with the late current user.

Critical evaluation of our project

Overall, we view our project as a definite success. For such a short period of time, we have developed a working prototype that accurately resembles the system we envisioned in the first planning stages, complete with improvements and minor revisions along the way. With further iteration and development this could definitely be made into a useful real-world system. The only parts that are lacking in terms of production viability is an improvement of the physical locking mechanism that would guarantee the machine remained locked, as well as a more robust backend setup that would coordinate user interactions (through email servers, etc.) more effectively. Once these components have been implemented, our code would take care of the rest, and the product would be close to being complete for commercial use with a few more user tests along the way. 

We have learned that our original idea was actually a very good one. The application space definitely exists, as there is a high demand for security and responsibility in the laundry room. We have observed many emails on the residential college list serves about lost/stolen/moved laundry problems, and this is the exact problem our system sets out to solve. Our test users have also expressed enthusiasm and support for our project, and at one point we were even offered an interview by the Daily Princetonian. Our system seems pretty intuitive from the user tests, and we think we have designed a pretty good prototype for a system that serves the purpose it was set out to accomplish: protecting students’ laundry from irresponsible users and giving users peace of mind.

Future plans given more time

The most important implementation challenge for production to be faced before the product will be close to commercially viable is the physical locking mechanism.  Right now it is currently just a weak servo motor encased in a block of balsa wood.  This would need to be improved or changed entirely, for example by using an industrial electromagnetic lock. Upon finding an appropriate production lock, we would also need to find a secure, minimally-invasive way to mount the system to existing laundry machines.

Another component that we would improve would be our backend setup. We are currently hosting our email warning system on a Django server hosted on a free Heroku trial server. This system currently only sends warnings to a few hard-coded email address, as we do not yet have access to the school’s database of current student account numbers and their corresponding NetID’s.



List of third-party code used in our project

  • Key­pad: to control our keypad (

  • Liq­uid­Crys­tal: to control our LCD screen. It comes with Arduino

  • Servo: to control our servo motor used in the locking mechanism. Included in Arduino

  • WiFly Shield: to control our WiFi shield.

  • Django: to send out emails to users upon requests from Arduino.

  • Heroku: to host our email server.

Links to PDF versions of all printed materials for demo

Group 8 – The Backend Cleaning Inspectors

a. Your group number and name

Group 8 – The Backend Cleaning Inspectors

b. First names of everyone in your group

Peter Yu, Tae Jun Ham, Green Choi, Dylan Bowman

c. A one-sentence project summary

Our project is to make a device that could help with laundry room security.

d. Description of test method

We approached to people who were about to use the laundry machine in dormitory laundry room. We briefly explained them that we want to conduct usability test for our low-fi prototype and asked if they are interested. When they said yes, we gave them the printed consent form and asked them to read very carefully. We started our testing procedure when they signed to the form and we kept the form for records.

The first participant was a female sophomore. She was selected randomly by picking a random time (during peak laundry hours from 6-8pm) from a hat to check the laundry room in the basement of Clapp Hall. The student was using two machines to wash her impressive amount of laundry. She claimed to have waited until the previous user had claimed his clothes to use the second machine.

The second participant was a male sophomore. He was selected in a similarly random fashion using a drawn time within the heavy traffic time. The student was using one machine to wash his laundry, which he claimed was empty when he got there. This was strange, as the spare laundry bins were all full.

The third participant was a male freshman. He was selected in the same manner as the previous two subjects. The student was using one machine to dry his laundry, and claimed that he had no problems with people tampering with his things, although there was in fact someone waiting to use his machine.

The testing environment was set up in the public laundry room in the basement of Clapp Hall in Wilson College on Thursday, April 4th from 6-8pm, which we projected to be the peak time for laundry usage. The low-fi prototype components were set up in their respective places on one of the laundry machines– the processor was attached to the top, while the lock was fastened to the doors. Other equipment used consisted of the laundry machine itself. No laundry machines were harmed in the making of this test.

We first introduce ourselves to the participant and what we are trying to accomplish. After obtaining his/her informed consent and going through our demo script presented by Tae Jun, Dylan will give the system to the participant and explain the first task he/she has to perform for our test, using our first task script. The first task will be to load the laundry machine and lock it using our product. We then observe the user attempting task one. Upon completion, Peter then explains the second task. For the second task, the participant has to switch his/her role to that of the Next User trying to access the locked machine and send a message to the “Current User” of the machine. We all observe the participant attempting task two. Green will finish it up by explaining the last task to the participant, and we all again observe and take notes. The third and last task will involve the participant assuming the role of the Current User again and unlocking the laundry machine once their laundry is done. During all three tasks, we will rotate who is actually managing the changing of the screens of our product, so that we all get a chance to record notes on the different tasks. We then thank the user for his/her participation.

Consent Form: Link
Demo Script: Link

e. Summary of results

Overall, our results were quite positive. Users generally found no trouble in following the prompts, with the exception of a few minor things that they thought could be made more clear. The users often commented on the usefulness of the idea, citing their past negative experiences with people tampering with their laundry. They appreciated the simplicity of the keypad interface, as well as the “grace period” concept and other minor details explained to them. The only issues that came up (which we agreed to be Grade 3 Minor Usability Problems) were with the wordings of the prompts, which the participants would occasionally confirm with the tester.

f. Discussion

The results of our tests were very encouraging. We found that our idea was very well received and that the users were very enthusiastic about seeing it implemented. Despite the minor kinks in wordage and syntax, our lcd output prompts elicited the correct responses from our users and got the job done. In fact, the users’ enthusiasm for a possible laundry solution well overcame any potential problems with a minor learning curve, as all users expressed this implicitly or explicitly at one point in their testing. That being said, the exact wording, order, or nature of the prompts can always be changed in our software. In this testing, we confirmed that our product has a strong demand, an adequately simple interface, and an anticipating audience.

g. Future Test Plan

We believe that we are prepared to begin construction of a higher-fidelity prototype. Our physical components and interface design seem to be adequately simple and readable to begin building, and any issues that presented themselves involved the lcd output prompts or commands, which can easily be refined at virtually any stage in development. Thus, we believe our next course of action will be to begin the assembly and configuration of our hardware components in higher fidelity.

P3: Group 8 – The Backend Cleaning Inspectors

Group Number and Name
8 – The Backend Cleaning Inspectors


  • Tae Jun Ham (tae@)
  • Peter Yu (keunwooy@)
  • Dylan Bowman (dbowman@)
  • Green Choi (ghchoi@)

Mission Statement
We the Back­end Clean­ing Inspec­tors believe in a bet­ter world in which every­one can focus on the impor­tant things with­out the distraction and stress from mundane chores. This is why we decided to make our “Clean Safe” laundry security system. Stressing over laundry is by far one of the most annoying chores, and our “Clean Safe” laundry system will rescue students from that annoyance. Now Princeton students will be able to work with­out hav­ing to worry about the safety of their laundry.

Description of Our Prototype

Our prototype consists of two parts: 1) the user interface with a keypad and an LCD screen, 2) the lock. The user interface is where the two users, the Current User and the Next User, interact with the lock and with each other. It has a 4-by-4 keypad, three LED lights and a black-and-white LCD screen. The lock consists of two parts. One will be mounted on to the door of the washing machine, and the other on the body of the machine next to the door. There is a dowel that connects the two parts and acts as the lock. Also, there is a servo motor inside one of the parts that will lift/lower the dowel to release/lock. The servo motor will be controlled by the user interface.

Description of Tasks

  1. Lock­ing the machine (Current User)
    Our project lets the current laundry machine user to lock the laundry machine right after starting the laundry process. This task is three step process : (1) User inputs his student ID into keypad (on unlocked machine) (2) User press the “Enter” button on the keypad (3) User confirms his identity on screen by pressing the “Enter” button again.

    As shown in the picture above, our prototype mimics user operations on our module with keypad and lcd screen. “Enter” button is located on the right bottom side of the keypad.

    Above video shows testing process of this task with our prototype. As you can see, it is very simple to lock the laundry machine for added security.

  2. Send­ing mes­sage to cur­rent user that laun­dry is done and some­one is wait­ing to use the machine (Next User)
    This task lets next laundry user to send a message to the current laundry machine user. This task is very simple. User simply press button “Alert” to send the message to current user and the screen would show that the message is successfully sent.

    As shown in the picture above, our prototype mimics user operations on our module with keypad and lcd screen. User simply press the “Alert” button on the right side of the keypad.

    Above video shows testing process of this task with our prototype. Our system allows an easy for the two users to interact with each other.

  3. Unlock the machine (Current User)
    This task lets the current laundry machine user to open the laundry machine with his student ID. This is three step process : (1) User inputs his student ID into keypad (on locked machine) (2) User press the “Enter” button (3) User confirms his wish to unlock the machine by pressing the “Enter” button.

    As shown in the picture above, our prototype mimics user operations on our module with keypad and lcd screen. This task is very similar to the Task 1 except that this task is done on the already loc
    ked machine. This similarity makes our user interface more intuitive.

    Above video shows testing process of this task with our prototype. As shown in the video, it is very simple to unlock the door and retrieve the laundry. Also, with the extra security provided by our machine after the laundry is done, it will be unlikely for the Current User to lose any of his/her laundry.

Discussion of Prototype
We made our prototype using cardboard paper and the plain white paper. Cardboard paper forms the base of our prototype and white paper pieces work as components on the base. In general, making the prototype was a straightforward process. However, we had to modify few parts of the prototype (e.g., LCD screen interface) to make our prototype intuitive enough for someone to test it without too much explanations. After modifications, many testers were satisfied with the prototype and we now believe our low-fidelity prototype does its job effectively.

P2 – The Backend Cleaning Inspectors

Group Number

Members and Their Tasks

  • Tae Jun Ham (tae@): Designed the lock system.
  • Peter Yu (keunwooy@): Conducted an interview, helped with the design and the write-up.
  • Dylan Bowman (dbowman@): Conducted an interview, helped design the product and answer questions.
  • Green Choi (ghchoi@): Conducted an interview, drew the sketches and helped with the write-up.

All members contributed pretty much equally.

Problem and Solution Overview
Our idea addresses the common problem at Princeton of strangers tampering with, moving, or even stealing other peoples’ laundry that is left in the machine after the cycle. Our solution is to build a locking system to provide security. It will take Princeton NetID from the user and lock the machine until the grace period (10 minutes or so after the end of the cycle) is over. The user will be notified about the status of the machine via email. Other users who are waiting to use the machine can inquire the current user when he/she will retrieve the laundry by pressing a button on our device. By providing security and enabling the communication between users, our system can effectively prevent theft and tampering with laundry.

Description of Interviewees

  1. Male, 21, Junior, Econ Major, from Pennsylvania. Varsity soccer player. Normal/preppy style. Laundry every three weeks
  2. Male, 21, Senior, Architecture Major from Boston. Normal/preppy style. Laundry every month
  3. Female, 19, Freshman, No major yet from San Diego, California. Athletic style. Laundry once every month.

We chose these people, because they were doing their laundry or waiting to do their laundry in the laundry rooms on campus. These people are perfect candidates for our CI interview as they are our target users.

CI Interview Description
We waited in the laundry rooms of various locations on campus to interview people who came to do their laundry. We would then politely ask them to participate in a short interview, and we would ask them questions about their laundry process and related things. We kept things focused on specific things they did during their laundry process and what specific things were important or not important to them during that process. Some example questions we asked during our interviews: Describe your typical laundry routine in as much detail as possible. Do you stay while your laundry is running, or do you go do other things in the meantime? Do you usually retrieve your laundry as soon as it’s done or do you wait a certain amount of time (either accidentally or on purpose) before you do? Have you or your roommates ever had any problems with people taking your laundry out of the machines before? When d you usually do your laundry? And many more…

One theme that was common in our interviews was that people did not wait in the laundry room for their laundry to be done. They would usually return to their rooms or another place on campus to do work or other activities and return to get their laundry once it was done. This would imply that most people on campus do not wait around while their laundry is running. This is pretty easily explainable: Most people at Princeton are incredibly busy. Students have school work, real work, job applications, sports practices, musical practices, social activities, etc. They need to use any possible time they have to do these things and waiting around for their laundry to finish is not an option really unless they are doing work while they wait (which is what one of our subjects actually does). However, most people prefer to do their work in their rooms or a library rather than in a laundry room, and thus most people do not remain around to watch their clothes.

Another theme that was common in our interviews was that they seldom came back on time to retrieve their laundry, usually coming back 15 to 30 minutes late. Again, people are busy doing things and sometimes those things don’t end exactly when their laundry ends. Or sometimes people just forget their laundry is running. Both explanations have a hand in this effect, and our product can help with both. Only a few differences were observable. First, the subjects all had different levels of how far they would go when dealing with another person’s laundry. One said that he would take out a person’s laundry from either a washer or dryer if it was done running. Another said that he would only take it out of the dryer. This is interesting, but the fact still exists that people do take things out of machines when people don’t want them to and that’s where our product comes in. One last difference is the interview with the girl revealed concerns about the privacy of her clothes. We think this is fairly straightforward in that girls are more conscious about their clothes being seen or touched by other people. We feel that this feeling is in the majority among girls at Princeton.

Answers to 11 Questions
1. Who is going to use system?
– There are two parties involved in the laundry rooms on campus: people who are using the washing machines (the Current User) and people who are waiting to use the washing machines (the Next User). Let’s assume laundry thieves are included in the second group.

2. What tasks do they now perform?
– As of now, the Current User simply brings his/her laundry to the laundry room, puts the laundry in the machine, goes back to whatever he/she was doing, and then comes back to retrieve the laundry.
– The amount of time between when the laundry is done and when the student retrieves his/her laundry varies widely, and it’s one of the main causes of the temperament of laundry and theft.
– The Next User, when there is no available laundry machine, usually takes finished laundry out of the machine to use the machine. Thieves will steal the laundry that has been taken out of the machine.

3. What tasks are desired?
– As for the Current User, protection from other students taking their stuff out of the machines or steal it without knowledge of the user is desired. The task that we will provide with our product will be to prevent potential thieves or laundry miscreants from messing with or stealing the user’s clothes, something that is very personal and meaningful to most students.
– As for the Next User, a channel to communicate with the Current User of the laundry machine is desired. It could be a button that will send the Current User of the machine a message that someone wants to use the laundry machine. The Current User can also send a notification back to the device when he/she will be back. This way, the Next User knows when the Current User will be back and is less likely to take the laundry out, thereby preventing theft and temperament.

4. How are the tasks learned?
– Instructions will be emailed to student residential listserves
– Instruction placards or flyers will be posted in laundry rooms and on machines
– Instruction manual will be included with the product.

5. Where are the tasks performed?
– In public laundry rooms across campus with wifi connections

6. What’s the relationship between user & data?
– We deal with few data which include laundry machine status and user’s Princeton NetID. For laundry machine status, we will let all users to see it in remote location via separate website. For user’s Princeton NetID, as this information is private,

7. What other tools does the user have?
– Virtually all users will have access to constant communication through email. Our product will take advantage of this by emailing the user when certain actions occur, such as their laundry being done, or when someone waiting to use the machine presses a warning button on the locking unit during the wash cycle or during the waiting period.

8. How do users communicate with each other?
– One important way our product will facilitate important communication between users is through the use of a certain button that serves the following purpose: Our user’s laundry machines will remain locked by our product for a certain period of grace time after the laundry is done. If someone is waiting to do their laundry and all of the machines are taken, they can press the button once at any time during the cycle. Our product will then send a quick email to the user alerting them that someone is waiting to use their machine and that they should retrieve their laundry as soon as possible after its done. This is an important way that the users of our product will communicate with each other.

9. How often are the tasks performed?
– Per individual user: Anywhere from once a week to once every 3 weeks.
– Campus-wide: Frequency depends on the time of the day and the day of the week. Students tend to do their laundry in after-class hours, later at night, and on the weekends.
– It is here noted that the late night hours are often used to avoid the very problem of laundry tampering that we are trying to solve.

10. What are the time constraints on the tasks?
– Users washing their clothes have the time constraint of the laundry cycle time, plus the varying time constraint of the grace period time that is determined based on the laundry room traffic at given times or days of the week. This grace period may be determined by survey or dynamically as users use our machines.

11. What happens when things go wrong?
– When the grace period is over, our product will automatically unlock. This means that anyone can get to the current user’s laundry. This isn’t exactly “things going wrong” as the product was designed this way. This situation would be more of the user’s fault. One thing that could wrong is our product malfunctions and either: 1) unlocks when it shouldn’t and allows things to be stolen. Hopefully our code can have some fallback mechanism to at least alert the user that their laundry is no longer locked. 2) remains locked when it shouldn’t be. This is a bit more difficult to deal with as there really is no other way to fix this other than physically breaking into the lock. Thus, we must be extremely careful to not allow this to happen in our product.

Description of Three Tasks
1. Current User: Locking the machine:
– User inputs netID into locking unit keypad. This netID is used as the password for unlocking the machine, as well as the email address used to send warning messages by the locking unit (and the next user).

2. Next User: Sending message to current user that laundry is done and someone is waiting to use the machine:
– The next user waiting for the machine (when no other machines are open) can press a button at any time during the cycle. When the button is pressed (only once per cycle), our product will send an email to the current user saying that someone is waiting to use their machine after they are done and that they should go retrieve their laundry as soon as possible after it is done.
– Current Difficulty with current technology/tools: Close to impossible. There is almost no way to tell who is using which machine and just as hard to contact them even if you do know who is using it (assuming you’re not friends with that person).
– Difficulty with our Product: Easy. Literally as easy as pressing a button.

3. Current User: Unlock the machine:
– If the machine is currently locked (during the grace period), the current user must input his netID to unlock the door and extract his laundry.

– Current Difficulty with current technology/tools: Very easy. Just open the door of the machine…
– Difficulty with our Product: Easy/Moderate. The user will simply input his netID during the grace period after the wash cycle, unlocking the door and allowing him to take out his pristine, un-tampered-with laundry. The only difficulty with this step is the user forgetting, ignoring, or failing to comply with the warning messages and not unlocking the unit on time. This will result in the automatic unlocking of the door and the giving up of the laundry’s sanctity and innocence to the winds of fate.

Interface Design
Our system provides the user with extra security for his/her laundry and better means of communication between users. After starting the laundry machine, the user will lock it with our device by entering the NetID. Our device gives the user a short grace period after the laundry is finished. During this time, the Next User can send the Current User an email by simply pressing a button on our device, thereby notifying the Current User that there is a person waiting to use the machine. This will prompt the Current User to retrieve his/her laundry. If the Current User needs more time, he can simply reply to the email to let the Next User know when he/she will be retrieving the laundry.

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Resistance is futile


  • Keunwoo Peter Yu
  • Dylan Bowman
  • Green Choi
  • Taejune Ham

Group Number
What we built
We’ve built a lighting system that reacts to the background light and pressure. We wanted to build a lighting system that automatically dims itself to save energy when there’s enough background light, and only turns on if necessary e.g. when a person is standing in front of the door thereby applying pressure to the sensor. Our system only turns on the LED lights when there’s pressure and low background light as intended. We picked arbitrary thresholds for background light and pressure, but in the future, we’d like to select these values after a more systematic analysis.

Our idea applied to a closet

Our idea applied to a closet. Depending on the background light, the light bulb adjusts its brightness accordingly. Also, it only turns on when a person is standing in front of the closet looking for something, thereby saving energy.


Our idea applied to the toilet. Depending on the background light, the brightness of the room is adjusted. Also, the light turns on only when you’re sitting in the toilet.

Entrance of a House

Our idea applied to the entrance of a residential house. Only when someone is standing at the entrance does the light turn on. Also, it adjusts its brightness based on the background light.

Pictures and Video

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List of parts

  • 2 10K Ohm resistors
  • 2 LED Lights
  • 1 Force-sensing Resistor
  • 1 Photo Sensor

Complete the circuit as shown in the picture below.


// pin numbers for LED
const int greenLED = 11;
const int yellowLED = 10;
const int lightSensor = 0;
const int forceSensor = 1;
const int LIGHT_MAX = 255;
const int FORCE_THRESHOLD = 400;
const int LIGHT_THRESHOLD = 100;

// variables
int light = 0;
int force = 0;

void setup() {
  pinMode(greenLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);

void changeLight(int light) {
  analogWrite(greenLED, light);
  analogWrite(yellowLED, light);

void loop() {
  light = analogRead(lightSensor);
  force = analogRead(forceSensor);
  if (light < LIGHT_THRESHOLD && force > FORCE_THRESHOLD) {

Assignment 2 – Peter Yu

A description of how you conducted your observation (who, where, when).

  • HCI class
    I started by observing students in the HCI class. The most common activity students did during the 10-minute period was to check their emails. Quite a number of people read articles online. Also, a few worked on their assignments for other classes (i.e. coding), which they continued to work on though the actual lecture.
  • An English Major
    I interviewed a friend of mine who is an English major before her precept. She commented that she often feels the 10-minute period before her class is not long enough to do meaningful work. From my observation, I noticed that she rotated between checking her emails, checking her Facebook and reading news articles.
  • An MAE Major
    I also observed another friend of mine who is an MAE major before his class. The first thing he did as he sat down in his seat was to pull out his work for another class. However, this quickly ended when another student sat next to him and started chatting with him. He then pulled out his smartphone, read some comics and played a quick mini game.


  1. Princeton Amazon Mechanical Turk, allowing students to get paid for doing simple tasks during the 10 minute period.
  2. App that gives you a funny Internet video for you to watch during the 10 minute period.
  3. App that gives you informative, but random facts to read during the 10-minute period.
  4. 10 minute work out routine.
  5. SnapChat for 10 minutes. Students can send outrageous pictures to friends which are only visible during the 10 minute period.
  6. Betting game on the first (second or third) word the professor or preceptor will say.
  7. 10 minute digest of news that happened during the previous class.
  8. 10-minute summary of the upcoming lecture.
  9. App that tells you where your friends are sitting, or tells your friends where you are sitting.
  10. Mental warm-up app. Shows you a simple puzzle or an article that’s relevant to your class.
  11. Class crush. Send a note to your crush in your class during the 10 minute period, and they will receive the message after class.
  12. Class bingo. Submit bingo words during the 10-minute period. Played throughout class, and winner is announced at the end of the lecture.
  13. App that provides a digest of notable things that happened in the users’ social networks during the previous class.
  14. A campus GPS app that finds the optimal path given the places you need to go.

Why I chose the two ideas.

  • App that provides a digest of notable things that happened in the users’ social networks during the previous class.
    The most common activity students did during the 10-minute waiting period was to check their social networking websites or emails; however, 10 minutes is not often long enough to check everything that has happened during the previous class. This app will help students efficiently check whatever social networking service they choose during the 10-minute period.
  • Betting game on the first (second or third) word the professor or preceptor will say.
    It is always an inconvenience when some students come to class late, because there is not a strong enforcing mechanism or an incentive. However, if we make a game that makes it advantageous to come early to class, as the betting game I thought of, I predict that the number of students who come late to class will decrease significantly.
  • An app that allows the user to share notes during the 10-minute period.

10-minute digest

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Fastest Route

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User Testing (10-minute Digest)

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Insights from Testing.
All the users did not have too much difficulty using the application: it is really a simple aggregation application. However, I noticed that some users try to swipe the tabs to the side instead of the intended vertical direction. People really liked the fact that the application filters notifications by time frame. However, there were recommendations about allowing the user to directly interact with other social networks. Also, users wanted a “see-all” feature, which allows the user to see the notifications from all social networks in one place.

The Backend Cleaning Inspectors


Keunwoo Peter Yu
Green Choi
Dylan Bowman
Tae Jun Ham


1. Motion Based Coding environment  (Kinect or Leapmotion)
– Uses gestures to reach, move, and otherwise manipulate code.

2. Physical Therapy (Kinect)
– Shows correct form on screen and allows user to try and mimic it
– Records best match, progress in getting better, warnings to rest when getting worse

3. Coffee Order Counter from Line (Arduino, etc.)
– Have switches that can be accessed from line that allow multiple orders to be placed
– Could be used by coffee store customers (Starbucks, etc.)

4. Security system based on gestures (Kinect)
– Use a special gesture as the key to the system.

5. Outfit recommendation system based on weather (Arduino)
– Detect the current temperature, wind, etc. and make recommendations on the day’s outfit.
– Could be used to help senior citizens go through their daily dressing routinesIMG957096

6. Music recommendation based on facial expressions (Kinect or webcam)
– Choose music to play based on the facial expression the user makes

7. Refrigerator camera to recommend recipes based on contents of fridge
– Recognizes ingredients in fridge and suggests recipes that could be made from those

8. Refrigerator compartmentalized tracks number of accesses to warn against obesity (Arduino)
– Could even apply to non-refrigerator – just use it where you store the most unhealthy items in your kitchen

9. Door control based on pattern or face recognition, primarily for cats and dogs (Kinect)
– Guards against strays and dirty inferior creatures like raccoons and possums

10. Attachment to measure acceleration of punches or kicks. (Wii controler)
– Measure the power and speed of punches or kicks using the Wii controler for entertainment or training purposes.

11. A device  to keep you awake in class based on variable resistor.
– Requires constant change in resistance to not shock you.
– No change indicates falling asleep.

12. Presentation aide based on gestures. Kinect or accelerometer.
– Pointing causes laser on screen that observers can follow
– Swiping allows next slide or previous slide to come up

13. Presentation aide based on voice. (Arduino)
– “Next” or “Back” moves slides forward or back
– “2nd point” highlights second point on slide

14. Voice or gesture combination for pet doors or food dispensers
– Teach cat or dog certain combination of actions that allows pet-door to unlock or food to dispense

15. Garbage can attachement to detect fullness and make alarm (Arduino)
– Once garbage in the bin passes certain height, sounds an annoying alarm so that people actually empty the bin.

16. Webcam device that tells you optimal chiropractic chair height.
– Takes a picture with the webcam and see if the chair is at the optimal height.

17. Device to measure motion, lack of which will trigger alarm to keep you awake.
– Security Guards: Administers caffeine or stimulants.
– At Home: Alarm sounds.

18. LED flash light on your glasses that adjusts brightness according to environment’s light (Arduino)
– Button to turn function on and off.

19. Wireless motor to attach to existing switches using remote.
– Remote control lighting, etc. to existing switches.

20. Auto-spotlight (or fan) that tracks moving objects (Kinect)
– Pre-game functionality

21. Autofan for temperature changes or humidity changes.
– Sensor outside window tracks changes in temp/humiditiy/possibly others (precipitation)
– Changes fan speed/power in room to adjust

22. Sensor in shoes to measure how high you can jump.
– Measures the weight and the force the person exerts to calculate how high he can jump
– No need for a wall with a measurement tape.

23. Light inside bag turns on when a girl opens it and there’s no environmental light.

24. Toothbrush holder that lights up brighter and makes sound warnings if you don’t take it out for too long (like longer than a day or something). (Arduino)
– Light will get brighter, sounds get brighter and more frequent.

25. Toothbrush attachment with accelerometer that recognizes proper brushing technique and length (Arduino)
– Good for kids. Proper recognition prevents false brushing.

26. Toilet attachment that vibrates when the user has been sitting for too long. (Arduino)
-Time management for toilet gamers.

27. Bathroom hygiene circuit that makes sure faucet is turned on after flushing.
– If you flush and then don’t turn on faucet in next 30 seconds, starts buzzing annoyingly, or locks the door.

28. Security system that tracks incoming and outgoing people in a building.
– Ensures that number is even at end of day, or just # of people in building.

29. Laundry Security (Arduino, we picked this idea)
– Can tell if washer/dryer has been opened before it is done (people moving your laundry because nothing else is open)
– Possibly takes a video if it does, or buzzes alarmingly to warn them.

30. Vending machine add-on ensures product dispenses after purchase with motion sensor at the bottom.
– Prevents vending machine damage from people kicking it after stuck items.

31. RC car that follows you around with a flashlight in dark areas.
– Can help certain jobs like plumbers, etc. explore small compact areas like pipes or under houses
– Can possibly turn a different color if sensing hear or light to alert operator of its presence

32. Self-organizing chairs or other furniture objects.
– By remote positioning

33. Chair mat with sensors that tell you whether your posture is okay or not.
– If uneven left or right it beeps to tell you scholiosis alert.

34. Motion sensing screensaver functions for TV. (Kinect)
– Can tell if you fell asleep, and then turns off TV

35. Simple hand/fingertip scanning device. Paper to digital.
– Scan finger over lines of text and it comes up on the screen

36. Book reader that reads out loud as your scan in pages.

37. Remote Controller Finder (Arduino)
– A pair of devices. One is attached to the remote controller, and the other to the actual device (e.g. TV)
– When the remote controller is lost, press the button on the device.
2013-02-22 21.57.24

38. Coffee/Tea Temperature Assistant
– A device you can attach to the cup of your favorite hot beverage.
– Tells you when the optimal temperature has been reached.
– AKA Thermometer 😉

39. Measuring system with fridge that measures BMI and tells you when you’re being too unhealthy.
– Locks the fridge door if you’re gaining obesity points.

40. Video game controller that has biometric ID-ing device that locks the game if you’re playing too much.
– Parents can control how much their kids play video games

41. Toilet device that measures the contents of your urine and warns you with a light if you’re dehydrated or have some kind of problem.
– Too high blood sugar, cholesterol, etc.
– Activated upon flush

42. Public laundry machine that requires your phone number or NETID to activate.
– Texts you a reminder it’s done or before it’s done
– Phone number needed to open the door until after 15 minutes after cycle
– Bills the number a late fee if you don’t show up on time!!!!

43. 3D space explorer (Kinect or leapmotion)
– Can view the solar system and beyond using hand gestures.
– Great for science classes.

44. Biometric sensor smartphone attachment that calculates levels of alcohol or other drugs and locks certain features accordingly.
– Can lock text messaging or calling for certain predetermined numbers. (Family, girls, etc.)

45. Motion based movie player. (leapmotion or Kinect)
– Use intuitive gestures to play/fast forward/rewind/pause movies or any kind of videos.
can change volumes and stuff
2013-02-22 22.04.37

46. Device that uses motion detection or accelerometer to determine when you are dozing off and begins recording sound and/or video.
– Allows sleepy people to review what they would have missed.

47. Thermostat that only opens when a hand is touching it.
-Use variable resistor; it it’s at neutral state, don’t open the lid.

48. Kinect sensor in car that recognizes specific hand motion to start the engine.
– Could be extended to locking/unlocking the doors.

49. Radio sensor that flashes warning light to indicate when police or public safety have entered the building
– Could also use facial recognition to scan for faces older than college age.

50.  App that allows scientists to examine the 3-D structure of atoms or molecules, etc.  (Leap Motion)
– Great learning tool, would be awesome for classes

51.  App for a new textbook interface on the Leap Motion
– Can turn pages, highlight, write in margins, mark favorite pages etc.
– No longer have to buy textbooks, can store all of them on your computer
– Could make it more general as a pdf reader, since most notes and textbooks come as pdfs.

Why We Picked Idea #29

We the Backend Cleaning Inspectors believe in a better world in which everyone can focus on the important things without the distraction and stress from mundane chores. This is why we chose idea #29: stressing over laundry is by far one of the most annoying chores, and we’d like to rescue people from that annoyance. With our new “Clean Safe” laundry security system, people will be able to work without having to worry about the safety of their laundry.

Project Description

  • Target User Group: Our broad target user group will be anyone that uses a public laundry machine.  Our product will allow them to have the peace of mind that their laundry will not be disturbed.  However, narrowing our focus to users that we have access to, we can say that our specific target user group for this project will be students at Princeton University who use Princeton laundry services, especially those who have had problems with their laundry being messed with (either taken out before it was done to make room for someone else’s laundry or something similar) while they were not in the laundry rooms.  Our target user group wants a product that will allow them to have confidence that their laundry will not be disturbed when they leave the room.  Very few people who use the laundry services at Princeton stay there and watch their laundry until it is finished. Our product will essentially do that for them.
  • Problem Description & Context: Our idea addresses the common problem at Princeton of strangers tampering with, moving, or even stealing other peoples’ laundry that is left in the machine after the cycle. The context is the public laundry system at Princeton in which users do not necessarily know when washed or dried laundry will be removed by its owner. This leads to people moving the laundry to potentially dirty places like the floor, where in many cases it is lost or even stolen. This problem may be affected by the time and date, as many students do their laundry before or after classes or on weekends, as well as location, as areas with fewer laundry rooms will be more frequently in demand. These factors can be accounted for statically or dynamically with machine usage data. We propose to solve this problem with an system that will enhance security, responsibility, and efficiency in the laundry room. We hope to take identifying input from the users of the laundry/dryer machines, such as Princeton NetID, phone number, etc. and use it to 1.) send them SMS, email, or other warnings at time intervals and 2.) require this information to unlock the laundry machine until a certain grace period after the cycle has completed (intervals will be calculated based on time, date, and location). This idea may be expanded or refined depending on our capabilities and other environmental factors we encounter in the process, such as adding a fine to late laundry owners.
  • Why Arduino? Arduino offers a good solution because our users will need to input identifying information(netid, phone number, passcode, etc.). We can accomplish this by programming necessary buttons on the Arduino platform. The attachable LCD displays will also come in handy to display remaining times, warnings, etc. Also, Arduino and its supporting programming languages allow us to send SMS and email notifications to our users. In general, Arduino’s compact size and simple construction will allow us to program a clean, user-friendly interface device to attach to existing laundry machines with minimal modifications.