Lab

Recommended Tools

In addition to the resources that the course provides, students may find it useful to obtain the tools below:

  • wire cutter
  • wire stripper
  • needle nose pliers
  • screwdrivers
  • hex set (ball ends)
  • electrical tape
  • small scissors
  • a small file

Lab Resources

The Srivastava Senior Design Lab (2070 ECEB) is dedicated to ECE 445 usage. This lab provides you access to a vast array of lab equipment, hardware, and software for your use in developing and implementing your senior design project. In addition, course staff will make themselves available in this lab during their office hours to provide guidance on your project throughout the semester. It is our intention that this laboratory space provides you and your team with all the tools you would need to develop and test your project (within reason!). If there is something that you require in the lab to complete your project that does not exist in the lab, talk to your TA and we will see if we can remedy the situation.

Lab Bench Reservations

If and when the semester gets so busy that finding a lab bench to work at becomes difficult, please make use of the Lab Bench Reservation System in PACE. Reserving a lab bench will guarantee priority access to that bench, even when the lab is busy. To use the tool, after authenticating in PACE, you will see a page with a title "Signup for lab bench" with some text and a large table below that. The table shows the schedule for each bench on a given day (use the orange arrows or "Go To Date" text box to see a different day).  You make your reservation by simply clicking in a grid cell in the table, which will turn the box green. Click on it again to un-reserve the bench (and the box will turn white again).  Benches that are already reserved by another group will be denoted with a yellow box (you can hover your mouse over a yellow box to find out what group has reserved the bench).

A few ground rules:

  1. You may use a lab bench (a) during a time for which you have it reserved or (b) any time during which it is not reserved in the system (on a first-come-first-served basis). However, if you are working at a bench that is unreserved and somebody reserves it using the online system, the group with the reservation gets the lab bench.
  2. There is a limit on the amount of time for which you can reserve benches in 2070 ECEB.  The limit is currently a total of 4 hours of total bench time in the lab per group per day (e.g., 2 hours at Bench A and 2 hours at Bench B would max out your team's reservations for the day).  While this may seem restrictive, keep in mind that the course serves more than 60 groups in a typical semester and the lab has only 16 benches.  Also keep in mind that you can work at a bench if it is unreserved.
  3. Some lab benches have specialized equipment at them, such as digital logic analyzers.  Try to reserve the lab bench that has the equipment that you need.
  4. Cancel reservations that you will not need as soon as possible to give other groups a chance to reserve the lab bench.  You can cancel a reservation up to 1 hour before time and not have it count against your daily allotment.
  5. Conflicts and/or reports of people not following these rules should be sent to your TA with the course faculty in copy.
  6. Above all, be courteous.  Especially near the end of the semester, the lab will be full most of the time and stress will abound.  Clean up the lab bench when you are done with it.  Start and end your sessions on time.  Be patient and friendly to your peers and try to resolve conflicts professionally.  If we notice empty lab benches that have been reserved, we will cancel your reservations and limit your ability to reserve lab benches in the future. Similarly, do not reserve more time than you will need.  If we notice that you are frequently canceling reservations, we will limit your ability to reserve lab benches in the future. Finally, do not try to “game” the system and reserve a bench for 30 minutes every hour for eight hours. We will notice this and revoke your ability to reserve a bench.

Lab Rules

There are two overriding rules of working in the Srivastava Senior Design Lab. First, be safe. Second, be courteous. Lab access will be revoked if you fail to complete the required laboratory safety training by the deadline or if you break any of the lab rules. Specific points and examples of what we expect:

Breaking the rules or exhibiting bad laboratory etiquette will lead to a loss of points and/or revocation of laboratory access.

Lab Equipment Rules

Do not remove any equipment from the lab. Students may not change the connections on equipment without TA approval. Any approved changes that are made should be undone before leaving the lab. If a bench instrument is malfunctioning, a red repair tag should be placed on it and you should notify your TA. This alerts the staff to the problem, and allows the Electronics Services Shop to fix the problem.

When using a piece of laboratory equipment for the first time, please ask a TA for help. If you are inexperienced with a piece of hardware, do not assume that it is broken just because you cannot figure out how to use it. Similarly, if you use a piece of equipment to test your project and the equipment does not perform the way you think it should, do not assume the fault is with the equipment, and do not try again with equipment on another bench. Rather, stop and make absolutely sure the problem is not with your connections or project.

If you break any laboratory equipment, you must tell your TA within 1 business day. Any attempts to conceal breakage will result in an F in the course.

Room Access

The lab room (2070 ECEB) is on the electronic key-card system. The Department automatically adds room access to the building and the lab for all students on the roster. You will need a “prox enanabled” I-Card to swipe into the room. If the door does not open after several attempts, you may need to get a replacement card. Room access is automatically restricted to faculty and TAs during official breaks (i.e., Thanksgiving, Christmas, and Spring Break).

Computer Access

The lab computers are EWS computers and are setup like other Windows-based EWS systems you are familiar with. Standard EWS rules apply to these machines. In particular, please store any/all files you generate on a network drive or in the cloud. The C: drive should not be used for any personal material, since it is unprotected and is available only on the particular machine where it was originally stored. A particular computer may be cleared and reconfigured at any time for maintenance reasons.

In addition to the desktop computers, EWS maintains the printer in the lab. You are free to use it to print documents related to your project, but be aware that this printing counts against your standard print quota.

UV Sensor and Alert System - Skin Protection

Liz Boehning, Gavin Chan, Jimmy Huh

UV Sensor and Alert System - Skin Protection

Featured Project

Team Members:

- Elizabeth Boehning (elb5)

- Gavin Chan (gavintc2)

- Jimmy Huh (yeaho2)

# Problem

Too much sun exposure can lead to sunburn and an increased risk of skin cancer. Without active and mindful monitoring, it can be difficult to tell how much sun exposure one is getting and when one needs to seek protection from the sun, such as applying sunscreen or getting into shady areas. This is even more of an issue for those with fair skin, but also can be applicable to prevent skin damage for everyone, specifically for those who spend a lot of time outside for work (construction) or leisure activities (runners, outdoor athletes).

# Solution

Our solution is to create a wristband that tracks UV exposure and alerts the user to reapply sunscreen or seek shade to prevent skin damage. By creating a device that tracks intensity and exposure to harmful UV light from the sun, the user can limit their time in the sun (especially during periods of increased UV exposure) and apply sunscreen or seek shade when necessary, without the need of manually tracking how long the user is exposed to sunlight. By doing so, the short-term risk of sunburn and long-term risk of skin cancer is decreased.

The sensors/wristbands that we have seen only provide feedback in the sense of color changing once a certain exposure limit has been reached. For our device, we would like to also input user feedback to actively alert the user repeatedly to ensure safe extended sun exposure.

# Solution Components

## Subsystem 1 - Sensor Interface

This subsystem contains the UV sensors. There are two types of UV wavelengths that are damaging to human skin and reach the surface of Earth: UV-A and UV-B. Therefore, this subsystem will contain two sensors to measure each of those wavelengths and output a voltage for the MCU subsystem to interpret as energy intensity. The following sensors will be used:

- GUVA-T21GH - https://www.digikey.com/en/products/detail/genicom-co-ltd/GUVA-T21GH/10474931

- GUVB-T21GH - https://www.digikey.com/en/products/detail/genicom-co-ltd/GUVB-T21GH/10474933

## Subsystem 2 - MCU

This subsystem will include a microcontroller for controlling the device. It will take input from the sensor interface, interpret the input as energy intensity, and track how long the sensor is exposed to UV. When applicable, the MCU will output signals to the User Interface subsystem to notify the user to take action for sun exposure and will input signals from the User Interface subsystem if the user has put on sunscreen.

## Subsystem 3 - Power

This subsystem will provide power to the system through a rechargeable, lithium-ion battery, and a switching boost converter for the rest of the system. This section will require some consultation to ensure the best choice is made for our device.

## Subsystem 4 - User Interface

This subsystem will provide feedback to the user and accept feedback from the user. Once the user has been exposed to significant UV light, this subsystem will use a vibration motor to vibrate and notify the user to put on more sunscreen or get into the shade. Once they have done so, they can press a button to notify the system that they have put on more sunscreen, which will be sent as an output to the MCU subsystem.

We are looking into using one of the following vibration motors:

- TEK002 - https://www.digikey.com/en/products/detail/sparkfun-electronics/DEV-11008/5768371

- DEV-11008 - https://www.digikey.com/en/products/detail/pimoroni-ltd/TEK002/7933302

# Criterion For Success

- Last at least 16 hours on battery power

- Accurately measures amount of time and intensity of harmful UV light

- Notifies user of sustained UV exposure (vibration motor) and resets exposure timer if more sunscreen is applied (button is pressed)