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.

Monitor for Dough and Sourdough Starter

Jake Hayes, Abhitya Krishnaraj, Alec Thompson

Monitor for Dough and Sourdough Starter

Featured Project

Team Members:

- Jake Hayes (jhayes)

- Abhitya Krishnaraj (abhitya2)

- Alec Thompson (alect3)

# Problem

Making bread at home, especially sourdough, has become very popular because it is an affordable way to get fresh-baked bread that's free of preservatives and other ingredients that many people are not comfortable with. Sourdough also has other health benefits such as a lower glycemic index and greater bioavailability of nutrients.

However, the bulk fermentation process (letting the dough rise) can be tricky and requires a lot of attention, which leads to many people giving up on making sourdough. Ideally, the dough should be kept at around 80 degrees F, which is warmer than most people keep their homes, so many people try to find a warm place in their home such as in an oven with a light on; but it's hard to know if the dough is kept at a good temperature. Other steps need to be taken when the dough has risen enough, but rise time varies greatly, so you can't just set a timer; and if you wait too long the dough can start to shrink again. In the case of activating dehydrated sourdough starter, this rise and fall is normal and must happen several times; and its peak volume is what tells you when it's ready to use.

# Solution

Our solution is to design a device with a distance sensor (probably ultrasonic) and a temperature sensor that can be attached to the underside of most types of lids, probably with magnets. The sensors would be controlled with a microcontroller; and a display (probably LCD) would show the minimum, current, and maximum heights of the dough along with the temperature. This way the user can see at a glance how much the dough has risen, whether it has already peaked and started to shrink, and whether the temperature is acceptable or not. There is no need to remove it from its warm place and uncover it, introducing cold air; and there is no need to puncture it to measure its height or use some other awkward method.

The device would require a PCB, microcontroller, sensors, display, and maybe some type of wireless communication. Other features could be added, such as an audible alarm or a graph of dough height and/or temperature over time.

# Solution Components

## Height and Temperature Sensors

Sensors would be placed on the part of the device that attaches to the underside of a lid. A temperature sensor would measure the ambient temperature near the dough to ensure the dough is kept at an acceptable temperature. A proximity sensor or sensors would first measure the height of the container, then begin measuring the height of the dough periodically. If we can achieve acceptable accuracy with one distance sensor, that would be ideal; otherwise we could use 2-4 sensors.

Possible temperature sensor: [Texas Instruments LM61BIZ/LFT3](https://www.digikey.com/en/products/detail/texas-instruments/LM61BIZ%252FLFT3/12324753)

Proximity sensors could be ultrasonic, infrared LED, or VCSEL.\

Ultrasonic: [Adafruit ULTRASONIC SENSOR SONAR DISTANCE 3942](https://www.digikey.com/en/products/detail/adafruit-industries-llc/3942/9658069)\

IR LED: [Vishay VCNL3020-GS18](https://www.mouser.com/ProductDetail/Vishay-Semiconductors/VCNL3020-GS18?qs=5csRq1wdUj612SFHAvx1XQ%3D%3D)\

VCSEL: [Vishay VCNL36826S](https://www.mouser.com/ProductDetail/Vishay-Semiconductors/VCNL36826S?qs=d0WKAl%252BL4KbhexPI0ncp8A%3D%3D)

## MCU

An MCU reads data from the sensors and displays it in an easily understandable format on the LCD display. It also reads input from the user interface and adjusts the operation and/or output accordingly. For example, when the user presses the button to reset the minimum dough height, the MCU sends a signal to the proximity sensor to measure the distance, then the MCU reads the data, calculates the height, and makes the display show it as the minimum height.

Possible MCU: [STM32F303K8T6TR](https://www.mouser.com/ProductDetail/STMicroelectronics/STM32F303K8T6TR?qs=sPbYRqrBIVk%252Bs3Q4t9a02w%3D%3D)

## Digital Display

- A [4x16 Character LCD](https://newhavendisplay.com/4x16-character-lcd-stn-blue-display-with-white-side-backlight/) would attach to the top of the lid and display the lowest height, current height, maximum height, and temperature.

## User Interface

The UI would attach to the top of the lid and consist of a number of simple switches and push buttons to control the device. For example, a switch to turn the device on and off, a button to measure the height of the container, a button to reset the minimum dough height, etc.

Possible switch: [E-Switch RA1113112R](https://www.digikey.com/en/products/detail/e-switch/RA1113112R/3778055)\

Possible button: [CUI Devices TS02-66-50-BK-160-LCR-D](https://www.digikey.com/en/products/detail/cui-devices/TS02-66-50-BK-160-LCR-D/15634352)

## Power

- Rechargeable Lithium Ion battery capable of staying on for a few rounds of dough ([2000 mAh](https://www.microcenter.com/product/503621/Lithium_Ion_Battery_-_37v_2000mAh) or more) along with a USB charging port and the necessary circuitry to charge the battery. The two halves of the device (top and underside of lid) would probably be wired together to share power and send and receive data.

## (stretch goal) Wireless Notification System

- Push notifications to a user’s phone whenever the dough has peaked. This would likely be an add-on achieved with a Raspberry Pi Zero, Gotify, and Tailscale.

# Criterion For Success

- Charge the battery and operate on battery power for at least 10 hours, but ideally a few days for wider use cases and convenience.

- Accurately read (within a centimeter) and store distance values, convert distance to dough height, and display the minimum, maximum, and current height values on a display.

- Accurately read and report the temperature to the display.

- (stretch goal) Inform the user when the dough has peaked (visual, audio, or app based).

Project Videos