Project

# Title Team Members TA Documents Sponsor
44 Self Temperature and Taste Regulating Tea Cup
Anirudh Kumar
James Li
Lahiru Periyannan
Rui Gong design_document1.pdf
final_paper1.pdf
photo1.jpg
photo2.jpg
photo3.jpg
photo4.jpg
presentation1.pdf
proposal1.pdf
proposal2.pdf
video
Team Members:
- zyli2
- lahirup2
- kumar67

# Problem

Current methods to brew tea lack ways to handle different tea leaves and maintain temperature. For instance, tea is usually brewed by adding boiling water to a cup of tea leaves. This is effective for tea leaves like black tea, however, for more delicate teas like green tea, this would bring out more bitterness as it burns the green leaves. Adding boiling 100°C water is way over green tea's preferred temperature range of 70-80°C. Temperature is important in brewing tea because different tea leaves require different temperatures to effectively bring out its aromatic compounds. The ability to heat different tea leaves to its optimal temperature and maintain its warmness would provide the best possible tea drinking experience.

# Solution

We propose a cup that can heat liquid optimal to the type of tea leaf chosen and maintain the liquid to a user-specified temperature. Our system provides a precise temperature control to combat inconsistencies in conventional tea brewing methods. Our cup integrates multiple subsystems to ensure optimal flavor extraction, temperature retention, and ease of use:

1) Sensors: detects and monitor tea temperature and tea bitterness

2) Heating and stirring: maintain uniform temperature and tea taste consistency

3) Power: power source to support other subsystems like heating, sensors, etc

4) Control and communication: receives commands from mobile app and collects data from sensors and transfers to mobile app

5) Mobile app/User interface: displays temperature and tea information

6) Cup: holds liquid for drinking

# Solution Component

## Subsystem 1: Sensors

Sensors are needed for many functionalities in this project. We of course need to monitor the temperature of the liquid within the cup. Given that our project will be working with mostly water and water - based tea, Campbell Scientific’s specialized sensors for water such as TempVue 50 could be useful here. We also need a way to determine how strong a liquid, such as tea, is. This can be done through a Total Dissolved Solids sensor, such as Seeed Studio’s Grove sensor.

## Subsystem 2: Heating and Stirring

These are two features of our project which are of course very important for people who drink tea. The tea needs to be maintained at the user's desired temperature, as having to reheat it can affect the flavor. To maintain temperature, a thermoelectric Peltier Module (PM) can be used; specifically, TEC1-07103 or similar, depending on the size of cup and desired efficiency. As for stirring, we can use N20 Micro Gear Motor mounted on the top of the cup, with an appendage to stir the liquid inside.

## Subsystem 3: Power
To power the Peltier module and stirrer, while maintaining portability, the cup will need to be battery-powered. A lithium-ion battery can be used, although bench power supply can be used initially and during early stages. In order to dynamically utilize the PM, which is dependent on input voltage to set the level of heating, a DC-DC Buck-Boost converter/regulator is needed. One potential unit is TPS63070/XL63070, which has a maximum output of 9V (The PM has a maximum rated voltage of 8.5V, so this minimizes potential overvoltage issues of other converter models). A switch is also needed to cut power to the device when necessary; the TPS63070 has built-in functionality to shut off output power while connected to the input.

## Subsystem 4: Control and Communication

We can use a microcontroller such as ESP32-S3-WROOM to collect the data from the sensors and communicate it to the mobile app / user interface (Subsystem 5). It will also be able to receive information (user settings) from the mobile application and then control the other subsystems as and when needed. It should monitor temperature and TDS regularly, perhaps every thirty seconds or even more frequently. Stirring will also be controlled by this subsystem and done at a regular interval as well.

## Subsystem 5: Mobile App / User Interface

We can either have a mobile app or a web app. Either way, it will display temperature and TDS readings to the user, as well as allow them to control both those values. It should also alert the user when their tea has reached the desired strength or temperature and allow them to provide settings for stirring. This app will communicate with the microcontroller from Subsystem 4 via Bluetooth / Wi-Fi.

## Subsystem 6: Cup

In order to best conduct heat from the Peltier module to the liquid, a layer of metal, such as aluminum is necessary on the bottom of the cup. Other than that point of contact, the rest of the cup may be made from ceramic, double-walled steel, or another similarly insulating material.

# Criterion For Success

- There should be accurate temperature control, within the range of a couple of degrees Celsius of the desired temperature.

- There should be accurate measurement of the strength of the tea via the TDS sensor. We will need to correlate TDS readings to categorical strength values (e.g. ‘weak’ or ‘strong’) as most people will not read a TDS reading and know what it means in terms of strength.

- The cup needs to be washable, so all the electronics should be waterproof.

- The mobile / web application for the user should be easy to use and clearly communicate all the necessary information.

Schnorr Protocol Key Fob

Michael Gamota, Vasav Nair, Pedro Ocampo

Featured Project

# Schnorr Identification Protocol Key Fob

Team Members:

- Michael Gamota (mgamota2)

- Vasav Nair (vasavbn2)

- Pedro Ocampo (pocamp3)

# Problem

Current car fobs are susceptible to different types of attacks. Rolling jam attacks are one of such attacks where an attacker jams and stores a valid "unlock" signal for later. Cars with passive keys/cards can be stolen using relay attacks. Since a car can be the most expensive item someone owns, it is unreasonable to allow people to steal them so discreetly by hacking the fob/lock combo.

# Solution

By leveraging public key cryptography, specifically the Schnorr identification protocol, it is possible to create a key fob which is not susceptible to either attack (rolling jam and relay) and also gives no information about the private key of the fob if the signal were to be intercepted.

# Solution Components

# Key Fob

## Subsystem 1

Random number generation - We will use a transistor circuit to generate random numbers. This is required by the Schnorr protocol to ensure security.

## Subsystem 2

Microcontroller - The MCU will run all the computation to calculate the messages. We will likely use an ATtiny MCU so we can use the Arduino IDE for programming. However, some group members have experience with the STM32 family so that is another option.

## Subsystem 3

Power - We plan on using either a 5V battery or 3.3V battery with a boost converter to power the fob.

## Subsystem 4

Wireless Communication - We plan on using the 315 MHz frequency band which is currently used by some car fobs. We will need a transmitter and receiver, since the protocol is interactive.

# Lock

## Subsystem 1

Random number generation - We will use a transistor circuit to generate random numbers. This is required by the Schnorr protocol to ensure security.

## Subsystem 2

Microcontroller - This MCU will also run all the computation to calculate the messages. We will likely use an ATtiny MCU so we can use the Arduino IDE for programming. However, some group members have experience with the STM32 family so that is another option. This MCU will need to have PWM output to control the lock.

## Subsystem 3

Linear Actuator - We plan on using a linear actuator as a deadbolt lock for demonstration purposes.

## Subsystem 4

Wireless Communication - We plan on using the 315 MHz frequency band which is currently used by some car fobs. We will need a transmitter and receiver, since the protocol is interactive.

## Subsystem 5

Power - This subsystem will also likely require 5V, but power sourcing is not an issue since this system would be connected to the car battery. During a demo I would be acceptable to have this plugged into a power supply or a barrel jack connector from an AC-DC converter.

# Criterion For Success

Describe high-level goals that your project needs to achieve to be effective. These goals need to be clearly testable and not subjective.

Our first criteria for success is a reasonably sized fob. There is some concern about the power storage and consumption of the fob.

The next criteria for success is communication between the fob and the lock. This will be the first milestone in our design. We will need to have a message sent from one MCU that is properly received by the other, we can determine this in the debug terminal.

Once we are sure that we can communicate between the fob and the lock, we will implement the Schnorr protocol on the two systems, where the fob will act as the prover and the lock as the verifier. If the Schnorr signature implementation is correct, then we will always be able to unlock the lock using the fob whose public key is associated with full privileges.

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