Project

# Title Team Members TA Documents Sponsor
28 "Don't Kill My Plant" Habit Tracker
Ben Wei
DK Ehiribe
Zade Lobo
Selva Subramaniam design_document1.pdf
final_paper1.pdf
photo1.jpg
photo2.jpg
photo3.jpeg
presentation1.pdf
proposal1.pdf
# "Don't Kill My Plant" Habit Tracker

Team Members:
- Zade Lobo (zlobo3)
- Ben Wei (btwei2)
- Dike Ehiribe (ehiribe2)

# Problem

We are trying to solve a problem that has plagued people for ages: breaking bad habits and adopting good ones. Even though humans may want to change these habits, they usually lack the willpower in order to do so.

Common solutions on the market to help people change habits include smartphone tracking apps and physical devices that track physical habits. These solutions are great for tracking, but the
There are plenty of apps and devices that help people with habit tracking, but most of them can be circumvented easily and don't hold people accountable for their actions. In addition, any positive reinforcement methods that they provide are minor and are not effective enough.

# Solution

We want to change this by bringing in emotional attachment to tangible consequences to encourage people to keep up with their habits. While positive reinforcement may not be as effective, negative punishment has also shown promising results.

"Don't Kill My Plant" is an application interface that will keep track of your habits through unforgeable data and will make the life of your plant dependent on it through hardware.

The solution we are providing is innovative by causing people to emotionally attach themselves to keeping up with good habits as well as keeping a physical and visual reminder.


# Solution Components

## Application Interface Subsystem

The application interface is a phone application that will offer multiple ways to track habit forming, including location, screentime, and message and call tracking. This allows the application to pick up on habits such as going to the gym, avoiding a coffee shop, spending too much time on social media, or messaging your family.

## Plant Enclosure Subsystem

The plant enclosure is a box with an airtight lid in order to create an isolated environment for a plant. The box itself will contain transparent walls with a method for blocking light out (either electronic tint or rolling window shades. The box will have an airtight lid that can be electronically opened and closed by the microcontroller.

## Microcontroller Subsystem

The microcontroller will be an ESP32 or ESP8266 that will pull from a server that the application interface is publishing to. This will determine the binary state of the plant enclosure system (killing or living). When the state on the server changes, then the microcontroller will control the plant enclosure subsystem to change the state of the box. The microcontroller will also allow routine watering of the plant through the irrigation system, which may be interrupted by not keeping up with habits.

## Irrigation Subsystem

The irrigation subsystem will be controlled by the microcontroller in order to routinely water the plant through the included water solenoid. The reservoir outside the plant enclosure will allow the user to input water for irrigation, but the actual water delivery will be controlled through hydraulic tubing piping it inside the system.

# Criteria For Success

- The created device system is capable of keeping a potted plant alive.
- The same device system also has the capability of killing a potted plant.
- The device can pull information from a server on habit uptime and determine the fate of the plant.
- The application interface is able to facilitate habit tracking for the user and send this information to a server.

Four Point Probe

Simon Danthinne, Ming-Yan Hsiao, Dorian Tricaud

Four Point Probe

Featured Project

# Four Point Probe

Team Members:

Simon Danthinne(simoned2)

Ming-Yan Hsiao(myhsiao2)

Dorian Tricaud (tricaud2)

# Problem:

In the manufacturing process of semiconductor wafers, numerous pieces of test equipment are essential to verify that each manufacturing step has been correctly executed. This requirement significantly raises the cost barrier for entering semiconductor manufacturing, making it challenging for students and hobbyists to gain practical experience. To address this issue, we propose developing an all-in-one four-point probe setup. This device will enable users to measure the surface resistivity of a wafer, a critical parameter that can provide insights into various properties of the wafer, such as its doping level. By offering a more accessible and cost-effective solution, we aim to lower the entry barriers and facilitate hands-on learning and experimentation in semiconductor manufacturing.

# Solution:

Our design will use an off-the-shelf four point probe head for the precision manufacturing tolerances which will be used for contact with the wafer. This wafer contact solution will then be connected to a current source precisely controlled by an IC as well as an ADC to measure the voltage. For user interface, we will have an array of buttons for user input as well as an LCD screen to provide measurement readout and parameter setup regarding wafer information. This will allow us to make better approximations for the wafer based on size and doping type.

# Solution Components:

## Subsystem 1: Measurement system

We will utilize a four-point probe head (HPS2523) with 2mm diameter gold tips to measure the sheet resistance of the silicon wafer. A DC voltage regulator (DIO6905CSH3) will be employed to force current through the two outer tips, while a 24-bit ADC (MCP3561RT-E/ST) will measure the voltage across the two inner tips, with expected measurements in the millivolt range and current operation lasting several milliseconds. Additionally, we plan to use an AC voltage regulator (TPS79633QDCQRQ1) to transiently sweep the outer tips to measure capacitances between them, which will help determine the dopants present. To accurately measure the low voltages, we will amplify the signal using an JFET op-amp (OPA140AIDGKR) to ensure it falls within the ADC’s specifications. Using these measurements, we can apply formulas with corrections for real-world factors to calculate the sheet resistance and other parameters of the wafer.

## Subsystem 2: User Input

To enable users to interact effectively with the measurement system, we will implement an array of buttons that offer various functions such as calibration, measurement setup, and measurement polling. This interface will let users configure the measurement system to ensure that the approximations are suitable for the specific properties of the wafer. The button interface will provide users with the ability to initiate calibration routines to ensure accuracy and reliability, and set up measurements by defining parameters like type, range, and size tailored to the wafer’s characteristics. Additionally, users can poll measurements to start, stop, and monitor ongoing measurements, allowing for real-time adjustments and data collection. The interface also allows users to make approximations regarding other wafer properties so the user can quickly find out more information on their wafer. This comprehensive button interface will make the measurement system user-friendly and adaptable, ensuring precise and efficient measurements tailored to the specific needs of each wafer.

## Subsystem 3: Display

To provide output to users, we will utilize a monochrome 2.4 inch 128x64 OLED LCD display driven over SPI from the MCU. This display will not only present data clearly but also serve as an interface for users to interact with the device. The monochrome LCD will be instrumental in displaying measurement results, system status, and other relevant information in a straightforward and easy-to-read format. Additionally, it will facilitate user interaction by providing visual feedback during calibration, measurement setup, and polling processes. This ensures that users can efficiently navigate and operate the device, making the overall experience intuitive and user-friendly.

# Criterion for Success:

A precise constant current can be run through the wafer for various samples

Measurement system can identify voltage (10mV range minimum) across wafer

Measurement data and calculations can be viewed on LCD

Button inputs allow us to navigate and setup measurement parameters

Total part cost per unit must be less than cheapest readily available four point probes (≤ 650 USD)

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