Project

# Title Team Members TA Documents Sponsor
15 Auto adjusted lighting system for room
Howard Li
Jihyun Seo
Kevin Chen
Zhuoer Zhang design_document1.pdf
proposal1.pdf
**TITLE**

Auto-Adjusted Smart Lighting System for Healthy Indoor Environments

**TEAM MEMBERS:**

Howard Li [zl114]

Jihyun Seo [jihyun4]

Kevin Chen [kdchen2]

**PROBLEM**

Most people do not give much thought to the lighting conditions in the rooms where they spend hours working, studying, or relaxing. As a result, the lighting and brightness levels are often unsuitable for eye health and comfort. Poor or inconsistent lighting can lead to eye strain, headaches, fatigue, and reduced productivity.

While modern devices like phones and laptops already include adaptive brightness features, room lighting has largely remained static, requiring manual adjustment if at all. Sudden changes in light intensity can also be jarring, creating discomfort instead of solving the problem.
We aim to solve the problem of creating an automatic, health-conscious lighting system for indoor environments that adjusts brightness in real time based on sensed conditions and does so gradually to protect users’ eyes.

**SOLUTION**

Our solution is to build a system of multiple wireless sensors placed around a room to continuously measure light levels at different points. These sensors will connect to a central control unit, which processes the readings and determines the optimal lighting adjustments for the space.

The system will then control the room’s artificial lights, increasing or decreasing brightness to achieve a consistent, eye-healthy level across the room. Importantly, these adjustments will be gradual—mimicking the smooth transitions of a phone screen’s auto-brightness—so that users never experience sudden, distracting changes in illumination.

This approach introduces several subsystems:

Wireless sensing subsystem: distributed light sensors communicate readings to the main controller.
Central control subsystem: interprets sensor data and computes adjustments.
Lighting control subsystem: modifies the brightness and potentially the color temperature of the lights.

User comfort subsystem: ensures that changes are gradual and within recommended ranges for eye comfort.

In addition to improving eye comfort, our system will also focus on energy efficiency. By actively monitoring natural daylight levels through the sensors, the system can reduce or even turn off artificial lighting when sunlight provides sufficient brightness. This ensures that lights are only used when necessary, lowering energy consumption and utility costs while promoting sustainability.

**SOLUTION COMPONENTS**

SENSORS

We will use ambient light sensors to measure lux levels at multiple locations in the room. Placing sensors in different spots ensures accurate feedback even if natural light is unevenly distributed. These sensors will transmit data wirelessly to the central controller.

WIRELESS NETWORK & CENTRAL CONTROLLER

A controller will collect all sensor data, run algorithms to determine the target lighting level, and send control signals to smart drivers or dimmers. The wireless system allows easy deployment without additional wiring.

LIGHTING CONTROL

We will integrate dimmable LED lights or connect to existing lighting fixtures via smart dimmers. The control logic will avoid rapid brightness jumps by gradually adjusting output intensity. We may also explore adaptive color temperature to better mimic natural daylight cycles.

USER INTERFACE (OPTIONAL)

A controller or could allow users to set preferences, such as “focus mode,” “relax mode,” or “sleep preparation mode,” which would adjust the target brightness levels and transition speeds.

CRITERION FOR SUCCESS

The system must be able to detect ambient lighting conditions in multiple parts of the room and wirelessly send the data to the central unit.
The lights should respond automatically to sensor data without user intervention.
Brightness adjustments should be gradual, with no sudden jumps noticeable to the human eye.
The lighting should remain within healthy ranges recommended for eye comfort (e.g., 300–500 lux for reading, 100–200 lux for relaxation).
Optional success criteria: the user interface allows customization of lighting preferences.

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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