Project

# Title Team Members TA Documents Sponsor
46 Snooze-Cruiser
Alex Wang
Jiachen Hu
Jizhen Chen
Jiaming Xu
#Snooze-Cruiser
Team Members:

Jiachen Hu (hu86)

Jizhen Chen (jizhenc2)

Alex Wang (zw71)

#Problem

Many people suffer from sleep inertia, a condition where individuals instinctively silence alarms without fully waking up. Traditional alarm clocks and smartphone alarms rely solely on audio, which can be easily ignored or dismissed while half asleep. Existing alternative solutions such as puzzle-based alarms or flying alarms are often ineffective, unsafe, or impractical in confined environments like dorm rooms and bedrooms.

The fundamental issue is that current alarm systems fail to reliably force physical engagement, allowing users to return to sleep without becoming fully alert. A more effective alarm must require the user to physically interact with the system in order to disable it.

#Solution

We propose Snooze-Cruiser, a two-wheeled differential-drive robotic alarm system that physically moves away from the user when the alarm time is reached. Instead of simply producing sound, the robot navigates around the room, forcing the user to get out of bed and chase it in order to silence the alarm.

The robot operates autonomously in a confined indoor space, using onboard sensors for obstacle avoidance and odometry-based localization to remain within a defined area. The alarm is disabled not by pressing a button, but by detecting when the robot has been picked up using inertial sensor data. This interaction ensures that the user must physically wake up and engage with the device.

The system is divided into motion control, sensing, alarm/audio, localization, and power management subsystems.

#Solution Components

##Subsystem 1: Motion Control and Navigation

Function:
This subsystem enables the robot to move autonomously, wander unpredictably, and avoid obstacles while remaining within a confined area.

Components:

Microcontroller: STM32F446RCT6

Motor Driver: DRV8833PWP dual H-bridge motor driver

Motors: N20 micro gear motors with quadrature encoders (x2)

Inertial Measurement Unit: MPU6050

Obstacle Sensors: VL53L1X Time-of-Flight distance sensors (multiple)

Description:
The STM32 generates PWM signals to control the motors through the DRV8833 motor driver. Wheel encoders provide feedback for estimating speed and displacement. During alarm operation, the robot drives forward at a base speed and periodically introduces random heading changes. Obstacle avoidance is triggered when distance sensors detect nearby obstacles, causing the robot to turn away and resume wandering motion. Encoder and IMU data are fused to estimate the robot’s position relative to its starting point.

##Subsystem 2: Localization and Soft Geofencing

Function:
This subsystem prevents the robot from leaving the intended operating area (e.g., a bedroom).

Components:

Wheel Encoders (from Subsystem 1)

IMU: MPU6050

Description:
Wheel encoder data and IMU measurements are fused using a Kalman Filter (or equivalent sensor fusion approach) to estimate the robot’s displacement from its starting location. A soft geofence is defined as a radius around this starting point. If the robot exceeds this radius, it enters a return-to-center behavior by rotating toward the estimated origin and driving inward until it re-enters the allowed area.

##Subsystem 3: Alarm Timing and Audio Output

Function:
This subsystem handles timekeeping and audible alarm generation.

Components:

Microcontroller: STM32F446RCT6

Audio Amplifier: PAM8301AAF

Speaker

Description:
The STM32 maintains a real-time counter for alarm scheduling. When the preset alarm time is reached, the microcontroller simultaneously enables the audio amplifier and activates the motion subsystem. The alarm sound continues until a valid caught event is detected.

##Subsystem 4: Caught Detection (User Interaction)

Function:
This subsystem detects when the robot has been picked up by the user and disables the alarm.

Components:

IMU: MPU6050

Wheel Encoders

Description:
Caught detection is performed by analyzing IMU acceleration and vibration data in combination with wheel encoder feedback. A caught event is identified by sudden changes in acceleration magnitude, high-frequency vibrations from human handling, and inconsistencies between wheel motion and measured acceleration (indicating loss of ground contact). Once confirmed, the system immediately stops motor output and silences the alarm.

##Subsystem 5: Power Management

Function:
This subsystem supplies and regulates power for the robot.

Components:

Battery Charger IC: MCP73844

Rechargeable Battery

Voltage Regulation Circuitry

Description:
The battery supplies power to the MCU, sensors, motor driver, and audio system. The MCP73844 manages battery charging. Voltage regulation ensures stable operation during high current events such as motor startup.

#Criterion For Success

The project will be considered successful if the following objective criteria are met:

Timed Activation:
The alarm triggers within ±X seconds of the programmed time.

Synchronized Operation:
Robot motion and alarm audio start simultaneously upon alarm activation.

Autonomous Motion:
The robot moves continuously without user intervention during alarm operation.

Obstacle Avoidance:
The robot avoids obstacles placed in its path without repeated collisions.

Confined Operation:
The robot remains within a predefined operating radius and returns toward the starting location when the boundary is exceeded.

Caught Detection:
When picked up by a user, the robot reliably stops motion and audio within a short time window.

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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