Project

# Title Team Members TA Documents Sponsor
6 Interactive Desktop Companion Robot for Stress Relief
Jiajun Gao
Yu-Chen Shih
Zichao Wang
Haocheng Bill Yang design_document1.pdf
proposal1.pdf
# Team
- Jiajun Gao (jiajung3)
- Yuchen Shih (ycshih2)
- Zichao Wang (zichao3)
# Problem
Students and office workers often spend extended periods working at desks, leading to mental fatigue, stress, and reduced focus. While mobile applications, videos, or music can provide temporary relief, they often require users to shift attention away from their primary tasks and lack a sense of physical presence. Static desk toys also fail to maintain long-term engagement because they do not adapt to user behavior or provide meaningful interaction.
There is a need for an interactive, physically present system that can provide short, low-effort interactions to help users relax without becoming a major distraction. Such a system should be compact, safe for desk use, and capable of responding naturally to user input.

# Solution
We propose an interactive desktop companion robot designed to reduce stress and boredom through voice interaction, expressive feedback, and simple physical motion. The robot has a compact, box-shaped form factor suitable for desk environments and can move using a tracked or differential-drive base. An ESP32-based controller coordinates audio processing, networking, control logic, and hardware interfaces.
The robot supports voice wake-up, natural language conversation using a cloud-based language model, and speech synthesis for verbal responses. Visual expressions are displayed using a small screen or LED indicators to reflect internal states such as listening, thinking, or speaking. Spoken commands can also trigger physical actions, such as rotating, moving closer, or changing expressions. By combining audio, visual, and physical interaction, the system creates an engaging yet lightweight companion that fits naturally into a desk workflow.
# Solution Components
## Subsystem 1: Voice Interaction and Audio Processing
This subsystem enables natural voice-based interaction between the user and the robot. It performs wake-word detection locally and streams audio data to a remote server for speech recognition and response generation. The subsystem also handles audio playback and interruption control.
Audio data is captured using a digital microphone, encoded, and transmitted over a network connection. Responses from the server are received as audio streams and played through an onboard speaker. Local wake-word detection ensures responsiveness and reduces unnecessary network usage.
Components:

• ESP32-S3 microcontroller with PSRAM
• ESP32-S3 integrated Wi-Fi module
• I2S digital microphone (INMP441 or equivalent)
• I2S audio amplifier (MAX98357A)
• 4Ω or 8Ω speaker
## Subsystem 2: Visual Expression and User Feedback
This subsystem provides visual feedback that represents the robot’s internal state and interaction context. Visual cues improve usability and convey personality.
Different states such as idle, listening, processing, speaking, and error are represented using animations or color patterns.
Components:

• SPI LCD display (ST7789 or equivalent) or
• RGB LEDs (WS2812B or equivalent)

## Subsystem 3: Motion and Actuation
This subsystem enables controlled movement on a desk surface. The robot performs simple motions such as forward movement, rotation, and stopping based on voice commands and sensor feedback.
Motor control runs in a dedicated task to prevent interference with audio and networking functions.
Components:

• Two DC gear motors
• Dual H-bridge motor driver (TB6612FNG or equivalent)
• Optional wheel encoders


## Subsystem 4: Power Management and Safety
This subsystem manages power distribution and ensures safe operation. The robot is battery-powered to allow untethered use on a desk. Hardware and software protections limit speed, current, and movement range.
Components:

• Lithium battery with protection circuit
• Battery charging module
• Voltage regulators (5V and 3.3V)
• Physical power switch

## Subsystem 5: Subsystem 5: Safety Sensing (Desk-Edge Detection + Obstacle Avoidance)

This subsystem prevents the robot from falling off the desk and reduces collisions with nearby objects. It continuously monitors both the surface below the robot and the space in front of the robot. When a desk edge (cliff) or obstacle is detected, this subsystem overrides motion commands and triggers an immediate safe response.

Desk-edge detection (cliff detection):
Two downward-facing distance sensors are mounted near the front-left and front-right corners. They measure the distance from the robot to the desk surface. If either sensor detects a sudden increase in distance beyond a calibrated baseline, the robot immediately stops and performs a short reverse maneuver to move away from the edge.

Obstacle avoidance:
A forward-facing distance sensor detects objects in front of the robot. If an obstacle is within a predefined safety distance, the robot stops. If the obstacle remains, the robot can optionally rotate in place to search for a clear direction before continuing motion.

Control priority:
Safety sensing has the highest priority in the motion stack:

Desk-edge detection (highest priority)

Obstacle avoidance

User/voice motion commands (lowest priority)

Components:

2 × Time-of-Flight distance sensors for downward cliff detection (VL53L0X or equivalent, I2C)

1 × Time-of-Flight distance sensor for forward obstacle detection (VL53L0X or equivalent, I2C)

# Criterion For Success
The success of this project will be evaluated using the following high-level criteria:
1. The robot connects to a Wi-Fi network and establishes a server connection within 10 seconds of power-on.
2. The system detects a wake word and enters interaction mode within 2 second in a quiet environment.
3. The average end-to-end voice interaction latency is less than 5 seconds under normal network conditions.
4. At least five predefined voice commands trigger the correct robot actions with at least 90% accuracy during testing.
5. Visual feedback correctly reflects the system state in all operational modes.
6. The robot operates continuously for at least 30 minutes on battery power during active use.
7. When Wi-Fi is unavailable, the system enters a safe degraded mode without crashing or unsafe motion.
8. During a 10-minute continuous motion demonstration on a desk, the robot does not fall off the desk.
9. In an obstacle test, the robot is commanded to move forward toward a stationary obstacle (for example, a box or book) from multiple start distances for 20 trials. The robot must stop (or stop and turn) before making contact in at least 18/20 trials.

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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