MEC202

Project Background and Objectives

Background: With the development of smart homes, people’s demand for desk functions has increased, while the functions of existing desks are single. Through online searches and questionnaires, it was found that most users use desks for more than 4 hours a day and have high expectations for smart desks.

Objectives: Design a smart desk integrating multiple functions such as lamp brightness adjustment, computer status detection, appliance control, timing, automatic power-off, automatic charging, and sitting posture detection.

Planning and Division of Labor: The project is carried out in stages, including topic discussion, sensor purchase, structure and circuit construction, function implementation, testing and feedback, and adjustment and optimization. Team members have clear division of labor, each responsible for hardware design, code writing, function module implementation, report writing and other tasks.

Design Concepts

Ambient Brightness: Install a light strip on the top of the screen to achieve lighting coverage, and use an ultrasonic sensor combined with specific gestures or distance judgments to realize intelligent brightness adjustment.

Time Management: Set two timing modes: active and passive. The active timing is enabled and adjusted by a touch sensor, and the passive timing reminds once an hour.

Safety Consideration: Use Raspberry PI face recognition to determine whether the user has left, and disconnect the device through a docking station to achieve protection.

Health Problems: Select a combination of distance sensors and binocular cameras to monitor the distance between the user and the screen in real time and give sitting posture prompts.

Computer Problems: Use an HDMI cable to directly connect the computer information to the self-made display screen to achieve computer status monitoring.

Appliance Control: Use an infrared remote control module with a specific frequency to control household appliances and monitor the temperature and status of the appliances.

Charging Module: Use both a wired charging hub and a wireless magnetic absorption charging module to achieve charging functions.

Prototyping and Testing

Desk Model Construction: Select a log desktop and metal legs to make a desk prototype, determine the location of each function area and reserve space, and modify the desktop structure.

Hardware Prototype Implementation: Independently design UNO boards to control each function module. Introduce the sensors used such as DHT11 temperature and humidity sensors and infrared transceiver modules. Different UNO boards are responsible for controlling the display screen, timing, speech recognition, appliance control, charging and other functions. Complete the installation and packaging of each function area, and design the power supply logic and internal wiring.

Face Recognition Principle: Realize face recognition based on the dlib library, including steps such as collecting face data sets, calculating feature vectors, comparing Euclidean distances, etc. Set an appropriate threshold to judge whether it is the same person, and realize the communication between Arduino and Raspberry Pi.

Board-to-Board Communication: Considering the limitation of Arduino hardware serial ports, design UNO5 to send startup and shutdown messages to other boards to realize signal transmission and function control between boards. Detail the communication logic of functions such as active/passive timing, device protection, and sitting posture detection.

Testing and Analysis

Function Testing: Test each function of the smart desk, such as wireless charging, lighting adjustment, console control, display function, sensor function, health monitoring and device protection. The test results show that most functions are normal, but there are also some problems such as some mobile phones cannot be wirelessly charged and the touch sensor sometimes fails.

User Feedback: Invite 20 people, including students and faculty, to test. The overall satisfaction rate is over 85%. Users highly evaluate functions such as health monitoring and remote control, but also put forward improvement suggestions such as adding a smart chair, improving the sensitivity of light adjustment, and customizing passive timing.

Future Work: Plan to add a smart chair, replace the high-sensitivity light strip, improve the support structure of the desk, add a water cup spill-proof module and a voice recognition module.

Project Summary

The project completed the design and production of the smart desk, realized the expected functions, analyzed and adjusted according to user feedback. Team members’ abilities in sensor application, circuit construction, code writing and teamwork have been improved, and experience has been accumulated for future professional learning.d will need to continue to improve the technology.