MEC202

Project Background and Objectives

Background: In modern society, people have a fast pace of life and high pressure, and they are unable to take care of plants and lack emotional sustenance. At the same time, existing intelligent plant products have certain advantages but still need improvement.

Objectives: By integrating a variety of sensors and intelligent control modules, ordinary plants are transformed into digital companions that can interact and communicate with users in real time, meeting users’ needs for convenient plant care, emotional interaction, and health monitoring.

Design Concepts and Screening

User Needs Survey: A questionnaire survey was conducted among about 30 people. The results show that users expect intelligent plants to have functions such as voice interaction and automatic watering, and they also hope to monitor the plant status through mobile phones and have healthy monitoring and friendly interactions with plants.

Function Design

Voice Response Function: Integrate a voice module so that the plant can respond with a friendly voice according to the user’s touch or distance, enhancing the emotional connection.

Touch Function: Use capacitive sensors to achieve feedback when the user touches the plant, such as expressing comfort or reminding not to touch too much.

Display Function: Use an OLED display to show rich visual effects, such as expression changes and information such as time and temperature.

Light Detection Function: Use a light sensor to sense the ambient light intensity, judge the time and adjust the behavior accordingly, such as reminding of dawn during the day and saying good night at night.

Automatic Watering Function: Use a soil moisture sensor to monitor the soil moisture and automatically start the water pump to water when it is dry. Different watering times can be set for different plants.

Monitoring Function: Use an ultrasonic sensor to monitor the distance between the user and the plant and remind the user to avoid sitting for a long time, promoting a healthy lifestyle.

Clock, Temperature and Humidity Display Function: Display the time, ambient temperature and soil humidity in real time to facilitate users’ understanding of the plant growth environment.

WIFI Function: Realize the connection between the plant and the Internet, and users can remotely monitor the plant status through the mobile app.

Prototyping and Testing

Prototype Building

Hardware Assembly: Use the STM32 microcontroller as the core, connect a variety of sensors such as WIFI, light, and soil moisture and related function modules to complete the basic framework of the system. The circuit design and function implementation principles of each module are introduced in detail, such as the reset circuit, boot circuit, and clock circuit.

Function Module Implementation: The voice command player communicates with the speaker through the UART port and plays voice; the touch sensor uses a capacitive sensor to solve the problem of false touch; the screen display module uses an OLED display to show rich information; the photoresistor and other sensors (such as temperature and humidity sensors, ultrasonic sensors, etc.) achieve corresponding functions according to their respective principles; the automatic watering system controls the water pump operation according to the soil moisture sensor data; the time module combines GPS and DS3231 chips to provide accurate time information; the WIFI module realizes data transmission and interaction with the mobile app.

Test Results

Ultrasonic Ranging Module: The recognition accuracy in some distance tests needs to be improved, but the health monitoring reminder function is normal.

Touch Sensor: The detection success rate reaches 98%, and the face-touch feedback function can be effectively realized.

Automatic Watering System: The overall performance is good, and it can water accurately according to the soil moisture. However, there were initial sensor calibration problems, which were improved after adjustment.

Clock Module: The time accuracy is high, with a daily deviation of less than 0.2 seconds, and the power consumption is low.

WIFI Module: It can effectively realize the connection and data transmission with the mobile phone and provide reliable wireless connection.

User Experience Feedback: Users appreciate the product functions such as automatic watering and health monitoring, but also put forward some suggestions for improvement, such as adding solar panels and super capacitors to solve the battery life problem, considering adding nutrient supplement functions, improving water resistance and perfecting functions.

Reflection and Improvement: Problems such as screen wiring errors were encountered during the product production process and were solved in time. In response to the problems in the test, it is planned to integrate more advanced algorithms to improve the accuracy of ultrasonic sensors and integrate the device into the Internet of Things framework.