Monitoring System for Office Plant Care

Solution

The system developed by the Integra team is similar to a smart home setup but focused specifically on plant watering. Its key components include:

• Sensors for monitoring soil parameters
• A gateway (hub) for collecting and transmitting data to the server
• A web application for server management
• A mobile app for end users

The battery-powered sensors are inserted into the soil. They collect data and transmit it via Zigbee to the gateway. The choice of Zigbee was driven by its mesh network topology. Zigbee devices can relay data through neighboring nodes that act as repeaters. In large commercial spaces with numerous walls and partitions, this makes it possible to cover vast areas simply by adding more sensors. Zigbee networks can support up to 250 nodes, which is essential for shopping centers and large office buildings.

The gateway functions as a router, forwarding data from the sensors to the server. It uses the ESP32-S3 SoC, which supports both BLE for communicating with sensors via Zigbee and Wi-Fi for internet connectivity. The gateway periodically polls the sensors for readings and transmits the collected data to the server using the MQTT protocol.

The server aggregates the data in a database, which stores information about all plants registered in the system, their watering history, and related parameters. These records are also used for analytics to calculate how quickly the soil dries, the temperature patterns maintained in the room, and other environmental insights. End users can either install the server application on their own server or use the cloud-based version.

Our team developed a dedicated mobile application for employees responsible for watering. It allows them to register in the system and view their assigned schedule. At the configured time, the server sends a push notification reminding the user that it’s their turn to water the plants. To record the watering event in the database, the employee simply scans the plant’s QR code in the app and confirms the action with one tap.

The mobile app can also work in the administrator mode that allows users to interact with the server. The admin can add new plants to the database, assign or remove users responsible for watering, and create watering schedules. The same interface can generate unique QR codes for each plant, which can then be printed for quick and easy identification.

This functionality is also available through a separate web application designed for users who prefer working from a personal computer.

If the system detects that the soil moisture level in a specific pot is too low—whether due to the plant’s characteristics, microclimate peculiarities, or simply because an employee neglected their duty—the application sends an additional push notification to alert the user and prompt timely care for that plant.

App Development with Flutter

The project scope included developing a mobile user application for Android and iOS, as well as a web application for server management. We used Flutter as our primary tool. Flutter is a cross-platform framework that offers several distinct advantages over alternatives, for instance the Qt framework.

Flutter significantly accelerates mobile development due to several key factors:

1) Flutter uses the Dart language. Unlike C++, which is used for developing application logic in Qt, Dart is a modern, object-oriented language with an intuitive syntax. It is more streamlined and requires significantly less boilerplate code.

2) In Qt, developers typically use C++ for application logic and QML for UI development. In Flutter, both the UI and logic are written in Dart. This eliminates the need to switch between languages, set up complex bindings, or write additional “service” code.

3) Flutter provides comprehensive UI libraries out of the box for both iOS and Android.

4) Cross-platform consistency in Flutter is achieved by running the application in the Dart Virtual Machine. This ensures the UI renders identically across all platforms.

5) The Hot Reload feature allows developers to apply code changes instantly without recompiling the entire app or losing the current app state (e.g., staying on the same sub-menu without re-logging). This dramatically speeds up the iteration process.

6) Flutter offers a vast array of pre-built packages that solve common mobile development problems, often encountered in Qt: managing user permissions, QR code scanning, push notifications, camera and biometrics integration, MQTT, NFC, and Bluetooth functions, and more.

To illustrate, implementing the QR code scanning feature for this project took only 4 hours. A similar feature on a different Qt-based project required over 14 hours. Setting up push notifications took 9 hours, whereas the same task in Qt can exceed 50 hours. In both instances, Qt development takes longer because of the lack of ready-made solutions, requiring existing libraries to be manually refined or rebuilt.

Qt remains an indispensable framework for embedded systems with “heavy” logic and limited hardware resources such as industrial solutions or medical equipment. But Flutter is the superior choice for developing consumer and commercial mobile and web applications.

Scope of Work

• Gateway design
• Custom firmware development
• Server application development
• Web application development
• Mobile application development

Technologies Used

• APM32F407VGT6 was used as the MCU for the gateway.
• Altium Designer was used for schematics and PCB layout design.
• The firmware was written in C++ using Qt.
• The server application was developed in Python.
• The web app and mobile app for iOS and Android were written in Dart using the Flutter framework.

Result 

The project has successfully progressed from an initial idea to a working prototype ready for demonstration and real-world use. Our team built a robust hardware and software system that shifts plant care from intuitive guesswork to data-driven decision-making.

Our solution made it possible to:

• Deliver a scalable system suitable for different types of enterprises, including business centers, coworking spaces, restaurants and cafes, spa complexes, small private clinics, showrooms, and more.
• Reduce development costs and speed up time-to-market by more than 100 hours thanks to using the Flutter framework for mobile and web applications.
• Improve service quality and the brand image: adopting an IoT-based solution in phytodesign reinforces the company’s technological profile and guarantees impeccable condition of green zones in interior spaces.
• Minimize end customers’ losses from plant deaths through automatic monitoring of soil moisture and other parameters, duty scheduling, and a system of push notifications.

The customer is currently testing the system. If the product proves to be in demand, they plan to extend its functionality, in particular by adding automated watering.