In our ever-evolving tech landscape, the ability to seamlessly integrate and configure Internet of Things (IoT) devices is crucial. Recently, I completed an exciting project where I leveraged React Native and Expo to build a mobile app that simplifies configuring IoT devices via Bluetooth Low Energy (BLE). In this blog post, I'll walk you through the key features of the project and the challenges we faced and overcame.

Project Overview The core objective of this project was to create a mobile application that enables users to configure IoT devices using BLE. The app allows users to set up WiFi and MQTT broker configurations for their devices, providing a streamlined and intuitive experience.

Key Features BLE Device Scanning and Connection

The app employs the react-native-ble-plx library to manage BLE operations. Users can scan for BLE devices and connect to a specific device identified by its name, which is derived from the last four digits of the device's WiFi MAC address. Once connected, the app discovers the device's services and characteristics.

WiFi Configuration

Users can configure WiFi settings for their IoT devices through the app. The configuration process involves sending the WiFi SSID and password to the device using a specific BLE service and characteristic. This ensures that the device can connect to the correct network.

MQTT Broker Configuration

Similarly, users can set up MQTT broker settings, which are crucial for devices that communicate via MQTT. The app sends the broker URL, IP address, and port to the device. This is accomplished using a dedicated BLE service and characteristic for MQTT settings.

User Interface and Workflow

The app features a clean and straightforward interface with distinct steps for configuring WiFi, MQTT, and adding the device. The user flow is designed to be intuitive, guiding users through each step with clear prompts and feedback.

Error Handling and Notifications

Effective error handling and user notifications are integral to the app's reliability. Users receive alerts and toast messages for various states, including scanning errors, connection issues, and successful configuration updates.

Technical Implementation BLE Integration

We used the react-native-ble-plx library to handle BLE operations, including scanning for devices, connecting, and reading/writing characteristics. This library provides a robust and flexible interface for interacting with BLE peripherals.

State Management

The app uses React's state management to handle device data, configuration forms, and UI states. The useState and useEffect hooks are employed to manage component states and side effects, such as starting and stopping BLE scans.

UI Components

The UI is built using React Native components and styled with StyleSheet. We created reusable components for buttons and modals, ensuring a consistent and user-friendly design throughout the app.

Error Handling and Alerts

Alerts and toast messages are used to provide feedback to users. This helps in informing them about connection statuses, configuration successes, or any issues encountered during the process.

Challenges and Solutions BLE Permissions

One of the challenges was managing BLE permissions across different platforms. We implemented a permissions check and prompt users to grant necessary access before starting BLE operations.

Device Discovery

Ensuring accurate device discovery and connection required handling various BLE events and filtering devices based on their names. We fine-tuned the scanning process and connection logic to enhance reliability.

Configuration Data

Encoding and decoding configuration data for BLE communication involved working with base64 encoding to ensure data integrity. We implemented robust data handling to ensure configurations are correctly formatted and transmitted.

Conclusion This project showcases the power of React Native and Expo in developing robust mobile applications for IoT device management. By integrating BLE for device configuration, we’ve streamlined the process of setting up devices and enhanced user experience. I hope this post provides valuable insights into the development process and encourages others to explore similar projects.