Unlocking Smart Recycling in 500 milliseconds

Connecting the mobile app to the smart bin was done via the MQTT protocol, enabling direct communication with the bin’s software controller. This was challenging because there is no traditional server; the app has to connect directly to the device.

The MQTT protocol enabled direct, low-latency communication between the app and the bin controller. Message topics and subscriptions were organized hierarchically, and messages were optimized in size and structure to ensure fast and reliable performance on resource-constrained embedded devices.

The development was done without access to a physical controller, as the bin had not yet been produced, making testing and simulating real-world behavior difficult. We had to create virtual environments and simulations to develop and test the features.

A simulation environment was built to replicate the bin controller’s behavior, allowing thorough testing and debugging before the hardware was available. Both normal operations and edge cases, such as network drops or simultaneous command requests, were simulated to ensure the app would function reliably once connected to the physical bins.

Each of the four bins needed to be opened individually via QR code or the app, requiring precise authentication and security management. The system had to prevent multiple bins from being opened at once while keeping the user experience simple and intuitive.

Each bin was assigned a unique QR code and identifier, integrated into the app’s authentication system. The system validates access individually, preventing users from opening multiple bins simultaneously, while providing immediate feedback to ensure a smooth and secure user experience.