TekBox Executive Project Summary

The store hours at the TekBots Store in the Kelley Engineering Center are limited by available student volunteer hours. Thus, a secure system for obtaining engineering kits is required to expand student accessibility. The TekBox, an Internet of Things (IoT) connected lockbox will help solve this problem. The development process was based on these requirements:

• Reconfigurability
• Security
• Ease of use
• Power efficiency

Additional engineering requirements were created based on the client’s needs:

• Multiple authenticated users can configure the system.
• The system status can be viewed remotely.
• The system must fit in an 8” by 8” area.
• The system must display the battery’s charge level up to ±5% accuracy.
• The system shall be rechargeable via an external source while operating.
• The system shall last up to 24 hours on battery power.
• The system shall have a quick connect option for wireless connectivity.
• The system must be configurable without the need to connect to a server.
• The system shall be unlockable by authenticated users without a server connection.
• The system shall connect to a user's device within 10 seconds of the user's request for a Bluetooth connection.
• The system shall accept and store conventional Wi-Fi credentials (including SSID, and password) during the setup process.
• The system shall unlock within 10 seconds of the user entering a disarm action and pressing the unlock button.

The team’s design process involved choosing an appropriate microcontroller, locking mechanism, battery, and software application programming interface (API) for administrative system configuration and the end-user application. Additional work on the project included design of a power distribution board and front panel for user interaction. The microcontroller chosen was the ESP32 with the alternative being a Raspberry Pi. A solenoid lock was chosen as the locking mechanism. A single-cell Lithium-Polymer (LiPo) battery was chosen as the main power source. A power distribution board was designed for 12V and 3.3V power rails, a 5V USB-C input for battery charging, and system power monitoring. The front panel was designed for a simple power readout, (un)lock status, (un)occupied status, and a single multi-use button. The backend software is built using PHP and MySQL, supporting system administration & customer pickup websites, and a mobile API. The native iOS app is written in Swift, providing locker setup and offline access.

The TekBox system currently supports connecting multiple lockers to a backend designed for use by OSU students and faculty. It requires extra power to operate the solenoid lock, and has a powered display that needs functionality added. The engineering requirements not tested are the battery charge level and system duration. This first prototype was a success but optimization is needed and more functionality can be added for further iterations.