Wearable Locator for Assisted Living
Wearable Locator Project Description
The wearable is a small locator beacon for assisted living residents that will assist in: Locating them within the facility, opening authorized doors using Bluetooth Low Energy technology, and provide a manual button that the resident can press that would indicate they need “non emergency” assistance. Once a resident presses the button on the locator beacon, it’ll will show their location on the property and text/email support staff to respond. The device is portable and has a long battery life. The goal of this project was to make the chipset small enough to fit in a simple wearable or perhaps even embedded in jewelry etc.
Fulfilling Our Customer Needs
The wearable device is designed to be both inexpensive and energy efficient. As a modular wearable that assisted living residents could use, we sought to make a device able to help staff locate users with minimal impacts on privacy and autonomy.
The Wearable
- Has the ability to open authorized doors through Bluetooth.
- Includes a non-emergency assistance button.
- Sends signals when active to track the user.
- Provides location sharing information to help track a user within
the grounds of a facility.
the grounds of a facility.
The Effects of COVID-19 on the Development of the Wearable Locator
COVID-19 had several significant impacts on the development of the wearable device. Our project development relied heavily on our hardware components, making it difficult to collaborate and develop functions with appropriate testing. As a result of travel restrictions, the hardware remained separated between a handful of the development team’s members. This left our team in a situation where we had to purchase more hardware and collaborate digitally. We decided to continue collaborating with open communication across teams, but the shipping times required to get our development kits into the hands of developers proved to be too long.
The quarantine was announced to resume through to the end of the Spring 2020 semester; high cost and low availability of development kits was an insurmountable obstacle. Development and testing required multiple devices to effectively test the program and simulate device communication. Developers without the hardware required were not able to run appropriate tests, inevitably forcing our teams to pressure developers that did have hardware. We are especially thankful for the patience and diligence that these team members have shown through the development of this project.
COVID-19 made acquiring the source code we needed from the sponsor more difficult as well. We needed proprietary code that would allow the wearable to interface with the locks, but the sponsor lost their contact as a result of the economic impacts of the virus. This forced Corserva to seek out a new company for the locks they wanted to use. Losing our lock contact resulted in the loss of one of the device’s core functionalities.
Design & Development Process
The first step of the development process was to choose the platform on which we would base our solution. As our device utilizes Bluetooth Low Energy as a primary feature, we looked for a System on a Chip (SoC) which combined a low power microcontroller with an integrated Bluetooth radio. We settled on the Nordic Semiconductor nRF52 series SoCs, in particular the nRF52811. This device combines a low power ARM Cortex-M4 processor with Bluetooth 5.2 support, and comes in packages with sizes ranging from 6x6mm down to an extremely small 2.5x2.5mm.
The powerful SDK for the nRF52 series and fully featured Bluetooth stack allowed us to quickly setup up an example program which demonstrated the use of a custom Bluetooth service. This service provided a single value which could be read from and written to using another Bluetooth enabled device.
Due to complications with access to production infrastructure that these devices would be used with, we resorted to developing simplified software which allowed us to mimic the interaction pattern between the wearable device and the facility server or door lock. From there, we could focus on the two core features of the wearable device: requesting assistance and opening doors. The following two videos demonstrate and explain the functionality of these features:
Example of assistance request functionality. The board on the right acts as the wearable device. When the button is pressed, it connects to the server (left) and the server acknowledges the assistance request. The console on the top shows the action log of the wearable device, while the bottom shows the log of the server.
Example of door lock functionality. When the button on the wearable device (right) is pressed, it connects to the door lock (left) and unlocks it. The console on the top shows the action log of the door lock, and the bottom one shows the log of the wearable device.
