About smartCharms

smartCharms is a prototype for a modular smart bracelet designed specifically for elderly people. It is made of squishy silicone beads, each set to have different functions. Its primary use is to keep the wearer safe by detecting falls and allowing the wearer to call for help by pressing a button. This prototype also comes with a bead that has a timer function. Additional beads with different functions specific to the wearer’s needs and preferences can be ordered.



The project was motivated by my grandparents, and specifically my Grandpa Jack who is an engineer and inventor. He recently got a fall pendant - a plastic device worn around the neck designed to detect falls and call for help - and expressed the need for a better product that looked better, detected falls more accurately and had a longer battery life. So, I decided to make a better one. 

The first reaction people have to this project is “doesn’t the Apple Watch do all of those things?” It does, but there are a few reasons there is a need for a different product: First, the Apple Watch is not accessible for many people from a price point perspective. Second, my grandpa is not interested in using most of the features that the Apple Watch has. Finally, the touch screen on the Apple Watch (and most other smart watches) is difficult to use for people who have limited or diminished mobility, dexterity and/or eyesight. This last point can be said another way: the Apple Watch is not designed for elderly people and most smart products aren’t either. This project, therefore, is motivated by the belief that there should be more digital/smart products that are designed for and with elderly people. This population should not be excluded from the digital era.

When designing this prototype, I used the 7 universal design principals

1. Equitable Use

2. Flexibility in Use

3. Simple and Intuitive Use

4. Perceptible Information

5. Tolerance for Error

6. Low Physical Effort

7.  Size and Space for Approach and Use


From the User Manual:


How It Works

This prototype uses an accelerometer to detect a fall. I am using a Feather Huzzah, which is a wifi enabled microcontroller to read signals from the accelerometer and buttons. When the Feather Huzzah gets the fall signal from the accelerometer (right now it is looking for a change in the average X, Y and Z acceleration values above a certain threshold), it blinks the light/buzzer bead in an SOS pattern. It also connects to the Twilio API through wifi, which sends a text to the wearer saying that a fall has been detected and asks if the wearer needs assistance.

The Feather also has two buttons hooked up to its input pins. One button has been designated as the help button and when pressed, it executes the same functions as when a fall is detected (but this time the text says that it has been told that help has been requested rather than a fall detected). The other button for this prototype has been programmed to be a timer. When pressed, it sends a signal to the Feather Huzzah which then blinks the light/buzzer bead to let the wearer know that the timer has been set and then blinks and buzzes again once five minutes has passed.

You can see the process from concept to prototype here.

You can see the code that runs on the Feather Huzzah here.


Next Steps/Extension

The next step for the fabrication is to create 3D printed and silicone molded buttons. I created 3D sketches on SketchUp and now need to go through the process of printing and molding them.

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I have also been thinking about ways that this bracelet could incorporate some of the abilities that digital apps give us to make our phones and smart devices customizable and modular. As a concept piece, I fabricated a box to act as a charging station and allow the user to re-program the beads of the bracelet.

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What I Learned/Acknowledgements

  • Thank you to Jeff Feddersen for teaching me everything. Before doing this project, I had never done any sort of physical computing. Over the semester I learned everything from basic circuits to digital and analog input and output to serial communication to making things move with motors.  

  • On this project specifically, I learned how to read and interpret accelerometer data and how to use a wifi microcontroller. Thank you to Matt Ross for accelerometer tips and David Azar for timer library help.

  • I learned how to design and model 3D objects (even though I haven’t printed them yet). Thank you to Lola Cantu for teaching me this and all about squishy buttons. And to Arnab Chakravarty for silicone scraps!

  • This process taught me how hard it is to make electronic components both small and look good (thanks also, Jeff, for the warning). Thank you to Idit Barak for wearable design consulting.

  • Most importantly, I learned about designing for and with a specific user and how to make a device communicate with only a few outputs (a buzzer and an LED in this case). Thank you to Mithru Vigneshwara for sharing accessibility design resources. And thank you to Becca Moore for sharing other user case studies.