By Stanley on 2/7/2025
A few months ago, my friend Jack and I created Gluconnect. Gluconnect turns any standard blood-sugar meter (glucometer) into a Bluetooth-enabled one, allowing for the automatic wireless transmission of blood data over Bluetooth. It doubles as a platform where users can easily view, manage, and share their data with family members or trusted healthcare providers.
The Gluconnect app relays data between the Raspberry Pi and backend server: it receives blood reading data packets over Bluetooth (from the Bluetooth transmitter on the Raspberry Pi) which are decoded and displayed in the frontend app, and synchronized with the backend server, where the readings are added to the database, to persist the user’s readings and allow authorized family members/healthcare professionals to see their readings. The user can add these authorized users through the mobile app, and can also set a warning threshold for their account, to warn authorized users in dangerous scenarios. It supports a wide range of glucometers.
The Raspberry Pi runs a custom Gluconnect Bluetooth Service. It first gets the blood reading data from the internal memory of the Glucometer over USB. It broadcasts a Bluetooth Low Energy service transmitting 2 characteristics. A “number of readings” field, which indicates the number of blood readings stored in the Glucometer’s internal memory, and a “reading” field. The app writes the index of the reading it wants to access, and the Raspberry Pi will then send the respective reading using its Bluetooth transmitter when read.
In December, we were announced as the recipients of the Best Overall App Award and winners of the 2024 Congressional App Challenge, in California’s 40th Congressional District (Rep. Young Kim). We are also invited to Capitol Hill to showcase our app in the 2025 #HouseOfCode celebration, which is really nice! The press release can be found at https://youngkim.house.gov/2025/01/14/rep-young-kim-names-ca-40-congressional-app-challenge-winners.
Winning the contest was great, but what I enjoyed the most was working on the project itself. I learned so much from working on this project, like gaining experience with Flutter, Go, JSON, data serialization, mobile app development, and using Raspberry Pi devices. I will 100% work on this type of project again in the future, just because it teaches you so much!
I wrote the Go backend, Bluetooth service running on the Raspberry Pi, and worked on a portion of the frontend. My partner Jack worked on the frontend and an alternative backend implementation in JavaScript. We used Flutter to make the frontend, and NodeJS to make the backend (there is also an in-progress Go implementation).
I used the Python bless library to implement the Bluetooth Low Energy service on the Pi (https://pypi.org/project/bless) and the Python glucometerutils library (https://github.com/glucometers-tech/glucometerutils) to extract readings from the Glucometer over USB.