Spetember 2025 | Blue Logger

Written By Thomas .

-1- The idea

The goal is to make a data logger that can acomodate various sensors while focusing on three main aspects :

  • Ease of use

  • Compact size

  • Portability

For the power source, the LIR2032H coin cell battery was selected. It is easy to use, as a small form factor, and can be easily swaped or recharged.

The only drawbacks is its low capacity at only 70 mAh. To address this, a low-power MCU is required. For the user interface, data will be retrieved via a smartphone using Bluetooth, which keeps the design simple and accessible. This is why the NINA-B112-04B module was chosen.

-2- Early prototype

The EVK-NINA-B112 evaluation board from u-blox fits exactly this project and provides an excellent platform for early prototyping and development.

The main goal of the prototype is to verify whether the battery can provide enough runtime to log data for several hours. This stage also enables firmware development and testing before the design of the final PCBs.

Thomas .