Remember the good old PDAs or Personal Digital Assistants that people used for taking notes, keeping schedules, keeping a tab ...

The circuit is extremely simple, comprising the sensor, an Arduino Nano, and an OLED display. This device is handy because its voltage output has a known relationship to the gauss level the sensor ...

This data is passed to an ESP-32 and Teensy 3.5. From reading the code, it appears the Teensy is responsible for logging data from the CAN bus on an SD card, and running a small OLED display.