LazyDays Creation built a compact, portable digital compass based on an ESP32-S3 Super Mini and a three-axis magnetometer. He chooses an ESP32-S3 Super Mini because it is capable enough for the project while also including a built-in lithium-battery charging circuit. A round colour display gives the finished device a distinctive watch-like appearance, while the rechargeable battery allows it to operate as a portable handheld compass.
The build begins with soldering header pins to the ESP32 board, then testing the round display and connecting the magnetometer. The sensor measures magnetic-field components on three axes, enabling the ESP32 to calculate a heading. After confirming the basic hardware works, the creator makes a simple heading indicator, then prepares a custom adapter PCB that brings the ESP32, display, sensor, and power connections together into a more compact assembly. The user interface is designed in SquareLine Studio, exported into the firmware project, and uploaded to the board.
A key takeaway is that the magnetometer requires calibration after it is installed in its final physical orientation. Mounting position, nearby electronics, metal parts, and wiring can affect its magnetic readings, so calibration is necessary to achieve an accurate directional heading. Once calibrated, the project delivers a functional mini digital compass with a polished circular graphical interface, illustrating a practical combination of ESP32 hardware, display design, battery power, and sensor processing.
