Smart OLED Digital Compass

This paper describes an ESP32-based digital com-pass built around a QMC5883L three-axis magnetometer and anSSD1306 128 × 64 monochrome OLED display. The firmwareincludes a custom display driver, a 1024-byte framebuffer, andgraphics routines for pixels, lines, circles, and seven-segmentdigits. The interface provides Compass, Debug, and Manualviews. In Manual View, two potentiometers provide alternate X/Yinputs, and a push button changes the active view. The documentpresents the circuit design, simulation wiring, PCB layout, and averification plan. Numerical claims for heading accuracy, timing,and power are omitted because measured results have not beensupplied.