Abstract: This article proposes a design scheme for a weak magnetic field measurement system based on STM32 using HMC5883L sensor and a weak magnetic field measurement system is built, which is divided into hardware and software parts. The hardware part is instrument construction, and the software part is data processing. The data processing model is implanted into a microcontroller, which displays the processed data on the display end. The system calibrates the measurement system based on the officially announced magnetic induction intensity at a certain point in space. The calibrated measurement system can be used to measure the magnetic induction intensity at any point in space. In order to verify the accuracy of the measurement results of the system, the measured values of the magnetic induction intensity at the midpoint of the energized solenoid axis were compared and analyzed with the corresponding calculated magnetic induction intensity theory values of the excitation current. The results showed that the relative error of 70 current measurement points decreased exponentially with the linear increase of current, and the system could measure weak magnetic fields relatively accurately.

Key words: weak magnetic field, HMC5883 sensor, STM32 microcontroller, energized solenoid, current source