Switching Hall sensor is used for anti-theft, and its output signal can be considered as standard CMOS level after shaping and transformation. It can be directly represented by keys (design a key circuit by yourself), and when pressed, it means 0 (that is, when the magnetic steel passes through the Hall sensor), but not 1 (when no magnetic steel passes through). This signal can be directly sent to the external interrupt port to trigger the interrupt of the single chip microcomputer.