A novel magnetoelectronic device incorporating a single microstructured ferromagnetic film and a micron scale Hall cross was fabricated and characterized at room temperature. Magnetic fringe fields from the edge of the ferromagnet generate a Hall voltage in a thin film semiconducting Hall bar. The sign of the fringe field, as well as the sign of the output Hall voltage, is switched by reversing the magnetization of the ferromagnet. This new device has excellent output characteristics and scaling properties, and may find application as a magnetic field sensor, nonvolatile storage cell, or logic gate. ©1997 American Institute of Physics.