A powered fastener driver includes a motor and a lifter configured to be rotatable by the motor about a rotational axis. The powered fastener driver also includes a piston urged towards a bottom-dead-center position to drive the fastener into a workpiece, and a magnet movable in response to rotation of the lifter. The magnet includes a first pair of poles including a first north pole face and a first south pole face, and a second pair of poles including a second north pole face and a second south pole face. The first north pole face is adjacent the second south pole face. A pole junction is defined between the first pair of poles and the second pair of poles. The powered fastener driver also includes a sensor configured to detect the pole junction, and a controller configured to control the motor based on detection of the pole junction.