Hall sensors are magnetic sensors that detect magnetic flux passing through a Hall element which then generates a voltage that can be detected by electronic sensing circuits. Hall sensors can be used to detect rotation as well as position and help with certain navigation in robots, as well as detection of open/close position of a lid or compartment doors on certain robots. ROHM’s Hall sensors have built in Hall element as well as signal processing circuits to detect the electrical signal generated by the Hall element as it detects magnetic flux.