An electronic device can include a first and second portions that are pivotally coupled to each other so that the electronic device can have at least a closed configuration and an open configuration. A magnetic sensor system can be carried by the electronic device to detect the closed configuration so that the electronic device can automatically turn to a mode, such as a sleep mode, when the electronic device is bought to the closed configuration. A magnetic sensor can have a detection axis that targets a horizontal component of a magnetic field. A triggering magnetic element can be laterally offset relative to the magnetic sensor. The magnetic sensor can also be a magneto-resistive sensor. The electronic device can also include a second set of magnetic sensor system to confirm when the electronic device is brought to the closed configuration.