Abstract: The disclosure relates to a magnetometer in which direction of the Earth's magnetic field is determined on the basis of time variant differences in the inductance of a sensor coil of the digital compass which is a function of the orientation of the sensor coil with respect to the Earth's magnetic field. The magnetometer includes a sensing coil, a feedback resistor, and a comparator.

Abstract: The present invention refers to a magnetometer (2) comprising a relaxation oscillator build up by a sensing coil (10), a feedback resistor (118) and a comparator (20), wherein an output node (107) of the comparator (20) is connected via the feedback resistor (118) to a first input node (102) of the comparator (20) and via the sensing coil (10) to a second input node (103) of the comparator (20), wherein the first input node (102) is controllable by an alternating first input signal (110) and wherein the second input node (103) is controllable by an inversely alternating second input signal (111).

Abstract: A compass system includes a magnetic field sensor for measuring an ambient magnetic field and a magnetic field generator, corresponding to the magnetic field sensor, configured to generate a reference magnetic field. The magnetic field sensor is configured to measure the reference magnetic field. The compass system further includes a control circuit operably connected to the magnetic field sensor and magnetic field generator, wherein the control circuit is configured to process the ambient magnetic field and the reference magnetic field measurements to determine an absolute reference field strength for use in calibrating the compass system.

Abstract: A method for compensating for frequency shifts during transmission of an RF control signal includes receiving a request to enter a transmission mode from a user. A carrier signal having a frequency is generated and the frequency of the carrier signal is measured. The measured frequency of the carrier signal is compared to a desired frequency to determine if there is a difference between the measured frequency and the desired frequency. If there is a difference, it is determined if data is being modulated on the carrier signal. If data is not being modulated on the carrier signal, a correction is applied to the carrier signal frequency.

Abstract: A method for training a trainable transmitter in a vehicle includes receiving a request to enter a training mode of the trainable transmitter from a user. In response to the request, default mode data is retrieved from a memory and transmitted for a predetermined time. Upon expiration of the predetermined time, the trainable transmitter begins a training mode.

Abstract: A compass system comprises a magnetic field sensor for measuring an ambient magnetic field and a magnetic field generator, corresponding to the magnetic field sensor, configured to generate a reference magnetic field. The magnetic field sensor is configured to measure the reference magnetic field. The compass system further comprises a control circuit operably connected to the magnetic field sensor and magnetic field generator, wherein the control circuit is configured to process the ambient magnetic field and the reference magnetic field measurements to determine an absolute reference field strength for use in calibrating the compass system.