Apparatus and method for calibrating a timing circuit in a remote keyless entry system using programmable commands
AssigneeAlps Automotive, Inc.
InventorsWilhelm Leichtfried, Charles McDowell, James Dulgerian
Life of this patent
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Abstract
A method of calibrating a remote keyless entry system adjusts a timing circuit that is a unitary part of a microprocessor. The method drives a plurality of inputs to the microprocessor to a logic state, monitors the output of the microprocessor, and programs a calibration factor within the microprocessor based on the output of the microprocessor. The calibration factor controls an output frequency of the timing circuit.
Claims20
A method of calibrating a remote keyless entry system, comprising:
- driving a plurality of inputs of a microprocessor of the remote keyless entry system to a logic high state, the microprocessor being a unitary part of a timing circuit, the timing circuit comprising a plurality of frequency dependent components that are coupled to a plurality of switches, respectively;
- monitoring an output of the microprocessor;
- and
- programming a calibration factor within the microprocessor based on the output of the microprocessor, the calibration factor controlling an output frequency of the timing circuit.
A method of calibrating a remote keyless entry system, comprising:
- driving a plurality of inputs of a microprocessor of the remote keyless entry system to a logic high state, the microprocessor being a unitary part of a timing circuit, the timing circuit comprising a plurality of frequency dependent components that are respectively coupled to a plurality of switches;
- measuring a pulse width of an output of the microprocessor;
- comparing a duration of the pulse width to a reference time period;
- and
- programming a K-factor and an oscillator calibration register resident to the microprocessor based on the output of the microprocessor by executing an up and a down command, the K-factor and the oscillator calibration register controlling an output frequency of the timing circuit.
A method of calibrating a remote keyless entry system, comprising:
- driving a plurality of inputs of a microprocessor of the remote keyless entry system to a logic high state, the microprocessor being a unitary part of a timing circuit, the timing circuit comprising a plurality of capacitors that are respectively coupled to a plurality of transistors;
- measuring a pulse width of an output of the microprocessor;
- comparing a duration of the pulse width to a reference time period;
- programming a K-factor and an oscillator calibration register resident to the microprocessor using at least one up or down command based on the output of the microprocessor, the K-factor and the oscillator calibration register controlling an output frequency of the timing circuit;
- validating a bit timing output of a radio frequency signal transmitted by a radio frequency circuit coupled to the microprocessor by monitoring a digital signal;
- monitoring a current drawn by the microprocessor when in a sleep mode;
- and
- logging data in a remote database.
Dependencies are inferred from the claim text.