Method and apparatus for enhanced gauge resolution
AssigneeDelco Electronics Corporation
InventorsDouglas J. King, Thomas J. Dolehanty
Life of this patent
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Abstract
An instrument cluster gauge system includes a gauge, a microcontroller for sampling a parameter value, and a low resolution digital gauge driver responsive to the microcontroller but capable of only a limited number of output drive signals corresponding to fixed gauge positions. The gauge is driven to positions between the fixed positions by rapidly alternating the drive signal between neighboring fixed positions, so that the gauge responds to the average value of the signal. An algorithm determines the relative number of each of the neighboring positions in the drive signal needed to attain an average signal near the parameter value. Smoothness and accuracy are enhanced.
Claims10
In a gauge having a limited resolution digital driver circuit limited to producing drive signals for discrete gauge positions, and a microcontroller for receiving an input signal and supplying drive data to the driver circuit, a method of controlling the gauge to points between the discrete positions comprising the steps of:
- reading a desired gauge position from the input signal and expressing the position with a resolution greater than that of the gauge driver;
- and
- energizing the driver circuit to alternately supply signals for the two discrete gauge positions nearest the desired position, whereby the signals are averaged by the gauge to achieve the desired gauge position.
Apparatus for enhancing gauge resolution comprising:
- a microcontroller for receiving an input signal and supplying drive data corresponding to the value of the input signal;
- a gauge driver comprising a limited resolution digital circuit coupled to the microcontroller for receiving the drive data for producing gauge drive signals for discrete positions;
- the microcontroller being programmed to
- read a desired gauge position from the input signal and express the position with a resolution greater than that of the gauge driver, and
- energize the driver circuit to alternately supply signals for the two discrete gauge positions nearest the desired position;
- and
- a gauge driven by the gauge driver to average the signals for the two discrete gauge positions to achieve the desired gauge position.
Dependencies are inferred from the claim text.