Active Input Element Serial Interface for Bounce-Free Key Detection
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Solution Overview
Problem
Conventional keyboards face issues with accurate detection due to 'contact bounce' or 'chatter,' leading to misinterpreted key presses, and existing solutions complicate circuitry layout and signal evaluation.
Innovation Solution
A method involving a clock counter, shift register, and data processing unit to simplify the layout and signal evaluation by using a serial interface and eliminating the need for a select line, allowing for accurate detection and control of input elements with reduced complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional keyboard detection methods are used, then contact bounce causes multiple key press detections, but the circuitry layout and signal evaluation become complex
Solution Approach 1:
The patent combines multiple functions (counter, shift register, data evaluation) into a single integrated circuit component, eliminating the need for separate circuitry for each function and simplifying the overall layout while maintaining accurate key press detection
Solution Approach 2:
The integrated circuit performs multiple functions simultaneously: counting clock cycles, shifting data through registers, comparing values, and detecting key presses, making a single component serve universal purposes that previously required multiple separate circuits
2Measurement precision
If conventional keyboard detection methods are used, then contact bounce causes multiple key press detections, but the signal evaluation becomes complex
Solution Approach 1:
The patent merges signal evaluation functions (counting, shifting, comparing) into a single integrated circuit, consolidating complex evaluation logic that previously required multiple separate processing components into one unified device
Solution Approach 2:
The integrated circuit autonomously performs signal evaluation through its internal counter, shift register, and comparison logic, eliminating the need for external microcontroller intervention and simplifying the overall signal evaluation process
Data Source
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AI summary
The present invention refers to a method for operating an active input element and a corresponding input element, input arrangement and computer program product, comprising the steps: a) set value C of clock counter to 0 (S2); b) increase value C of clock counter by 1 and shift data in shift register (5) by one Bit, when detecting a clock information (S3); c) compare (S4) value C of clock counter with a cycle length CLL, and return to step b) if comparison result is negative or proceed to step d) if comparison result is positive; d) read data (DFIFO) from shift register (S5); e) compare (S6) said read data (DFIFO) from shift register (5) with predetermined first data value (Dl), and proceed to step f) if comparison result is positive or proceed to step a) if comparison result is negative; f) write data (DIE) derived from analog input device (S) into shift register (S7) and return to step a).