Key scanning device and system

Abstract

The invention provides a key scanning device and system, and relates to the technical field of circuit control. The device can comprise a controller, a key judgment circuit, and a key circuit. The keyjudgment circuit also can comprise an input buffer and a comparator, and can be connected with the controller and the key circuit. The key circuit is used for outputting at least two types of key signals to the key judgment circuit from a target pin, and the key judgment circuit is used for detecting a voltage value of the target pin. The device and system are simple in structure, and are easy toimplement. The controller controls the operation state of the comparator based on the voltage value, and facilitates the reduction of the system consumption. In addition, the controller determines aconduction key in the key circuit according to the voltage value, and enables one pin to achieve the functions of a plurality of keys, thereby reducing the resources occupied by pins.

Description

technical field [0001] The present invention relates to the technical field of circuit control, and in particular, to a key scanning device and system. Background technique [0002] As a human-machine interface, the key scanning system is widely used in existing electronic products. A button usually corresponds to an I / O (Input / Output, input / output) port on the controller. When there are many buttons, the controller needs more I / O ports, and the I / O ports of the controller are limited, and it is necessary to increase the hardware to expand the I / O ports, thereby increasing the cost. In the case of fewer pins (also known as pins) resources, although ADC (Analog-to-Digital Converter) can be used to implement one pin for multiple buttons, this method has defects For example, the ADC needs to work all the time or wake up regularly, resulting in high standby power consumption. Therefore, how to provide a solution that can solve the above problems has become a major problem for...

AI Technical Summary

Problems solved by technology

In the case of relatively few pins (also known as pins) resources, although ADC (Analog-to-Digital Converter, analog-to-digital converter) can be used to realize the use of multiple buttons for one pin, this method has defects. , for example, the ADC needs to work all the time or wake up regularly, resulting in high standby power consumption

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