Key multiplexing circuit and POS machine

Abstract

The invention discloses a key multiplexing circuit and a POS machine. A key in a key matrix array is connected with a power supply voltage according to user input so as to generate a direct current voltage and a starting trigger signal; the switch circuit generates a key trigger signal according to the direct-current voltage; the control circuit turns over the level of the enable adjustment signalwhen the duration of the key trigger signal is greater than or equal to a preset duration or obtains a function key value when the duration of the key trigger signal is less than the preset duration;the startup and shutdown regulation and control circuit generates a transformation enable signal according to the startup trigger signal and the enable adjustment signal of the first level and generates a transformation enable signal according to the stop of the enable adjustment signal of the second level; the step-down circuit generates the first voltage according to the power supply voltage and the transformation enable signal and stops generating the first voltage according to the termination of the transformation enable signal, multiplexing of one general key in the key matrix array is realized, the circuit structure is simple, the cost is low, the number and space of keys are saved, and the practicability is high.

Description

technical field [0001] The application belongs to the technical field of key multiplexing, and in particular relates to a key multiplexing circuit and a POS machine. Background technique [0002] The key switch mainly refers to the light touch key switch, also called light touch switch, because of its advantages of small contact resistance, precise operating force error, and diversified specifications, it has been widely used in electronic equipment and white goods. application. By inputting various commands and characters through key switches, the equipment can be effectively controlled, such as switching on and off in electronic equipment. There can be multiple key switches in one device, but for small devices, generally only a few key switches can be set on the panel due to insufficient space. The key switch needs to be reused, that is, one key switch can realize multiple functions. At present, the traditional button multiplexing method is generally implemented through...

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Problems solved by technology

[0004] The purpose of this application is to provide a button multiplexing circuit and a POS machine, aiming at solving the complex structure and complex structure of the button multiplexing circuit existing in the traditional POS machine, and the inability to realize switch and key on the basis of the original key array. Functional reuse is not conducive to optimizing the appearance and volume of the product

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