CN209170335U

CN209170335U - A kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal

Info

Publication number: CN209170335U
Application number: CN201920175862.6U
Authority: CN
Inventors: 李光平
Original assignee: Nanning Institute
Current assignee: Nanning University; Nanning Institute
Priority date: 2019-02-01
Filing date: 2019-02-01
Publication date: 2019-07-26
Anticipated expiration: 2029-02-01

Abstract

The utility model provides a kind of matrix keyboard circuit that key jitter and interrupt signal output are eliminated with hardware, which is made of disappear twitter circuit, four input nand gates and Schmidt's NAND gate of matrix keyboard, the RC of 4x5.When key is not pressed, H1 to the H4 of key keeps weak pull-up state, and L1 to L5 keeps strong pull-down state, when pressing key pressing, weak pull-up is pulled low, the reversion of NAND gate output level, the charging of RC circuit is given, band is formed after Schmidt's NAND gate and disappears the interrupt signal trembled.Circuit changes classical matrix keyboard using the method for largely consuming single-chip microcontroller or other microcontroller resources in software timing scanning and software for jitters elimination.Single-chip microcontroller or other microcontroller resources have largely been saved, the consumption of electric energy is thereby reduced.

Description

A kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal

Technical field

The utility model relates to a kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal, belongs to application electric technology Field.

Background technique

Matrix keyboard circuit is very widely used in daily life, with the improvement of living standards, various intelligence Energy product appears in our life.For intellectual product, the quantity of key sometimes requires that comparison is more.But in order to save Cost, is generally used that port is less, the less single-chip microcontroller of resource or other microcontrollers.For meet key demand it is more, The less single-chip microcontroller of resource or other microcontroller controlling function products devise a kind of band hardware for jitters elimination and interrupt signal Matrix keyboard circuit solve the problems, such as that key is more, resource is few.

Utility model content

The purpose of the utility model is to provide a kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal is used for key In the circuit of more, the less single-chip microcontroller of resource or other microcontrollers.

The specific technical solution that the utility model is taken is as follows:

A kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal, it is characterized in that: the circuit includes the matrix key of 4x5 Disk, resistance R1, capacitor C1, four input nand gate U1, two input Schmidt's NAND gate U2, connecting terminal H1 to H4, connecting terminal L1 to L5, connecting terminal INT.Wherein the left end of 4x5 key is connected to capable connecting terminal H, and the right end of key is connected to pair The connecting terminal L that should be arranged；Input terminal H1 to the H4 of Input terminal block is connected to the input terminal of four input nand gate U1；Resistance R1 with C1 series connection stroke RC filter circuit, R1 input four input nand gate output end U1 of termination, the other end are connected with C1, and C1 mono- is terminated Ground, other end are connected with R1；Two input terminals of input nand gate two are connected with the concatenated node of RC, and output point connects output end Sub- INT.

Detailed description of the invention

Fig. 1 is a kind of circuit diagram of the matrix keyboard circuit with hardware for jitters elimination and interrupt signal of this patent.

Specific embodiment

The utility model is described further with reference to the accompanying drawing.

The application method of the utility model are as follows: under normal circumstances, H1 to H4 utilizes single-chip microcontroller or other miniature controls Device makes port be in weak pull-up state；L1 to L5 is connected to single-chip microcontroller or the I/O port of other microcontrollers, makes to keep being in Strong pull-down state.In no key-press input, single-chip microcontroller or other microcontrollers may be at it is standby or other It is not related to the work of key.When occurring by key pressing, since the impedance of key is very low, the wherein single line of H1 to H4 it is weak on Drawing is directly connected in the wherein single line of L1 to L5.The wherein single line level of H1 to H4 is pulled low.After input variation, due to The input terminal of four input nand gates is not all of high level, and the level of output end becomes high level by original low level；With it is non- Gate output terminal is by R1 resistance to capacitor charging.When shaking input, since shaky time is short, capacitor charging can not be made all enough Voltage.When being only more than RC time constant by the key pressing time, Schmidt NAND gate U2 output level is inverted, and has been reached to disappear and trembled Purpose.The interruptive port that U2 output end is connected to single-chip microcontroller perhaps other microcontrollers can wake up single-chip microcontroller or other Microcontroller allows program to enter and interrupts keystroke handling program.Finally reach eliminate key jitter and save single-chip microcontroller or its The purpose of his microcontroller resource.

This using new-type circuit it is characterized in that: the circuit include the matrix keyboard of 4x5, electronics R1, capacitor C1,4 input with NOT gate U1, two input Schmidt's NAND gate U2, connecting terminal H1 to H4, connecting terminal L1 to L5, connecting terminal INT.Wherein 4x5 The left end of key is connected to capable connecting terminal H, and the right end of key is connected to the connecting terminal L of respective column；Input terminal block Input terminal H1 to H4 be connected to the input terminal of four input nand gate U1；Resistance R1 connects stroke RC filter circuit with C1, and R1 is defeated Enter four input nand gate output end U1 of termination, the other end is connected with C1, and the one end C1 ground connection, other end is connected with R1；Two inputs Two input terminals of NAND gate are connected with the concatenated node of RC, and output point connects output terminal INT.

Claims

1. a kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal, it is characterized in that: the circuit includes the matrix key of 4x5 Disk, resistance R1, capacitor C1, four input nand gate U1, two input Schmidt's NAND gate U2, connecting terminal H1 to H4, connecting terminal L1 to L5, connecting terminal INT, wherein the left end of 4x5 key is connected to capable connecting terminal H, and the right end of key is connected to pair The connecting terminal L that should be arranged；Input terminal H1 to the H4 of Input terminal block is connected to the input terminal of four input nand gate U1；Resistance R1 with C1 series connection stroke RC filter circuit, R1 input four input nand gate output end U1 of termination, the other end are connected with C1, and C1 mono- is terminated Ground, other end are connected with R1；Two input terminals of input nand gate two are connected with the concatenated node of RC, and output point connects output end Sub- INT.

2. a kind of matrix keyboard circuit with hardware for jitters elimination and interrupt signal according to claim 1, it is characterized in that: circuit Parameter U1 uses 4 input nand gates, and U2 exports NAND gate using Schmidt's type two, and R1 resistance uses 10k valued resistor, and C1 is adopted With 10uF non-polar capacitor.