CN202364197U

CN202364197U - Button detection and LED control circuit

Info

Publication number: CN202364197U
Application number: CN2011204732706U
Authority: CN
Inventors: 黄硕茂
Original assignee: SHENZHEN COMET SCIENCE & TECHNOLOGY Co Ltd
Current assignee: SHENZHEN COMET SCIENCE & TECHNOLOGY Co Ltd
Priority date: 2011-11-24
Filing date: 2011-11-24
Publication date: 2012-08-01
Anticipated expiration: 2021-11-24

Abstract

The utility model discloses a button detection and LED control circuit, comprising a one-chip microcomputer, a button, an LED, and several sets of button detection and LED control units, wherein the button detection and LED control unit comprises a shift register used for data serial input and parallel output; the data input terminal of the shift register is electrically connected with the IO port of the one-chip micrcocomputer; and the data output terminal of the shift register is electrically connected with the button and LED respectively. The utility model provides a button detection circuit and a LED control circuit, featuring simple structure, high reliability, stable performance, substantial reduction of hardware resources, and the decrease of system configuration cost.

Description

A kind of button detects and the LED control circuit

Technical field

The utility model relates to the Single-chip Controlling field, relates in particular to a kind of monolithic processor controlled button and detects and the LED control circuit.

Background technology

Along with development of electronic technology, button detects and LED control is applied on the electronic equipments such as remote controller and mobile phone more and more.Present most of product adopts need not general I/O pin (IO mouth) accomplishing key scan and controlling with LED of single-chip microcomputers; Usually adopt the matrix form scan mode to accomplish; It is more that but this kind mode takies the IO mouth resource of single-chip microcomputer, and when needs scanned button in a large number with control LED, required single-chip microcomputer was also many more; So not only significantly improve manufacturing cost, also caused unnecessary waste.

The utility model content

The purpose of the utility model provides a kind of use amount that can reduce single-chip microcomputer, improves the utilization ratio of single-chip microcomputer IO mouth, can make the circuit structure simple key-press detect and the LED control circuit again.

In order to achieve the above object; The utility model provides a kind of button to detect and the LED control circuit; Comprise single-chip microcomputer, button and LED, comprise that also some groups of buttons detect and the LED control unit, said button detects and the LED control unit comprises a shift register that is used for data serial input and line output; The IO mouth of the data input pin of said shift register and single-chip microcomputer electrically connects, and the data output end of said shift register electrically connects with said button and LED respectively.

Said button detects with the LED control unit and also is provided with divider resistance R1 and R2, said divider resistance R1 respectively with the IO mouth and LED electric connection of single-chip microcomputer, said divider resistance R2 respectively with the IO mouth and the button electric connection of single-chip microcomputer.

Said button detects with the LED control unit and also is provided with some diodes that are used for unidirectional conducting, said diode respectively with the output electric connection of button and shift register.

Said shift register is that shift register 74HC164 is gone into and gone out to 8 bit strings.

The IO mouth of the IN_A of said shift register and IN_B pin and single-chip microcomputer electrically connects, and the data output end Q0-Q7 of said shift register electrically connects with 8 that are provided with unidirectional conducting diode D, LED respectively.

It is simple in structure that the utility model provides a kind of button to detect with the LED control circuit, and reliability is high, and hardware resource is significantly saved in stable performance, minimizing system configuration cost.

Description of drawings

Be described further below in conjunction with the embodiment of accompanying drawing the utility model:

Fig. 1 is the circuit structure block diagram of detection of the utility model button and LED control circuit

Fig. 2 is the circuit structure block diagram of the embodiment of the utility model

Fig. 3 is the circuit theory diagrams of the embodiment of the utility model

Embodiment

Extremely shown in Figure 3 like Fig. 1 is that the utility model button detects and the LED control circuit, and present embodiment adopts 8 bit strings to go into and go out shift register 74HC164, and pin is following:

1--serial input IN_A; 2--serial input IN_B; 3--exports Q0; 4--exports Q1; 5--exports Q2; 6--exports Q3; 10--exports Q4; 11--exports Q5; 12--exports Q6; 13--exports Q7; 7--GND; 8--clock CLK; 9--removes CLR; 14--VCC;

The utility model provides a kind of button to detect and the LED control circuit; Comprise single-chip microcomputer, button and LED; Comprise that also some groups of buttons detect and the LED control unit; Said button detects and the LED control unit comprises a shift register that is used for data serial input and line output, and the IO mouth of the IN_A of said shift register and IN_B pin and single-chip microcomputer electrically connects, and the data output end Q0-Q7 of shift register electrically connects with 8 that are provided with unidirectional conducting diode D, LED respectively.

This button detects with the LED control circuit and is based on the new-type circuit that conventional keys and LED (light-emitting diode or common cloudy charactron) mixed sweep are improved; With logic chip 74HC164 is main element; Drive the LED and the button of maximum quantity; LED and button are one group with 8, and every group only need correspondingly increase LED_COM quantity and KEY_COM quantity (each indicates one group among Fig. 3, below describe with one group).Operation principle is following:

One, button detects scanning:

1) MCU is a low level through the output pin Q0-Q7 that SDA and CLK data wire set gradually shift register 74HC164, and all the other pin are high level;

Whether be low level, if low, show that then KEY1-KEY7 has key to press if 2) detecting LED_COM, MCU notes the detected state of each button;

3) scanned after again according to the height state of every group of button of MCU record, confirm that through program which key presses.

Two, LED shows control:

1) MCU confirms that at first which LED need light, and finds out the pin position Q0-Q7 that the LED that need light links to each other with shift register 74HC164;

2) 8 output pin Q0-Q7 that through SDA and CLK data wire shift register 74HC164 are set are corresponding level (pin that links to each other with LED that needs are lighted is set to high level, and what do not work is set to low level);

3) LED_COM being set is low level.

More than be that preferable enforcement to the utility model specifies; But the utility model is created and is not limited to said embodiment; Those of ordinary skill in the art also can make all equivalent variations or replacement under the prerequisite of the utility model spirit, distortion that these are equal to or replacement all are included in the application's claim institute restricted portion.

Claims

1. a button detects and the LED control circuit; Comprise single-chip microcomputer, button and LED; It is characterized in that: comprise that also some groups of buttons detect and the LED control unit; Said button detects and the LED control unit comprises a shift register that is used for data serial input and line output, and the IO mouth of the data input pin of said shift register and single-chip microcomputer electrically connects, and the data output end of said shift register electrically connects with said button and LED respectively.

2. button according to claim 1 detects and the LED control circuit; It is characterized in that: said button detects and the LED control unit also is provided with divider resistance R1 and R2; Said divider resistance R1 electrically connects with the IO mouth of single-chip microcomputer and LED respectively, said divider resistance R2 respectively with the IO mouth and button electric connection of single-chip microcomputer.

3. button according to claim 1 detects and the LED control circuit; It is characterized in that: said button detects with the LED control unit and also is provided with some diodes that are used for unidirectional conducting, said diode respectively with the output electric connection of button and shift register.

4. button according to claim 1 detects and the LED control circuit, and it is characterized in that: said shift register is that shift register 74HC164 is gone into and gone out to 8 bit strings.

5. button according to claim 4 detects and the LED control circuit; It is characterized in that: the IO mouth of the IN_A of said shift register and IN_B pin and single-chip microcomputer electrically connects, and the data output end Q0-Q7 of said shift register electrically connects with 8 that are provided with unidirectional conducting diode D, LED respectively.