CN217008199U

CN217008199U - Display composite multi-key circuit

Info

Publication number: CN217008199U
Application number: CN202122990386.3U
Authority: CN
Inventors: 肖美英
Original assignee: Shenzhen Dongzhixin Technology Co ltd
Current assignee: Shenzhen Dongzhixin Technology Co ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2022-07-19
Anticipated expiration: 2031-12-01

Abstract

The utility model provides a display composite multi-key circuit, which belongs to the technical field of electronic circuits and comprises a controller chip circuit, and is characterized in that: the display circuit and the key circuit are connected with the controller chip circuit through the public GPIO port circuit. On the basis of realizing the same function, the circuit greatly reduces the material cost of the PCB of the sound box and the processing cost of PCB surface mounting, the traditional circuit needs a large number of resistors, the application only needs 2 keys, the production efficiency can be improved, if more keys are needed in different schemes, the A circuit only needs to add 1 GPIO and 1 resistor according to the principle to increase 7 keys, and the traditional circuit needs 8 resistors with 7 keys, so that the scheme saves a plurality of pins, chips with fewer pins can be selected, and the chip cost is saved.

Description

Display composite multi-key circuit

Technical Field

The utility model relates to the technical field of electronic circuits, in particular to a display composite multi-key circuit.

Background

GPIOs of a display and a key in a traditional circuit are used separately, so that a control chip GPIO is often insufficient, and each key in a keyboard needs a resistor for matching, so that more devices are needed. As shown in fig. 3, the conventional circuit schematic diagram shows that the number of keys in fig. 3 requires 16 resistors R3-R18 and two ADC pins ADK1 and ADK2, and the display screens LED _ a-LED _ G occupy 9 pins. In order to better save the cost of the IO port and the device, a circuit using fewer IO ports and fewer devices needs to be designed, so as to save the cost.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a display composite multi-key circuit, which solves the technical problem mentioned in the background technology.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

the utility model provides a show compound many button circuits, includes controller chip circuit which characterized in that: the display circuit and the key circuit are connected with the controller chip circuit through the public GPIO port circuit.

Furthermore, the public GPIO port line consists of 7 GPIO port lines, and each GPIO port line is connected with one GPIO port.

Furthermore, 7 wires led out from the display circuit are respectively connected with 7 GPIO port circuits one by one.

Furthermore, the key circuit comprises a first unit and a second key unit, and the first unit and the second key unit are respectively connected to the 7 GPIO port lines.

Furthermore, the first unit comprises 7 keys and a resistor R1, one end of each of the 7 keys is connected with one of the 7 GPIO port circuits, the other end of each of the 7 keys is connected with one end of the resistor R1, and the other end of the resistor R1 is connected with a power supply.

Further, the first unit comprises 7 keys and a resistor R2, one ends of the 7 keys are respectively connected with the 7 GPIO port circuits one by one, the other ends of the 7 keys are connected with one end of a resistor R2, and the other end of the resistor R2 is grounded.

Due to the adoption of the technical scheme, the utility model has the following beneficial effects:

on the basis of realizing the same function, the circuit greatly reduces the material cost of the PCB of the sound box and the processing cost of the PCB paster, the traditional circuit needs a large number of resistors, the circuit only needs 2 resistors, the production efficiency can be improved, if more keys are needed in different schemes, the A circuit only needs 1 GPIO and 1 resistor according to the principle to increase 7 keys, and the traditional circuit needs 8 resistors by adding 7 keys, so that the scheme saves a plurality of pins, chips with fewer pins can be selected, and the chip cost is saved.

Drawings

FIG. 1 is a block circuit diagram of the present invention;

FIG. 2 is a circuit schematic of the present invention;

FIG. 3 is a schematic diagram of a conventional circuit of the present invention;

FIG. 4 is a diagram showing the appearance and structure of the display circuit according to the present invention;

fig. 5 is a schematic diagram of a display circuit of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings by way of examples of preferred embodiments. It should be noted, however, that the numerous details set forth in the description are merely for the purpose of providing the reader with a thorough understanding of one or more aspects of the present invention, which may be practiced without these specific details.

As shown in fig. 1-2, a display composite multi-key circuit comprises a controller chip circuit, a public GPIO port circuit, a display circuit, and a key circuit, wherein the display circuit and the key circuit are both connected to the controller chip circuit through the public GPIO port circuit. The public GPIO port line consists of 7 GPIO port lines, and each GPIO port line is connected with one GPIO port. 7 lines led out from the display circuit are respectively connected with 7 GPIO port lines one by one.

As shown in fig. 2, the key circuit includes a first unit and a second key unit, and the first unit and the second key unit are respectively connected to 7 GPIO port lines. The first unit comprises 7 keys and a resistor R1, one ends of the 7 keys are respectively connected with the 7 GPIO port circuits one by one, the other ends of the 7 keys are connected with one end of a resistor R1, and the other end of the resistor R1 is connected with a power supply. The first unit comprises 7 keys and a resistor R2, one ends of the 7 keys are respectively connected with the 7 GPIO port circuits one by one, the other ends of the 7 keys are connected with one end of a resistor R2, and the other end of the resistor R2 is grounded.

In fig. 2, the nixie tube display screen is driven by 7 chip pins (LED _ a to LED _ G), and the 7 pins are directly multiplexed by the key, which only needs two resistors R1 and R2. Circuit connection description, the numbers in the figures are consistent for the lines connected together: if VDDIO is connected to the 7 th pin of the left chip and the upper end of the resistor R1, the 7 th pin of the master control is connected with one end of the resistor R1; the LED _ A is connected with the other ends of the keys S13 and S14 of the chip 27. Because the chip pins are limited, if the scheme omits a plurality of pins, a chip with fewer pins can be selected, such as the chip shown in fig. 2 and 3. Can be changed into a 24-pin chip, thereby further saving the cost.

In the same number of keys in the conventional fig. 3, 16 resistors R3 to R18 and two ADC pins ADK1 and ADK2 occupy 9 pins in addition to display screens LED _ a to LED _ G.

As shown in fig. 4 and 5, according to the unidirectional conduction characteristic of the LED, the front and back of the two legs can be respectively connected to 2 LEDs, as shown in fig. 5, the 1-leg high level and the 2-leg low level a1 are lit, whereas the 1-leg low level and the 2-leg high level F1 are lit, and do not interfere with each other: and 7 pins can scan and light 7 × 6-42 LED segments.

And (3) scanning:

use 1 foot as com mouth, 1 foot high level, 2 ~ 7 feet are SEG, the IO output low level that the LED section that needs to lighten corresponds, the section that need not lighten, IO mouth establish to input high resistance attitude (do not export high neither output low, in other words unsettled) after having scanned 1 foot, use 2 feet as com mouth, 1, 3 ~ 7 to SEG, the process is the same as above

Example (c): the 1 st bit shows "7" and the others do not show, then A1\ B1\ C1 needs to be lightened up

1 st scanning period: 1 pin high level, 2, 3 pins low level. 4 th scanning period: 4 feet high level, 1 feet low level, 7 feet are 7 periods, and each period is 1 ms. Scanning a round for 7 ms.

Due to the persistence of vision of people and the afterglow effect of Light Emitting Diodes (LEDs), even though the nixie tubes are not lighted at the same time actually, as long as the scanning speed is fast enough, the impression is a group of stable display without flicker.

The multiplexing key is then done at 8ms and the display is turned off briefly at 8ms, this time for detecting the key status.

Because the LED is only turned off for 1ms, and the LED has afterglow which is very short for the recognition speed of human eyes, and can not be detected to flicker

The nixie tube display screen is driven by scanning in turn, for example, 1ms scans 7 groups in a group of COMLED images, one period is 7ms, scanning is suspended at the 8 th ms, 7 driving pin software is set to be in an input state, configurable pull-up and pull-down resistors inside 7 IO ports of a chip are started, and logic level states of keys corresponding to pins are read respectively, so that whether the corresponding keys are pressed or not is judged. By utilizing the inertia of display afterglow and human eyes of the nixie tube, the display effect of the nixie tube screen is not influenced by turning off scanning for a short time. The effect of saving circuit cost can be realized by simple existing software control.

Such as: judging whether an S1 key is pressed down, setting the pin level of the LED _ G as input and opening an internal pull-down resistor in the 8 th ms of the period of the scanning screen, if the key is pressed down, pulling the pin level of the LED _ G high by VDDIO, and reading a high level; no press is low when pulled down, and so on.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims

1. The utility model provides a show compound many keying circuits, includes controller chip circuit, its characterized in that: the display circuit and the key circuit are connected with the controller chip circuit through the common GPIO port circuit;

the public GPIO port line consists of 7 GPIO port lines, and each GPIO port line is connected with one GPIO port;

7 wires led out from the display circuit are respectively connected with 7 GPIO port circuits one by one;

the key circuit comprises a first key unit and a second key unit, wherein the first key unit and the second key unit are respectively connected to 7 GPIO port circuits;

the first unit comprises 7 keys and a resistor R1, wherein one end of each of the 7 keys is respectively connected with the 7 GPIO port circuits one by one, the other ends of the 7 keys are respectively connected with one end of a resistor R1, and the other end of the resistor R1 is connected with a power supply;

the first unit comprises 7 keys and a resistor R2, one ends of the 7 keys are respectively connected with the 7 GPIO port circuits one by one, the other ends of the 7 keys are connected with one end of a resistor R2, and the other end of the resistor R2 is grounded.