LED display and key multiplexing circuit, control circuit, control board and electronic equipment

Abstract

The embodiment of the utility model discloses an LED display and key multiplexing circuit, a control circuit, a control board and electronic equipment. According to the embodiment of the utility model, at least one scanning branch is arranged, each scanning branch comprises a first number of LED units and a second number of key units, and the positive electrode ends of the LED units and the first ends of the key units in the same scanning branch are used for being connected with the same column signal output ports in the driving chip. Each column signal output port in the driving chip is connected with a grounded pull-down resistor, and the positive electrode ends of the LED units and the first ends of the key units in different scanning branches are used for being connected with different column signal output ports in the driving chip. The negative ends of the LED units in the same scanning branch are used for being connected with different row signal output ports in the driving chip, and the second ends of the key units in the same scanning branch are used for being connected with different row signal output ports in the driving chip. The multiplexing of the row signal output port and the column signal output port of the driving chip is realized, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of integrated circuits, and in particular to an LED display and key multiplexing circuit, a control circuit, a control panel and electronic equipment. Background Art

[0002] At present, the LED matrix and the button matrix need to be controlled separately and independently. In addition to providing an IO interface to control the driver chip for LED image display, the main control chip also needs to be equipped with an additional IO interface to read the button status to meet the row and column scanning requirements of button detection.

[0003] However, when there are a large number of LED lights and buttons, the I / O interface resources of the main control chip are likely to be in short supply. If further expansion of buttons or LED lights is required, the number of I / O interfaces of the main control chip can only be increased, resulting in increased costs. Summary of the invention

[0004] The utility model provides an LED display and key multiplexing circuit, a control circuit, a control board and an electronic device, which solves the problem that when there are a large number of LED lamps and keys, the I / O interface resources of the main control chip are in short supply, and directly increasing the number of I / O interfaces of the main control chip will lead to increased costs. The utility model realizes that the driver chip can support LED unit scanning and key scanning of the same number as the LED units, and the main control chip does not need to provide additional I / O interfaces for key scanning, which effectively reduces the number of I / O interfaces of the main control chip, can reduce wiring, simplify PCB boards, and reduce the cost of the main control chip.

[0005] In the first aspect, an embodiment of the utility model provides an LED display and key multiplexing circuit, comprising at least one scanning branch, each of the scanning branches comprising a first number of LED units and a second number of key units, the positive terminal of the LED unit and the first end of the key unit in the same scanning branch are used to be connected to the same column signal output port in a driver chip, each column signal output port in the driver chip is connected to a grounded pull-down resistor, the positive terminal of the LED unit and the first end of the key unit in different scanning branches are used to be connected to different column signal output ports in the driver chip, the negative terminal of the LED unit in the same scanning branch is used to be connected to different row signal output ports in the driver chip, and the second end of the key unit in the same scanning branch is used to be connected to different row signal output ports in the driver chip.

[0006] In a second aspect, an embodiment of the utility model provides a control circuit, which includes a driver chip and the LED display and button multiplexing circuit described in any one of the embodiments of the utility model, the driver chip includes an LED button control unit, the LED button control unit includes a plurality of column signal output ports, the same number of pull-down resistors as the column signal output ports, and a plurality of row signal output ports, each column signal output port is connected to the first end of the respective corresponding pull-down resistor, and the second end of each of the pull-down resistors is grounded.

[0007] In a third aspect, an embodiment of the utility model provides a circuit control board, and the control circuit described in any one of the embodiments of the utility model is arranged on the circuit control board.

[0008] In a fourth aspect, an embodiment of the utility model provides an electronic device, comprising the circuit control board described in any one of the embodiments of the utility model.

[0009] As described above, the embodiment of the utility model provides an LED display and key multiplexing circuit, a control circuit, a control board and an electronic device. The embodiment of the utility model sets at least one scanning branch, each scanning branch includes a first number of LED units and a second number of key units, the positive terminal of the LED unit in the same scanning branch and the first end of the key unit are used to connect to the same column signal output port in the driver chip, each column signal output port in the driver chip is connected to a grounded pull-down resistor, the positive terminal of the LED unit in different scanning branches and the first end of the key unit are used to connect to different column signal output ports in the driver chip, the negative terminal of the LED unit in the same scanning branch is used to connect to different row signal output ports in the driver chip, and the second end of the key unit in the same scanning branch is used to connect to different row signal output ports in the driver chip. The multiplexing of the row and column signal output ports of the driver chip is realized, and the LED unit scanning and the key scanning of the same number as the LED unit can be supported, and the main control chip does not need to provide an additional I / O interface for key scanning, which effectively reduces the number of I / O interfaces of the main control chip and reduces the cost of the main control chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A circuit schematic diagram of an LED display and key multiplexing circuit provided by an embodiment of the utility model;

[0011] Figure 2 A circuit schematic diagram of another LED display and key multiplexing circuit provided by an embodiment of the utility model;

[0012] Figure 3 A circuit schematic diagram of another LED display and key multiplexing circuit provided by an embodiment of the utility model;

[0013] Figure 4 A schematic diagram of the structure of a control circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0014] In order to make the technical problems solved by the utility model, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the utility model are further described in detail below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0015] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0016] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0017] Figure 1 The schematic diagram of the structure of a LED display and key multiplexing circuit provided by the embodiment of the utility model. Figure 1As shown, the LED display and key multiplexing circuit includes at least one scanning branch 100, each scanning branch 100 includes a first number of LED units 101 and a second number of key units 102, the positive terminal of the LED unit 101 and the first end of the key unit 102 in the same scanning branch 100 are used to connect to the same column signal output port in the driver chip, each column signal output port in the driver chip is connected to a grounded pull-down resistor, the positive terminal of the LED unit 101 and the first end of the key unit 102 in different scanning branches 100 are used to connect to different column signal output ports in the driver chip, the negative terminal of the LED unit 101 in the same scanning branch 100 is used to connect to different row signal output ports in the driver chip, and the second end of the key unit 102 in the same scanning branch 100 is used to connect to different row signal output ports in the driver chip.

[0018] Among them, the number of LED units and key units in the LED display and key multiplexing circuit can be set to adapt to the actual application scenario requirements and the row and column signal output ports that the driver chip can provide. Specifically, the first number can be greater than or equal to 0, the second number can be greater than or equal to 0, and the first number and the second number are not 0 at the same time. Correspondingly, the scanning branch can be only provided with LED units or key units, or LED units and key units can be provided at the same time. In one embodiment, for a certain scanning branch, when the first number is 0 and the second number is greater than 0, the scanning branch can only provide key scanning function. In one embodiment, for a certain scanning branch, when the first number is greater than 0 and the second number is 0, the scanning branch can only provide LED control function. In one embodiment, for a certain scanning branch, when the first number is greater than 0 and the second number is greater than 0, the scanning branch can simultaneously realize key scanning and LED control functions. Figure 1An example driver chip is given, which includes column signal output ports PA0-PA23 and row signal output ports PB0-PB15, and can support scanning of up to 16×24 LED units and up to 16×24 key units. Accordingly, the LED display and key multiplexing circuit can include up to 24 scanning branches, each of which can be provided with a first number of LED units and key units. In order to ensure independent scanning control of each LED unit and key unit, the number of LED units in each scanning branch cannot exceed 16, and the number of key units in each scanning branch cannot exceed 16. Among them, the LED unit 101 can be composed of at least one LED lamp, the LED unit 101 can be used for luminous image display, and the key unit 102 can be used for key detection. The positive terminal of the LED unit 101 and the first end of the key unit 102 in the same scanning branch 100 are used to connect to the same any port of the column signal output ports PA0-PA23 of the driver chip, so as to ensure that the LED unit 101 and the key unit 102 in the same scanning branch 100 are controlled by the same column signal output port, and the column signal output ports PA0-PA23 of the driver chip are respectively connected to the pull-down resistors R201-R224, and the pull-down resistors are grounded. The positive terminal of the LED unit 101 and the first end of the key unit 102 in different scanning branches 100 are used to connect to different column signal output ports in the driver chip, so as to ensure that the LED unit 101 and the key unit 102 in each scanning branch 100 are controlled by different column signal output ports. The negative terminal of the LED unit 101 in the same scanning branch 100 is used to connect to different row signal output ports PB0-PB15 in the driving chip, so as to ensure that the LED unit 101 in the same scanning branch 100 can be respectively controlled by different row signal output ports, and the second end of the key unit 102 in the same scanning branch 100 is used to connect to different row signal output ports in the driving chip, so as to ensure that the key unit 102 in the same scanning branch 100 can be respectively controlled by different row signal output ports.

[0019] As mentioned above, the LED display and key multiplexing circuit in the embodiment of the utility model is configured by setting at least one scanning branch, each scanning branch includes a first number of LED units and a second number of key units, the positive terminal of the LED unit in the same scanning branch and the first end of the key unit are used to connect to the same column signal output port in the driver chip, each column signal output port in the driver chip is connected to a grounded pull-down resistor, the positive terminal of the LED unit in different scanning branches and the first end of the key unit are used to connect to different column signal output ports in the driver chip, the negative terminal of the LED unit in the same scanning branch is used to connect to different row signal output ports in the driver chip, and the second end of the key unit in the same scanning branch is used to connect to different row signal output ports in the driver chip, so that the driver chip can support LED unit scanning and key scanning of the same number as the LED units, without the need for the main control chip to provide an additional I / O interface for key scanning, effectively reducing the number of I / O interfaces of the main control chip, reducing wiring, simplifying the PCB board, and reducing the cost of the main control chip.

[0020] In one embodiment, Figure 2 A schematic diagram of another LED display and key multiplexing circuit provided by an embodiment of the utility model, wherein: Figure 2 An example driver chip is given, which includes column signal output ports PA0-PA23 and row signal output ports PB0-PB15, and can support scanning of 16×24 LED units and 16×24 key units. Figure 2 As shown, each LED unit 101 includes an LED lamp, each key unit 102 may include a key and a diode, the first end of the keys in the same scanning branch is used to connect to the same any port among the column signal output ports PA0-PA23 of the driver chip, the first ends of the keys in different scanning branches are used to connect to different column signal output ports among the column signal output ports PA0-PA23 of the driver chip, the second ends of the keys in the same key unit are connected to the cathode end of the diode, and the anode end of the diode in the same scanning branch is used to connect to different row signal output ports among the row signal output ports PB0-PB15 of the driver chip.

[0021] Among them, Figure 2As shown, the first scanning branch can be composed of LED lamp L101, LED lamp L116, switch K1011 and diode D1011. In the specific implementation process, taking the control of LED lamp L101 lighting up as an example, the column signal output port PA0 of the driver chip is set high, the other column signal output ports PA1-PA23 are set low or suspended, the row signal output port PB0 is set low, and the other row signal output ports PB1-PB15 are set high or suspended, the LED lamp L101 is turned on and lights up, and the other LED lamps are not lit. Taking the detection button K1011 as an example, the row signal output port PB0 of the driver chip is set high, and the column signal output port PA0 is pulled down by the pull-down resistor R201 grounded. When the button K1011 is triggered, the branch where the button K1011 is located is turned on, and the pull-down resistor R201 shares most of the voltage drop, so that the column signal output port PA0 can detect a high level. Therefore, by using the time-division scanning method, when in the LED control period, the high state of the column signal output port of the control driver chip and the low state of the row signal output port can be controlled according to the lighting requirements of the LED lamp. When in the key detection period, the row signal output ports of the driver chip can all be set high, and the column signal output ports can all be set low, and the trigger state of the key can be determined by row scanning.

[0022] In one embodiment, Figure 2 As shown, each scanning branch also includes a first resistor, the first end of the first resistor in the same scanning branch is connected to the positive end of the LED unit in the scanning branch, the second end of the first resistor in the same scanning branch is used to connect to the column signal output port in the driver chip, and the second end of the first resistor in different scanning branches is used to connect to different column signal output ports in the driver chip.

[0023] Among them, multiple scanning branches are respectively provided with first resistors R101-R124. The first resistor R101 of the first scanning branch is set between the column signal output port PA0 of the driving chip and the positive ends of the LED lamps L101 and L116 of the scanning branch, which can be used to control the voltage drop of the LED lamp, which is beneficial to the normal emission of the LED lamp.

[0024] Optionally, the color of the LED units in the same scanning branch is the same, and the color of the LED units in adjacent different scanning branches is different. Since the voltage drops corresponding to LED lights of different colors are different, different first resistors need to be configured. In addition, for the same LED light, the brightness of the LED light can be controlled by controlling the duty cycle of the signal. Thus, the LED display and key multiplexing circuit can support the display of LED lights of different colors, providing different color options for the pattern.

[0025] In one embodiment, Figure 2As shown, the LED display and key multiplexing circuit also includes second resistors having the same number as the row signal output ports in the driver chip, the first ends of different second resistors are used to connect to different row signal output ports in the driver chip, and the second end of each second resistor is connected to the second end of the key unit for connecting to the row signal output port corresponding to the second resistor.

[0026] The second resistors R301-R316 are respectively connected to the row signal output ports PB0-PB15 of the driver chip. By setting the second resistors, the LED lights of the same scan branch can be prevented from being dimly lit when the key is pressed and triggered, thereby reducing abnormal display of the LED lights.

[0027] In one embodiment, Figure 3 A structural schematic diagram of another LED display and button multiplexing circuit provided for an embodiment of the utility model, wherein the LED unit in the scanning branch includes a red LED unit, a green LED unit and a blue LED unit, and the red LED unit, green LED unit and blue LED unit in adjacent different scanning branches constitute at least one light-emitting unit 103.

[0028] Among them, Figure 3 As shown, LED lamp L101 can be a red LED unit, LED lamp L201 can be a green LED unit, LED lamp L301 can be a blue LED unit, and LED lamp L101, LED lamp L201 and LED lamp L301 can form a light-emitting unit 103. Optionally, the resistance values ​​of the first resistors of the scanning branches corresponding to the red LED unit, the green LED unit and the blue LED unit in each light-emitting unit 103 are set based on a preset proportional relationship, so that the light-emitting unit 103 outputs white light when working normally, and the light-emitting unit 103 can also emit different lights according to the different voltages output by its corresponding column signal output port. For example, one of the light-emitting units 103 can emit different colors of light according to the different voltages output by the column signal output port PA0, the column signal output port PA8 and the column signal output port PA16. Therefore, in addition to emitting the color light of each LED unit, the light-emitting unit 103 can also emit different colors of light in combination, including white light, which is lower in cost than directly using LED lamps of different colors or white light LED lamps.

[0029] The utility model embodiment also provides a control circuit, which includes a driver chip and any one of the LED display and key multiplexing circuits in the above embodiments, the driver chip includes an LED key control unit, the LED key control unit includes a plurality of column signal output ports, a pull-down resistor with the same number as the column signal output ports, and a plurality of row signal output ports, each column signal output port is connected to the first end of the respective corresponding pull-down resistor, and the second end of each pull-down resistor is grounded. It should be noted that the driver chip can be controlled by the main control chip, and the LED key control unit can be used to control the LED display and scan the user's key status. It can be understood that other components on the control circuit are not specifically limited in this embodiment. The control circuit has corresponding functions and beneficial effects as the LED display and key multiplexing circuit provided in any of the above embodiments.

[0030] Optional, Figure 4 A schematic diagram of a control circuit provided by an embodiment of the utility model is shown in FIG. Figure 4 As shown, the control circuit 200 also includes a crystal oscillator 202, and the driver chip 201 also includes a control unit 2011, a time management module 2013 and a buffer memory 2014, wherein the time management module 2013, the buffer memory 2014 and the LED button control unit 2012 are connected to the control unit 2011, and the time management module 2013 is connected to the crystal oscillator 202.

[0031] Among them, the control unit 2011 can be used to implement the internal control logic of the driver chip 201, which can be specifically an IC (Integrated Circuit), an MCU (Microcontroller Unit) and a logic control unit, etc. The buffer memory 2014 can be used to store key information, LED display buffer, etc., which can be specifically an SRAM (Static Random-Access Memory), a ferroelectric memory, a DRAM (Dynamic Random-Access Memory), etc. The time management module 2013 can be composed of an RTC unit (Real-Time Clock) and an RCC unit (Reset and Clock Control). The crystal oscillator 202 can be an ordinary crystal oscillator, an RTC crystal oscillator, etc. The embodiment of the utility model also provides a circuit control board, and the above-mentioned control circuit is arranged on the circuit control board. The control circuit of the circuit control board has corresponding functions and beneficial effects with the LED display and key multiplexing circuit provided in any of the above embodiments. Optionally, the current control board can be a PCB board or other electronic component integration method, which is not limited in this application.

[0032] Optionally, the time management module 2013 can realize the perpetual calendar function, and the perpetual calendar can be built into the driver chip 201, so that the driver chip 201 does not need an external perpetual calendar module, so that the control circuit has the functions of perpetual calendar display, key scanning control, LED control, etc.

[0033] The embodiment of the utility model further provides an electronic device, comprising the above-mentioned circuit control board. The circuit control board of the electronic device and the LED display and key multiplexing circuit provided in any of the above-mentioned embodiments have corresponding functions and beneficial effects.

[0034] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the utility model. It should be understood that the above are only specific embodiments of the utility model and are not intended to limit the protection scope of the utility model. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An LED display and key multiplexing circuit, characterized in that: include: At least one scanning branch, each of the scanning branches includes a first number of LED units and a second number of key units, the positive terminal of the LED unit and the first end of the key unit in the same scanning branch are used to connect to the same column signal output port in the driver chip, each column signal output port in the driver chip is connected to a grounded pull-down resistor, the positive terminal of the LED unit and the first end of the key unit in different scanning branches are used to connect to different column signal output ports in the driver chip, the negative terminal of the LED unit in the same scanning branch is used to connect to different row signal output ports in the driver chip, and the second end of the key unit in the same scanning branch is used to connect to different row signal output ports in the driver chip.

2. The LED display and key multiplexing circuit according to claim 1 is characterized in that: Each of the scanning branches also includes a first resistor, the first end of the first resistor in the same scanning branch is connected to the positive end of the LED unit in the scanning branch, the second end of the first resistor in the same scanning branch is used to connect to the column signal output port in the driving chip, and the second end of the first resistor in different scanning branches is used to connect to different column signal output ports in the driving chip.

3. The LED display and key multiplexing circuit according to claim 2 is characterized in that: The colors of the LED units in the same scanning branch are the same, and the colors of the LED units in different adjacent scanning branches are different.

4. The LED display and key multiplexing circuit according to claim 3 is characterized in that: The LED units in the scanning branches include a red LED unit, a green LED unit and a blue LED unit, and the red LED units, green LED units and blue LED units in different adjacent scanning branches form at least one light-emitting unit.

5. The LED display and key multiplexing circuit according to claim 4 is characterized in that: The resistance values ​​of the first resistors of the scanning branches respectively corresponding to the red LED unit, the green LED unit and the blue LED unit in each of the light-emitting units are set based on a preset proportional relationship, so as to enable the light-emitting unit to output white light when working normally.

6. The LED display and key multiplexing circuit according to claim 1, characterized in that: The circuit also includes second resistors having the same number as the row signal output ports in the driver chip, the first ends of different second resistors are used to connect to different row signal output ports in the driver chip, and the second end of each second resistor is connected to the second end of the key unit used to connect to the row signal output port corresponding to the second resistor.

7. The LED display and key multiplexing circuit according to claim 1, characterized in that: Each of the key units includes a key and a diode. The first end of the keys in the same scanning branch is used to connect to the same column signal output port in the driving chip, the first end of the keys in different scanning branches is used to connect to different column signal output ports in the driving chip, the second end of the keys in the same key unit is connected to the cathode end of the diode, and the anode end of the diode in the same scanning branch is used to connect to different row signal output ports in the driving chip.

8. A control circuit, characterized in that: The control circuit includes a driving chip and an LED display and button multiplexing circuit as described in any one of claims 1 to 7, the driving chip includes an LED button control unit, the LED button control unit includes a plurality of column signal output ports, pull-down resistors having the same number as the column signal output ports, and a plurality of row signal output ports, each column signal output port is connected to a first end of a respective corresponding pull-down resistor, and a second end of each pull-down resistor is grounded.

9. The control circuit according to claim 8, characterized in that: The control circuit also includes a crystal oscillator, and the driving chip also includes a control unit, a time management module and a buffer memory. The time management module, the buffer memory and the LED button control unit are connected to the control unit, and the time management module is connected to the crystal oscillator.

10. A circuit control board, characterized in that: The control circuit as claimed in claim 9 is arranged on the circuit control board.

11. An electronic device, characterized in that: include: The circuit control board as claimed in claim 10.

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