CN221927076U - Key multiplexing circuit and terminal control device - Google Patents

Abstract

The utility model proposes a key multiplexing circuit and a terminal control device, wherein the key multiplexing circuit includes a first key, a first trigger module, a second trigger module and a delay module; the first key is connected to the first interface of the control chip through the first trigger module, the first key is also connected to the second interface of the control chip through the second trigger module, and the delay module is connected to the second trigger module. By setting the delay module, the second interface presents a different state after being triggered by the first key and other keys, thereby realizing the confirmation of the triggering of the first key, and at the same time, the delay module is only connected to the second trigger module, therefore, when the first interface related functions are executed by the first key, the first interface will not be affected by the delay module, thereby realizing the isolation of the functions between the first interface and the second interface, realizing key multiplexing, and ensuring the independence of the functions of each interface.

Description

Key multiplexing circuit and terminal control device

Technical Field

The utility model relates to the field of equipment control, in particular to a key multiplexing circuit and a terminal control device.

Background Art

In order to better realize taking photos or recording videos with a mobile phone, the prior art provides a method of controlling the shooting function of the mobile phone through a Bluetooth remote control; however, due to the size and cost of the Bluetooth remote control, the number of buttons that can be set in the Bluetooth remote control and the number of pins that can be provided by the chip in the Bluetooth remote control are relatively small. At the same time, some pins, such as power on and off, reset, software debugging and other basic functions, need to be guaranteed. Therefore, how to add new functions on this basis without affecting the original pin functions becomes a problem that needs to be solved.

Utility Model Content

The main purpose of the utility model is to provide a key multiplexing circuit and a terminal control device, aiming to solve the problem of how to add new functions without affecting the original pin functions in the prior art.

To achieve the above-mentioned purpose, the utility model provides a key multiplexing circuit, which is connected to a control chip; the key multiplexing circuit comprises a first key, a first trigger module, a second trigger module and a delay module; the first key is connected to a first interface of the control chip through the first trigger module, the first key is also connected to a second interface of the control chip through the second trigger module, and the delay module is connected to the second trigger module; wherein:

The first trigger module is used to send a target level signal to the control chip when the first button is triggered;

The second trigger module is used to send a target level signal to the control chip when the first button is triggered;

The delay module is used to maintain the target level state of the second trigger module within the delay time after the first button is triggered.

Optionally, the first trigger module includes a first pull-up unit and a first low-level trigger unit; the first pull-up unit is connected to the first interface of the control chip, and the first low-level trigger unit is connected between the first interface of the control chip and the first button; wherein:

The first pull-up unit is used to output a high level to the first interface of the control chip;

The first low-level trigger unit is used to output a low level to the first interface of the control chip when the first button is triggered.

Optionally, the pull-up unit includes a first resistor, and the low-level trigger unit includes a first diode; wherein:

A first end of the first resistor is connected to a power supply, and a second end of the first resistor is connected to a first interface of the control chip;

The anode of the first diode is connected to the first interface of the control chip, and the cathode of the first diode is grounded through the first button.

Optionally, the second trigger module includes a second pull-up unit and a second low-level trigger unit; the second pull-up unit is connected to the second interface of the control chip, and the second low-level trigger unit is connected between the second interface of the control chip and the first button; wherein:

The second pull-up unit is used to output a high level to the second interface of the control chip;

The second low-level trigger unit is used to output a low level to the second interface of the control chip when the first button is triggered.

Optionally, the pull-up unit includes a second resistor, and the low-level trigger unit includes a second diode; wherein:

A first end of the second resistor is connected to a power supply, and a second end of the second resistor is connected to a second interface of the control chip;

The anode of the second diode is connected to the second interface of the control chip, and the cathode of the second diode is grounded through the first button.

Optionally, the first diode and the second diode are Schottky diodes.

Optionally, the delay module includes a first capacitor; wherein:

A first end of the first capacitor is connected to the second interface of the control chip, and a second end of the first capacitor is grounded.

Optionally, the button multiplexing circuit further includes a second button and a third trigger module, and the second button is connected to the third interface of the control chip through the third trigger module; wherein:

The third trigger module is used to send a start signal to the control chip when the second button is triggered.

Optionally, the third trigger module includes a third resistor, a first end of the third resistor is connected to the power supply, a second end of the third resistor is connected to the third interface of the control chip, and the second end of the third resistor is also grounded through the second button.

In addition, to achieve the above-mentioned purpose, the utility model also provides a terminal control device, which includes a control chip and the key multiplexing circuit as described above.

Optionally, the first interface of the control chip is a debugging interface, the second interface of the control chip is a power-on expansion interface, and the third interface of the control chip is a power-on/off interface.

The utility model proposes a key multiplexing circuit and a terminal control device, wherein the key multiplexing circuit is connected to a control chip; the key multiplexing circuit includes a first key, a first trigger module, a second trigger module and a delay module; the first key is connected to the first interface of the control chip through the first trigger module, the first key is also connected to the second interface of the control chip through the second trigger module, and the delay module is connected to the second trigger module. By setting the delay module, the state of the second interface is different after being triggered by the first key and other keys, thereby realizing the confirmation of the triggering of the first key. At the same time, the delay module is only connected to the second trigger module. Therefore, when the first interface related functions are executed by the first key, the first interface will not be affected by the delay module, thereby realizing the isolation of functions between the first interface and the second interface, realizing key multiplexing, and ensuring the independence of the functions of each interface.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

FIG1 is a functional module diagram of an embodiment of a key multiplexing circuit of the utility model;

FIG2 is a circuit structure diagram of the key multiplexing circuit of the utility model applied in the embodiment of FIG1 ;

FIG3 is a functional module diagram of another embodiment of a key multiplexing circuit of the present invention;

FIG. 4 is a flow chart of a terminal control method applied to a key multiplexing circuit according to the present invention.

The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

Description of Figure Numbers:

Label name Label name 110 First button R1～R3 First resistor to third resistor 120 Second button D1～D2 First diode to second diode 210 The first trigger module K1～K2 First button～Second button 220 Second trigger module C1 First capacitor 230 The third trigger module 300 Delay Module

DETAILED DESCRIPTION

It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

The utility model provides a key multiplexing circuit, which is applied to a terminal control device. Please refer to Figure 1, which is a functional module diagram of an embodiment of the key multiplexing circuit of the utility model. In this embodiment, the key multiplexing circuit is connected to a control chip; the key multiplexing circuit includes a first key K1, a first trigger module 110, a second trigger module 120 and a delay module 200; the first key K1 is connected to the first interface of the control chip through the first trigger module 110, the first key K1 is also connected to the second interface of the control chip through the second trigger module 120, and the delay module 200 is connected to the second trigger module 120; wherein:

The first trigger module 110 is used to send a target level signal to the control chip when the first button K1 is triggered;

The second trigger module 120 is used to send a target level signal to the control chip when the first button K1 is triggered;

The delay module 200 is used to maintain the target level state of the second trigger module 120 within the delay time after the first button K1 is triggered.

The specific model of the control chip can be set based on actual application needs, such as the low-power Bluetooth chip DA14531; when the control chip is DA14531, the first interface can be the P05 pin of DA14531, the second interface can be the P07 pin of DA14531, and the third interface described later can be the P02 pin of DA14531.

Different interfaces of the control chip execute their corresponding functions; specific functions can be set based on actual needs, such as the first interface is used for camera shutter and software debugging, the second interface is used for power-on expansion, and the third interface described later is used for power on, power off and reset; among them, the power-on expansion function is used to trigger the expansion operation set again after the power-on is triggered. If the power-on expansion function specifically includes power-on and photo taking, then after the second interface is triggered, the power-on operation is performed first, and then the photo taking operation is performed, that is, one trigger of the second interface performs two different operations. The above functions will be explained later.

Based on the specific structure and setting of the first button K1, the corresponding triggering state is different, such as being triggered when the button is pressed, or being triggered when the button is long pressed. This embodiment and subsequent embodiments are described by taking the first button K1 being triggered when being pressed as an example.

The target level signal is the signal corresponding to when the first key K1 is triggered; if the interface of the control chip is at a high level in an idle state and at a low level when the corresponding key is pressed, the low level is the target level signal.

The target level state refers to the state of the interface of the control chip outputting the target level signal; for example, when the first button K1 is triggered, the first trigger module 110 and the second trigger module 120 are in the target level state, the first trigger module 110 outputs the target level signal to the first interface of the control chip, and the second trigger module 120 outputs the target level signal to the second interface of the control chip; generally, when the button is released from the trigger state, if the button is pressed, it is triggered, and if the button is released, it is released from the trigger, after the release of the trigger, the corresponding trigger module releases the target level state and stops outputting the target level signal to the control chip; and in this embodiment, a delay module 200 is provided to maintain the target level state of the second trigger module 120, that is, within the delay time after the first button K1 is released, the second trigger module 120 is still in the target level state, and still outputs the target level signal to the second interface of the control chip, and after the delay time has passed, the second trigger module 120 releases the target level state and stops outputting the target level signal to the control chip.

At the same time, since the delay module 200 is only configured to be connected to the second trigger module 120, the state change of the first trigger module 110 caused by the first button K1 will not be affected by the delay module 200, and the first trigger module 110 can implement single-click, double-click, long press and other operations based on the triggering of the first button K1; that is, in the circuit structure of this embodiment, the first trigger module 110 can still ensure the realization of its own functions.

This embodiment sets a delay module so that after being triggered by the first button and other buttons, the second interface presents a different state, thereby realizing confirmation of the triggering of the first button. At the same time, the delay module is only connected to the second trigger module. Therefore, when the first interface related functions are executed by the first button, the first interface will not be affected by the delay module, thereby realizing isolation of functions between the first interface and the second interface, realizing button multiplexing and ensuring the independence of the functions of each interface.

Further, referring to FIG. 2 , the first trigger module 110 includes a first pull-up unit and a first low-level trigger unit; the first pull-up unit is connected to the first interface of the control chip, and the first low-level trigger unit is connected between the first interface of the control chip and the first button K1; wherein:

The first pull-up unit is used to output a high level to the first interface of the control chip;

The first low-level trigger unit is used to output a low level to the first interface of the control chip when the first button K1 is triggered.

In this embodiment, the high level is set as the signal output by the first trigger unit to the control module in a non-target level state, and the low level is set as the target level signal output by the first trigger unit to the control module in a target level state.

When the first button K1 is not triggered, the first pull-up unit maintains the first interface of the control chip at a high level; when the first button K1 is triggered, the first low-level trigger unit outputs a low level to the first interface of the control chip.

Further, the pull-up unit includes a first resistor R1, and the low-level trigger unit includes a first diode D1; wherein:

A first end of the first resistor R1 is connected to a power supply, and a second end of the first resistor R1 is connected to a first interface of the control chip;

An anode of the first diode D1 is connected to the first interface of the control chip, and a cathode of the first diode D1 is grounded through the first button K1.

When the first button K1 is not triggered, the first diode D1 is not conducting, the voltage of the power supply is output to the first interface of the control chip through the first resistor R1, and the first interface presents a high level;

When the first button K1 is triggered, the first diode D1 is forward-conducted, the first interface of the control chip is grounded through the first diode D1 , and the first interface of the control chip presents a low level.

Further, the second trigger module 120 includes a second pull-up unit and a second low-level trigger unit; the second pull-up unit is connected to the second interface of the control chip, and the second low-level trigger unit is connected between the second interface of the control chip and the first button K1; wherein:

The second pull-up unit is used to output a high level to the second interface of the control chip;

The second low-level trigger unit is used to output a low level to the second interface of the control chip when the first button K1 is triggered.

In this embodiment, the high level is set as the signal output by the second trigger unit to the control module in a non-target level state, and the low level is set as the target level signal output by the second trigger unit to the control module in a target level state.

When the second button K2 is not triggered, the second pull-up unit maintains the second interface of the control chip at a high level; when the second button K2 is triggered, the second low-level trigger unit outputs a low level to the second interface of the control chip.

Further, the pull-up unit includes a second resistor R2, and the low-level trigger unit includes a second diode D2; wherein:

A first end of the second resistor R2 is connected to a power supply, and a second end of the second resistor R2 is connected to a second interface of the control chip;

The anode of the second diode D2 is connected to the second interface of the control chip, and the cathode of the second diode D2 is grounded through the first button K1.

When the second button K2 is not triggered and is in a non-target level state, the second diode D2 is not conducting, the voltage of the power supply is output to the second interface of the control chip through the second resistor R2, and the second interface presents a high level;

When the second button K2 is triggered, the second diode D2 is forward-conducted, the second interface of the control chip is grounded through the second diode D2, and the second interface of the control chip presents a low level.

Furthermore, the first diode D1 and the second diode D2 are Schottky diodes.

It can be understood that although the interface of the control chip is grounded through the diode after the diode is forward grounded, due to the existence of the diode voltage drop, the actual potential of the interface of the control chip is the voltage drop of the diode; it can be understood that the voltage drop of a general diode is 0.7V, that is, if a general diode is used, then when the key is triggered, the interface of the control chip receives a low-level signal of 0.7V; however, in actual applications, terminal control devices such as Bluetooth remote controls are powered by button batteries with a small power supply voltage, and the maximum value of the low level recognized by the control chip is usually 0.3 times the power supply voltage, that is, the low-level voltage generally needs to be less than 0.45V; and the 0.7V voltage drop of a general diode obviously does not meet the low-level requirements, therefore, a Schottky diode is used in this embodiment; Schottky diodes have the characteristics of low voltage drop, generally, the voltage drop of Schottky diodes is 0.07V, which meets the requirements for low-level voltage, that is, when the key is triggered, the corresponding interface of the control chip will be clamped at 0.07V by the Schottky diode.

Furthermore, the delay module 200 includes a first capacitor C1; wherein:

A first end of the first capacitor C1 is connected to the second interface of the control chip, and a second end of the first capacitor C1 is grounded.

When the first button K1 is not triggered, the first capacitor C1 is charged by the power supply. After the charging is completed, the voltage of the first capacitor C1 is the power supply voltage.

When the first button K1 is triggered, the second diode D2 is turned on, and the second interface of the control chip is clamped to 0.07V, that is, the second trigger module 120 outputs a target level signal, and the first capacitor C1 is discharged to the ground through the second diode D2;

When the first button K1 is released, the second diode D2 is turned off, and due to the existence of the first capacitor C1, the second interface voltage of the control chip cannot change suddenly. As the first capacitor C1 is charged, the second interface voltage of the control chip gradually rises. When it rises to 0.45V, that is, a high level, the second trigger module 120 releases the target level state and stops outputting the target level signal. The specific values of the voltage in this embodiment are only for example. In actual applications, analog execution can be set based on actual circuit components.

Further, referring to FIG. 3 , the key multiplexing circuit further includes a second key K2 and a third trigger module 130 , and the second key K2 is connected to the third interface of the control chip through the third trigger module 130 ; wherein:

The third trigger module 130 is used to send a start signal to the control chip when the second button K2 is triggered.

Based on the specific structure and setting of the second button K2, the corresponding trigger state is different, such as being triggered when the button is pressed, or being triggered when the button is long pressed. This embodiment and subsequent embodiments are described by taking the triggering of the second button K2 when being pressed as an example.

The start signal is the corresponding signal when the second button K2 is triggered; if the third interface of the control chip is at a high level in the idle state and at a low level when the corresponding button is pressed, the low level is the start signal. The start state refers to the state of the interface that outputs the start signal to the control chip.

When the second button K2 is triggered, the third trigger module 130 is in an activated state, and the third trigger module 130 outputs an activation signal to the third interface of the control chip.

Since the second trigger module 120 is provided with a delay module 200, while the third trigger module 130 is not provided with a delay module, the states of the second interface and the third interface are different during the delay time; therefore, the trigger button can be determined by the state of the interface; for example, when the trigger is triggered by the first button K1, the delay module 200 maintains the target level state of the second trigger module 120, so that after the button is released, the control chip can obtain the target level signal from the second interface; and when the trigger is triggered by the second button K2, the first trigger module 110 and the second trigger module 120 are in a state of a predetermined level. 0 will not be triggered, and no target level signal will be output throughout the process. The third trigger module 130 triggers the target level signal to the third interface. After the button is released, since the second trigger module 120 itself is not in the target level state, the delay module 200 cannot maintain the target level state of the second trigger module 120, and the control chip cannot receive the target level signal at the second interface; therefore, when the control chip receives the target level signal at the second interface, it can determine that this trigger is triggered by the first button K1. When the second interface does not receive the target level signal, it can determine that this trigger is triggered by the second button K2.

Furthermore, the third trigger module 130 includes a third resistor R3, a first end of the third resistor R3 is connected to the power supply, a second end of the third resistor R3 is connected to the third interface of the control chip, and a second end of the third resistor R3 is also grounded through the second button K2.

When the second button K2 is not triggered, the voltage of the power supply is output to the third interface of the control chip through the third resistor R3, and the third interface of the control chip is at a high level;

When the second button K2 is triggered, the second end of the third resistor R3 is grounded, and the third interface of the control chip is at a low level.

The utility model also protects a terminal control device, which includes a control chip and a key multiplexing circuit. The structure of the key multiplexing circuit can refer to the above embodiment and will not be repeated here. As a matter of course, since the terminal control device of this embodiment adopts the technical solution of the key multiplexing circuit, the terminal control device has all the beneficial effects of the key multiplexing circuit.

Furthermore, the first interface of the control chip is a debugging/camera shutter interface, the second interface of the control chip is a power-on expansion interface, and the third interface of the control chip is a power on/off/reset interface.

The utility model also provides a terminal control method. Referring to FIG. 4 , the terminal control method is applied to the terminal control device as described above. The terminal control method includes:

Step S10, if the terminal control device triggers wake-up, then obtain the signal state of the second interface of the control chip;

Step S20, determining whether the trigger button for the current wake-up is the first button or the second button according to the signal state of the second interface;

Step S30, executing a power-on operation corresponding to the trigger button.

In this embodiment, on the basis of the first interface and the third interface, the function setting of the second interface is added; specifically, the first interface is a debugging interface and a reset interface, that is, the first interface is used for software debugging and resetting; the third interface is a power on/off interface, that is, the third interface is used for power on and off. On this basis, in this embodiment, a second interface is set, and the second interface is a power on/off expansion interface, that is, the second interface is used to perform power on + expansion operations, that is, trigger the power on and then perform additional operations of expansion, that is, the second interface includes multiple operations including power on and expansion operations.

The signal status is used to indicate whether the interface receives the target level signal or the start signal; from the above description of the key multiplexing circuit, it can be seen that based on the signal status of the second interface, it can be determined whether the trigger key is the first key or the second key, and the details will not be repeated.

It can be seen from the function settings of the first interface, the second interface, and the third interface that the present embodiment includes two power-on modes, namely, the functions corresponding to the second interface and the third interface; when the terminal control device is in sleep or powered off, if the first button is pressed, the first interface and the second interface output a target level signal to the control chip. Since the second interface has a power-on function, the control chip is awakened at this time. At the same time, based on the signal state of the second interface, it is determined that the first button is triggered, and the extended operation corresponding to the second interface is executed;

When the terminal control device is in sleep or shutdown, if the second button is pressed, the third interface outputs a startup signal to the control chip. Since the third interface has a power-on function, the control chip is awakened at this time. At the same time, based on the signal state of the second interface, it is determined that the second button is triggered to complete the power-on operation.

That is, this embodiment realizes a quick selection between simple startup and startup expansion based on the first button and the second button when the terminal control device is in sleep or shutdown, thereby improving the efficiency of implementing some functions.

Further, step S20 includes:

Step S21, determining whether the signal state of the second interface is a high level or a low level;

Step S22, if the signal state of the second interface is high level, the trigger button is the second button;

Step S23: if the signal state of the second interface is a low level, the trigger button is the first button.

Based on the example of the aforementioned key multiplexing circuit, when a low level is used as the target level signal, it can be determined whether the trigger key is the first key or the second key based on the high and low levels.

Furthermore, the step S30 includes:

Step S31, if the trigger button is the first button, establishing a communication connection with the associated terminal;

Step S32: sending a photographing instruction to the associated terminal, so that the associated terminal performs a photographing operation based on the photographing instruction.

Most existing mobile phones have cancelled the 3.5mm audio interface. Therefore, the general selfie stick that triggers taking pictures through the audio interface cannot be used. In order to solve this problem, a Bluetooth remote control wirelessly connected to the mobile phone can be set to realize the control of shooting. However, when the Bluetooth remote control is dormant or turned off, it is necessary to wake up the Bluetooth remote control first, and then press the photo button to realize taking pictures. Some scenes are fleeting. By the time a series of actions such as pressing the power button, waking up the Bluetooth remote control, pressing the photo button, and executing the photo operation are completed, the best shooting opportunity may have been missed. Therefore, in this embodiment, the function of the second interface is set to automatically take pictures when the power is turned on, that is, when the second interface triggers the terminal control device to wake up, the photo function is automatically triggered after the power is turned on, and the user does not need to wait for wakeup and press the photo button again, thereby realizing the rapid execution of the Bluetooth remote control from dormancy to power on and taking pictures.

The specific implementation method from powering on to taking pictures can be set based on the actual scenario; in this embodiment, the terminal control device establishes a communication connection with the associated terminal in advance so that automatic connection can be achieved when the device is powered on; after being awakened, the terminal control device automatically establishes a Bluetooth connection with the associated terminal, and after the connection is completed, it sends a picture taking instruction to the associated terminal, and the associated terminal executes the picture taking operation after receiving the picture taking instruction.

It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or system including the element. The serial numbers of the above-mentioned embodiments of the utility model are for description only and do not represent the advantages and disadvantages of the embodiments.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims (11)

1. The key multiplexing circuit is characterized by being connected with a control chip; the key multiplexing circuit comprises a first key, a first trigger module, a second trigger module and a delay module; the first key is connected with a first interface of the control chip through the first trigger module, the first key is also connected with a second interface of the control chip through the second trigger module, and the delay module is connected with the second trigger module; wherein:

the first trigger module is used for sending a target level signal to the control chip when the first key is triggered;

The second triggering module is used for sending a target level signal to the control chip when the first key is triggered;

And the delay module is used for maintaining the target level state target level signal of the second trigger module in the delay time after the first key is triggered.

2. The key multiplexing circuit of claim 1, wherein the first trigger module comprises a first pull-up unit and a first low level trigger unit; the first pull-up unit is connected with a first interface of the control chip, and the first low-level triggering unit is connected between the first interface of the control chip and the first key; wherein:

The first pull-up unit is used for outputting a high level to a first interface of the control chip;

The first low level triggering unit is used for outputting a low level to a first interface of the control chip when the first key is triggered.

3. The key multiplexing circuit of claim 2, wherein the pull-up unit comprises a first resistor and the low-level triggering unit comprises a first diode; wherein:

the first end of the first resistor is connected with a power supply, and the second end of the first resistor is connected with a first interface of the control chip;

The positive electrode of the first diode is connected with the first interface of the control chip, and the negative electrode of the first diode is grounded through the first key.

4. The key multiplexing circuit of claim 1, wherein the second trigger module comprises a second pull-up unit and a second low level trigger unit; the second pull-up unit is connected with a second interface of the control chip, and the second low-level triggering unit is connected between the second interface of the control chip and the first key; wherein:

the second pull-up unit is used for outputting a high level to a second interface of the control chip;

the second low level triggering unit is used for outputting a low level to a second interface of the control chip when the first key is triggered.

5. The key multiplexing circuit of claim 4, wherein the pull-up unit comprises a second resistor and the low-level triggering unit comprises a second diode; wherein:

The first end of the second resistor is connected with a power supply, and the second end of the second resistor is connected with a second interface of the control chip;

The positive pole of the second diode is connected with the second interface of the control chip, and the negative pole of the second diode is grounded through the first key.

6. The key multiplexing circuit of claim 3 or 5, wherein the first diode and the second diode are schottky diodes.

7. The key multiplexing circuit of claim 5, wherein said delay module comprises a first capacitor; wherein:

The first end of the first capacitor is connected with the second interface of the control chip, and the second end of the first capacitor is grounded.

8. The key multiplexing circuit of claim 1, further comprising a second key and a third trigger module, the second key being connected to a third interface of the control chip through the third trigger module; wherein:

The third triggering module is used for sending a starting signal to the control chip when the second key is triggered.

9. The key multiplexing circuit of claim 8, wherein the third trigger module comprises a third resistor, a first end of the third resistor is connected to a power supply, a second end of the third resistor is connected to a third interface of the control chip, and the second end of the third resistor is connected to ground through the second key.

10. A terminal control device, characterized in that it comprises a control chip and a key multiplexing circuit according to any one of claims 1-9.

11. The terminal control device of claim 10, wherein the first interface of the control chip is a debug/camera shutter interface, the second interface of the control chip is a power-on expansion interface, and the third interface of the control chip is a power-on/reset interface.