A functional multiplexing circuit and an electrical appliance

Abstract

The utility model relates to the field of power electronics, disclose a kind of function multiplexing circuit and electrical equipment, function multiplexing circuit includes main circuit;Main circuit includes temperature detection subcircuit, button and main LED lamp, temperature detection subcircuit includes the first resistance and thermistor of series connection;The input end of temperature detection subcircuit is connected with external power supply;The output end of temperature detection subcircuit is connected with ground wire;Button is shunt in thermistor both ends;The input end of temperature detection subcircuit is also connected with first chip end, and first chip end is a input output port of chip;The positive pole of main LED lamp is connected to the input end of temperature detection subcircuit, and the negative pole of main LED lamp is connected to second chip end, and second chip end is another input output port of chip, the utility model realizes chip IO mouth multifunction multiplexing, substantially reduce chip IO mouth occupancy, reduce chip resource consumption and hardware cost.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to a functional multiplexing circuit and electrical equipment. Background Technology

[0002] Small household appliances such as fans, electric heaters, and rice cookers need functions such as buttons, displays, and AD (Analog-to-Digital) temperature detection. Each function typically requires a chip I / O (Input / Output) port, thus consuming a significant number of chip I / O ports, resulting in high chip resource usage and cost. Therefore, it is necessary to optimize and upgrade the circuitry of electrical appliances to reduce the number of chip I / O ports required. Utility Model Content

[0003] In view of this, the present invention provides a function multiplexing circuit and electrical equipment to solve the problem of excessive occupation of chip I / O ports.

[0004] In a first aspect, this utility model provides a functional multiplexing circuit, including a main circuit; the main circuit includes a temperature detection sub-circuit, a button, and a main LED; the temperature detection sub-circuit includes a first resistor and a thermistor connected in series; the input terminal of the temperature detection sub-circuit is connected to an external power supply; the output terminal of the temperature detection sub-circuit is connected to ground; the button is connected in parallel across the thermistor; the input terminal of the temperature detection sub-circuit is also connected to a first chip terminal, which is an input / output port of the chip; the positive terminal of the main LED is connected to the input terminal of the temperature detection sub-circuit, and the negative terminal of the main LED is connected to a second chip terminal, which is another input / output port of the chip.

[0005] Based on the above technical means, by associating the temperature detection sub-circuit, the button and the main LED, three types of functions can be implemented by reusing two chip I / O ports. There is no need to allocate I / O ports separately for each function, which greatly reduces the chip I / O port occupation, reduces chip resource consumption and hardware costs, and simplifies the circuit structure.

[0006] In one optional implementation, when performing button detection and temperature detection, the first chip terminal is in an input state, and the second chip terminal outputs a high level; when performing main LED light detection, the first chip terminal outputs a high level, and the second chip terminal outputs a low level.

[0007] Based on the aforementioned technical means, the first chip terminal is in an input state, while the second chip terminal outputs a low level. This not only enables button detection and temperature detection but also prevents the LED from being lit, thus ensuring the accuracy of the button detection and temperature detection results. Conversely, the first chip terminal outputs a high level, while the second chip terminal outputs a low level. This enables LED detection while preventing power current from passing through the first chip terminal and short-circuiting the LED, ensuring that the LED lighting function is not conflicted, guaranteeing stable and accurate operation of all functions, and improving circuit reliability.

[0008] In one alternative implementation, the main circuit further includes a second resistor connected between the external power supply and the input of the temperature detection sub-circuit.

[0009] Based on the above technical means, adding a second resistor can limit the current input from the external power supply to the temperature detection sub-circuit, prevent excessive current from damaging components such as thermistors, extend the service life of the circuit, stabilize the circuit voltage, and improve the temperature detection accuracy.

[0010] In one optional implementation, the system further includes multiple extended main circuits, which have the same structure as the main circuit. In each extended main circuit, the input terminal of the temperature detection sub-circuit is connected to an extended first chip terminal, and the negative terminal of the main LED in each extended main circuit is connected to the second chip terminal.

[0011] Based on the above technical means, the expansion main circuit has the same structure as the main circuit. Only the expansion first chip is added to increase the number of functional modules. More temperature, button detection and LED display functions can be realized with a small increase in IO ports, which takes into account both functional expansion and IO port saving.

[0012] In one optional implementation, when either the main circuit or the extended main circuit performs button detection and temperature detection, the corresponding first chip terminal or the corresponding extended first chip terminal is in an input state, and the second chip terminal outputs a high level; when either the main circuit or the extended main circuit performs main LED detection, the corresponding first chip terminal or the corresponding extended first chip terminal outputs a high level, the remaining first chip terminals and / or the remaining extended first chip terminals that do not participate in the detection output a low level, and the second chip terminal outputs a low level.

[0013] Based on the aforementioned technical methods, the state of the chip terminals during the detection of the main circuit and extended main circuit is standardized to avoid signal interference caused by multiple circuits operating simultaneously. This ensures that each circuit completes the detection independently, in a time-sharing manner, and accurately. Only one main circuit is tested for button detection, temperature detection, and main LED detection at a time. Therefore, during button and temperature detection, only the corresponding first chip terminal or the corresponding extended first chip terminal is controlled as the input state, while the second chip terminal outputs a high level, enabling the corresponding main circuit to perform button and temperature detection. Furthermore, during main LED detection, the corresponding first chip terminal or the corresponding extended first chip terminal outputs a high level, while the other first chip terminals and / or other extended first chip terminals not involved in the detection output a low level, and the second chip terminal outputs a low level. This allows only the LEDs involved in the test to light up, while the others remain off, flexibly controlling the detection targets and improving the circuit's usability.

[0014] In one optional implementation, the main circuit and / or the extended main circuit further includes multiple secondary LEDs; wherein the positive terminal of each secondary LED is connected to the input terminal of the temperature detection sub-circuit in the corresponding main circuit, or to the input terminal of the temperature detection sub-circuit in the corresponding extended main circuit; the negative terminal of each secondary LED is connected to an extended second chip terminal; wherein the extended second chip terminals connected to multiple secondary LEDs located in the same main circuit or the same extended main circuit are different; and each extended second chip terminal is used for sharing a connection between a secondary LED in the main circuit and a secondary LED in a different extended main circuit.

[0015] Based on the above technical means, multiple auxiliary LEDs can be added to each main circuit or extended main circuit to participate in the test. Furthermore, each main circuit or extended main circuit has one auxiliary LED sharing an extended second chip terminal, eliminating the need to allocate a separate IO port for each auxiliary LED. This increases the number of LEDs displayed while reducing IO port usage, further optimizing IO port resource utilization and meeting the needs of multiple displays.

[0016] In one optional implementation, when any one of the secondary LEDs is being detected, the corresponding first chip terminal or the corresponding extended first chip terminal outputs a high level, the remaining first chip terminals and / or the remaining extended first chip terminals that are not involved in the detection output a low level, and the corresponding extended second chip terminal that is involved in the detection outputs a low level.

[0017] Based on the above technical means, the output state of the chip is clearly defined during the detection of the secondary LED, avoiding the influence of the chip signal that is not involved in the detection on the detection result, ensuring the accuracy of the detection of the secondary LED on / off state, and ensuring the stable realization of the multi-LED display function.

[0018] In one optional implementation, the function multiplexing circuit further includes multiple sub-circuits, the number of which is a target number, which is the sum of the number of the second chip terminals and the number of extended second chip terminals. Each sub-circuit includes: a third resistor, a sub-temperature detection sub-circuit, and a sub-button. The sub-temperature detection sub-circuit includes a fourth resistor and a sub-thermistor connected in series. The input terminal of the sub-temperature detection sub-circuit is connected to an external power supply, and the output terminal is connected to ground. The input terminal of the third resistor is connected to an extended second chip terminal or to the second chip terminal, and the output terminal of the third resistor is connected between the fourth resistor and the sub-thermistor. The sub-button is connected in parallel across the sub-thermistor.

[0019] Based on the above technical means, the secondary circuit is associated with the extended second chip terminal or the second chip terminal, and the extended second chip terminal and the second chip terminal are reused to realize additional temperature and button detection functions without the need to add a new independent chip IO port, thereby further expanding the detection function, improving the circuit integration and reducing hardware costs.

[0020] In one alternative implementation, when button detection and temperature detection are performed on any set of sub-circuits, the corresponding extended second chip terminal is in an input state.

[0021] Based on the above technical means, the input state of the extended second chip is clearly defined during the secondary circuit detection, ensuring that the voltage signal of the secondary circuit can be accurately collected, thereby accurately judging the button state and ambient temperature, and ensuring the reliability of the secondary circuit detection function.

[0022] In one optional implementation, when the number of available input / output ports of the chip is N and N is an odd number, the total number of the first chip terminal and the extended first chip terminal is N / 2 + 0.5, and the total number of the second chip terminal and the extended second chip terminal is N / 2 - 0.5; when the number of available input / output ports of the chip is N and N is an even number, the total number of the first chip terminal and the extended first chip terminal is N / 2, and the total number of the second chip terminal and the extended second chip terminal is N / 2.

[0023] Based on the above technical means, the number of the two types of chip terminals is reasonably allocated according to the parity of the total number of chip I / O ports (N), maximizing the utilization of existing I / O port resources. Under different I / O port quantities, the optimal matching between functions and I / O ports can be achieved, improving circuit adaptability.

[0024] Secondly, this utility model provides an electrical device, which includes: a function multiplexing circuit as provided in the first aspect or any corresponding embodiment. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the LED display circuit structure in related technologies;

[0027] Figure 2 This is a schematic diagram of the AD detection circuit structure in related technologies;

[0028] Figure 3 This is a schematic diagram of the key detection circuit structure in related technologies;

[0029] Figure 4 This is a schematic diagram of a functional multiplexing circuit according to an embodiment of the present utility model;

[0030] Figure 5 This is another structural schematic diagram of a functional multiplexing circuit according to an embodiment of the present utility model;

[0031] Figure 6 This is another structural schematic diagram of a functional multiplexing circuit according to an embodiment of the present utility model;

[0032] Figure 7 This is another structural schematic diagram of a functional multiplexing circuit according to an embodiment of the present utility model;

[0033] Figure 8 This is a control timing diagram of a functional multiplexing circuit according to an embodiment of the present utility model;

[0034] Figure 9 This is a structural schematic diagram of an electrical device according to an embodiment of the present utility model.

[0035] Figure reference numerals: LED light - L1, First current limiting resistor - R1, First input / output interface - IO1, Target thermistor - NTC1, Voltage divider resistor - R2, Second current limiting resistor - R3, Second input / output interface - IO2, Target button - KEY1, Pull-down resistor - R4, Third input / output interface - IO3, Main circuit - S1, Temperature detection sub-circuit - S2, Button - KEY2, Main LED light - L2, Second resistor - R6, External power supply - VDD, Ground - GND, First resistor - R5, Thermistor - NTC2, First chip terminal - COM1, Second chip terminal - SEG1, First extended main circuit - S3, Second extended main circuit - S4, First expansion first chip terminal - COM2, Second expansion first chip terminal - COM3, First expansion main LED - L3, Second expansion main LED - L4, First auxiliary LED - L5, Second auxiliary LED - L6, Third auxiliary LED - L7, Fourth auxiliary LED - L8, Fifth auxiliary LED - L9, Sixth auxiliary LED - L10, First expansion second chip terminal - SEG2, Second expansion second chip terminal - SEG3, First auxiliary circuit - S5, Second auxiliary circuit - S6, Third auxiliary circuit - S7, Third resistor - R7, Fourth resistor - R8, Auxiliary thermistor NTC3, Auxiliary button KEY3, Function multiplexing circuit 901. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0037] Traditional technologies for small household appliances such as fans, electric heaters, and rice cookers require functions such as buttons, displays, and AD detection of ambient temperature. These typically use dedicated chip I / O ports for LED display, button detection, and AD detection, which usually requires a large number of chip I / O ports, consuming more chip resources and resulting in higher costs.

[0038] For example, Figure 1 These are two forms of LED display circuit schematics in related technologies, with Figure 1 (a) For example, the anode of LED L1 is connected to the positive terminal of the power supply, the cathode is connected to the first current limiting resistor R1, and then connected to the first input / output interface IO1 of the chip. When LED L1 needs to be lit, the first input / output interface IO1 of the chip outputs a low level, and when LED L1 does not need to be lit, it outputs a high level. Figure 2These are two forms of AD detection circuit schematics in related technologies, with Figure 2 (a) For example, the positive terminal of the power supply is connected to the thermistor NTC1 (the resistance value varies depending on the ambient temperature) and the voltage divider resistor R2 to ground. The second current limiting resistor R3 limits the current. The second input / output interface IO2 of the chip detects the voltage value after the target thermistor NTC1 and the voltage divider resistor R2 to obtain the AD detection result. The ambient temperature can be calculated based on the different detected voltage values. Figure 3 Two forms of key detection circuit schematics for related technologies are presented, with Figure 3 (a) For example, the power supply is connected to the target button KEY1, and the pull-down resistor R4 is connected to ground. When the button is pressed, the third input / output interface IO3 of the chip detects a high level, and when the button is not pressed, the third input / output interface IO3 of the chip detects a low level.

[0039] To address the above problems, according to an embodiment of this utility model, a functional multiplexing circuit is provided, such as... Figure 4 As shown, the circuit includes a main circuit S1; the main circuit S1 includes a temperature detection sub-circuit S2, a button KEY2, and a main LED L2. The temperature detection sub-circuit S2 includes a first resistor R5 and a thermistor NTC2 connected in series. The input terminal of the temperature detection sub-circuit S2 is connected to the external power supply VDD. The output terminal of the temperature detection sub-circuit S2 is connected to the ground GND. The button KEY2 is connected in parallel across the thermistor NTC2. The input terminal of the temperature detection sub-circuit S2 is also connected to the first chip terminal COM1, which is one input / output port of the chip. The positive terminal of the main LED L2 is connected to the input terminal of the temperature detection sub-circuit S2, and the negative terminal of the main LED L2 is connected to the second chip terminal SEG1, which is another input / output port of the chip.

[0040] Specifically, the main circuit function multiplexing circuit provided in this embodiment of the utility model is mainly composed of a main circuit S1 alone or in an extended combination. The main circuit S1 includes a temperature detection sub-circuit S2, a button KEY2, and a main LED light L2.

[0041] The temperature detection sub-circuit S2 includes a first resistor R5 and a thermistor NTC2 connected in series. The first resistor R5 is used for voltage division and current limiting, while the thermistor NTC2 is used to detect the external ambient temperature. The input terminal of the temperature detection sub-circuit S2 is connected to the external power supply VDD, and the output terminal is grounded to GND. Figure 4For example, the input terminal of the first resistor R5 is connected to the external power supply VDD, and the output terminal of the thermistor NTC2 is connected to ground GND. The button is connected in parallel across the thermistor NTC2. The input terminal of the temperature detection sub-circuit S2 is also connected to the first chip terminal COM1. The positive terminal of the main LED L2 is connected to the input terminal of the temperature detection sub-circuit S2, and the negative terminal is connected to the second chip terminal SEG1. The first chip terminal COM1 and the second chip terminal SEG1 are two different chip input / output ports. The first chip terminal COM1 and the second chip terminal SEG1 can be located on the same chip or on different chips. In this embodiment of the invention, the specific model of the chip is not specifically limited, as long as it can achieve the functions of input, output high level, and output low level.

[0042] Based on the main circuit S1 structure described above, when performing button detection and temperature detection, the first chip terminal COM1 is set to input state to acquire the voltage signal of the temperature detection sub-circuit S2, and the second chip terminal SEG1 outputs a high level. At this time, the main LED L2 has no current loop and is in an off state, avoiding interference from the main LED L2 lighting on the signal acquisition of the first chip terminal COM1. If button KEY2 is pressed, the thermistor NTC2 is short-circuited, and the voltage acquired by the first chip terminal COM1 is close to zero; if button KEY2 is not pressed, the resistance of the thermistor NTC2 changes with temperature, and the voltage acquired by the first chip terminal COM1 also changes accordingly, thereby realizing temperature and button detection.

[0043] For example: the positive terminal of the power supply is connected to ground via the first resistor R5 (the resistance is usually 1KΩ) and the thermistor NTC2 (the detection temperature range is usually 0-40℃, the resistance is usually 325KΩ at 0℃, 100KΩ at 25℃, and 53KΩ at 40℃). The button KEY2 is connected in parallel with the thermistor NTC2. When the first chip terminal COM1 is the input port, AD detection is performed to detect the voltage at this point. The power supply voltage is usually 5V. When button KEY2 is pressed, the voltage at the first chip terminal COM1 is approximately 0.05V (approximately 5V * 1KΩ / (100KΩ + 1KΩ)). When button KEY2 is not pressed and the temperature is 0℃, the voltage at the first chip terminal COM1 is approximately 3.83V (approximately 5V * (325KΩ + 1KΩ) / (325KΩ + 1KΩ + 100KΩ)). When button KEY2 is not pressed and the temperature is 25℃, the voltage at the first chip terminal COM1 is approximately 2.51V (approximately 5V * (100KΩ + 1KΩ) / (100KΩ + 1KΩ + 100KΩ)). When button KEY2 is not pressed and the temperature is 40℃, the voltage at the first chip terminal COM1 is approximately 1.75V (approximately 5V * (53KΩ + 1KΩ) / (100KΩ + 1KΩ + 53KΩ)). The voltage at the first chip terminal COM1 can be used to determine whether button KEY2 is pressed or to detect the ambient temperature.

[0044] In addition, when the main LED L2 is detected, the first chip terminal COM1 outputs a high level to prevent the positive current of the power supply from flowing into the first chip terminal COM1 and short-circuiting the main LED L2. The second chip terminal SEG1 outputs a low level, and the positive power supply and the second chip terminal SEG1 form a current path, so the main LED L2 lights up, completing the detection of the main LED L2.

[0045] Based on the above technical means, by associating the temperature detection sub-circuit S2, the button KEY2 and the main LED L2, three types of functions can be implemented by reusing two chip I / O ports. There is no need to allocate I / O ports separately for each function, which greatly reduces the chip I / O port occupation, reduces chip resource consumption and hardware costs, and simplifies the circuit structure.

[0046] In some alternative implementations, such as Figure 4 As shown, the main circuit also includes a second resistor R6, which is connected between the external power supply VDD and the input terminal of the temperature detection sub-circuit S2.

[0047] Specifically, in this embodiment of the invention, by adding a second resistor R6, the current is limited, which can limit the amount of current input from the external power supply to the temperature detection sub-circuit S2, prevent excessive current from damaging components such as the thermistor NTC2, extend the service life of the circuit, stabilize the circuit voltage, and improve the temperature detection accuracy.

[0048] In one optional implementation, it further includes multiple extended main circuits, which have the same structure as the main circuit S1. The input terminal of the temperature detection sub-circuit in each extended main circuit is connected to an extended first chip terminal, and the negative terminal of the main LED in each extended main circuit is connected to the second chip terminal SEG1.

[0049] Specifically, this embodiment of the invention also enhances the multiplexing capability of the chip's I / O ports by deploying multiple extended main circuits, for example... Figure 5 The first extended main circuit S3 and the second extended main circuit S4 are shown. The structures of both the first extended main circuit S3 and the second extended main circuit S4 are identical to those of the main circuit S1. Depending on the number of extended main circuits, an additional number of extended first chip terminals are required. For example, the input terminal of the temperature detection sub-circuit of the first extended main circuit S3 is connected to the first extended first chip terminal COM2; the input terminal of the temperature detection sub-circuit of the second extended main circuit S4 is connected to the second extended first chip terminal COM3. Furthermore, the negative terminals of the first extended main LED L3 in the first extended main circuit S3 and the second extended main LED L4 in the second extended main circuit S4 are both connected to the second chip terminal SEG1.

[0050] by Figure 5For example, when the main circuit S1 performs button detection and temperature detection, the first chip terminal COM1 is in the input state, and the second chip terminal SEG1 outputs a high level; if the first extended main circuit S3 performs button detection and temperature detection, then the first extended chip terminal COM2 is in the input state, and the second chip terminal SEG1 outputs a high level; when the second extended main circuit S4 performs button detection and temperature detection, the second extended chip terminal COM3 is in the input state, and the second chip terminal SEG1 outputs a high level. The control principle is the same as described above. Figure 4 The control principle is the same for the main circuit S1 shown, and will not be repeated here.

[0051] When the main circuit S1 detects the main LED L2, the first chip terminal COM1 outputs a high level, and the second chip terminal SEG1 outputs a low level. Simultaneously, the first extended first chip terminal COM2 and the second extended first chip terminal COM3 also need to output low levels, ensuring that only the main LED L2 participating in the test lights up, while other LEDs remain off due to short circuits. When the first extended main circuit S3 detects the first extended main LED L3, the first extended first chip terminal COM2 outputs a high level, and the second chip terminal SEG1 outputs a low level. Similarly, the first chip terminal COM1 and the second extended first chip terminal COM3 also need to output low levels. When the second extended main circuit S4 detects the second extended main LED L4, the second extended first chip terminal COM3 outputs a high level, and the second chip terminal SEG1 outputs a low level. Similarly, the first chip terminal COM1 and the first extended first chip terminal COM2 also need to output low levels. Through the above circuit connection structure and I / O port states, based on the reuse of the second chip terminal SEG1, and utilizing different extended first chip terminals, the button, temperature detection, and main LED detection functions of multiple extended main circuits are further expanded. Furthermore, the chip states are standardized during the testing of the main circuit and extended main circuits to avoid signal interference caused by multiple circuits operating simultaneously. This ensures that each circuit completes testing independently, in a time-sharing manner, and accurately, performing button testing, temperature testing, and main LED testing on only one main circuit at a time. During main LED testing, the corresponding first chip terminal or the corresponding extended first chip terminal outputs a high level, while the other first chip terminals and / or other extended first chip terminals that are not involved in the testing output a low level. The second chip terminal outputs a low level, enabling only the LEDs involved in the test to light up while the others remain off. This allows for flexible control of the testing targets and improves the flexibility of circuit use.

[0052] In some optional implementations, the main circuit S1 and / or the extended main circuit further include multiple secondary LEDs; wherein the positive terminal of each secondary LED is connected to the input terminal of the temperature detection sub-circuit in the corresponding main circuit S1, or to the input terminal of the temperature detection sub-circuit in the corresponding extended main circuit; the negative terminal of each secondary LED is connected to an extended second chip terminal; wherein the extended second chip terminals connected to multiple secondary LEDs located in the same main circuit S1 or the same extended main circuit are different; at the same time, each extended second chip terminal is used for sharing a connection between a secondary LED in the main circuit and a secondary LED in a different extended main circuit.

[0053] Specifically, the main circuit S1 and / or each extended main circuit also includes multiple auxiliary LEDs. For example... Figure 6 As shown, the main circuit S1 may include a first LED L5 and a second LED L6. Since both the first LED L5 and the second LED L6 belong to the main circuit S1, the positive terminal of the first LED L5 is connected to the input terminal of the temperature detection sub-circuit S2 in the main circuit S1, and the negative terminal is connected to the first extended second chip terminal SEG2; the positive terminal of the second LED L6 is also connected to the input terminal of the temperature detection sub-circuit S2 in the main circuit S1, but the negative terminal needs to be connected to the second extended second chip terminal SEG3.

[0054] The expansion methods for other main circuits are similar to those for the main circuit, for example... Figure 6 As shown, the first extended main circuit S3 and the second extended main circuit S4 respectively include a third LED lamp L7, a fourth LED lamp L8, a fifth LED lamp L9 and a sixth LED lamp L10.

[0055] With the above structure, the first extended second chip terminal SEG2 is shared by the first auxiliary LED L5 of the main circuit S1, the third auxiliary LED L7 of the first extended main circuit S3, and the fifth auxiliary LED L9 of the second extended main circuit S4. The second extended second chip terminal SEG3 is shared by the second auxiliary LED L6 of the main circuit S1, the fourth auxiliary LED L8 of the first extended main circuit, and the sixth auxiliary LED L10 of the second extended main circuit. When the first LED L5 in the main circuit S1 needs to be lit, the first chip terminal COM1 in the main circuit S1 outputs a high level, and the first extended second chip terminal SEG2 outputs a low level. At the same time, the corresponding first extended first chip terminal COM2 and second extended first chip terminal COM3 in the first extended main circuit S3 and the second extended main circuit S4 need to be set to output a low level so that the third LED L7, the fourth LED L8, the fifth LED L9, and the sixth LED L10 are not lit. Similarly, when controlling the other LEDs to be lit, the temperature detection sub-circuit input terminal of the corresponding main circuit or extended main circuit outputs a high level, and the circuits of other LEDs sharing the same extended second chip terminal do not meet the lighting conditions, so the corresponding extended first chip terminal outputs a low level, thereby realizing the multiplexing of the extended second chip terminal function.

[0056] Based on the aforementioned technical methods, multiple secondary LEDs are added to the main circuit or each extended main circuit for testing. Furthermore, one secondary LED in each main circuit or extended main circuit shares a single extended second chip terminal, eliminating the need to allocate a separate chip I / O port for each secondary LED. This increases the number of LEDs displayed while reducing I / O port usage, further optimizing I / O port resource utilization and meeting multi-display requirements. Additionally, during testing, the output state of the chip I / O ports is clearly defined when secondary LEDs are being tested, preventing signals from chips not participating in the test from affecting the results. This ensures accurate detection of the on / off state of each secondary LED and guarantees the stable implementation of the multi-LED display function.

[0057] In one optional embodiment, the functional multiplexing circuit provided by this utility model further includes multiple sub-circuits. The number of sub-circuits is a target number, which is the sum of the number of second chip terminals and the number of extended second chip terminals. The sub-circuit includes: a third resistor, a sub-temperature detection sub-circuit, and a sub-button. The sub-temperature detection sub-circuit includes a fourth resistor and a sub-thermistor connected in series. The input terminal of the sub-temperature detection sub-circuit is connected to an external power supply, and the output terminal of the sub-temperature detection sub-circuit is connected to ground. The input terminal of the third resistor is connected to an extended second chip terminal or to the second chip terminal, and the output terminal of the third resistor is connected between the fourth resistor and the sub-thermistor. The sub-button is connected in parallel across the sub-thermistor.

[0058] Specifically, such as Figure 7As shown, this embodiment of the invention also deploys a set of sub-circuits on the second chip terminal SEG1 and each extended second chip terminal. Assuming two extended second chip terminals are provided, namely the first extended second chip terminal SEG2 and the second extended second chip terminal SEG3, this embodiment of the invention is equipped with three sets of sub-circuits: the first sub-circuit S5, the second sub-circuit S6, and the third sub-circuit S7. Taking the first sub-circuit S5 as an example, the input terminal of the third resistor R7 is connected to the second chip terminal SEG1, and the output terminal of the third resistor R7 is connected to the intermediate connection point of the sub-temperature detection sub-circuit composed of the fourth resistor R8 and the sub-thermistor NTC3 connected in series. The third resistor R7 serves as a current limiter. The sub-button KEY3 is connected in parallel across the sub-thermistor NTC3. The input terminal of the sub-temperature detection sub-circuit is connected to the external power supply VDD, and the output terminal is grounded to GND. The second sub-circuit S6 and the third sub-circuit S7 are similar. When the first secondary circuit S5 is used for button and temperature detection, the second chip terminal SEG1 is configured as an input state to collect the voltage signal of the secondary temperature detection sub-circuit. If the secondary button KEY3 is pressed, the secondary thermistor NTC3 is short-circuited, and the voltage collected by the second chip terminal SEG1 is close to 0V. If the secondary button KEY3 is not pressed, the resistance of the secondary thermistor NTC3 changes with the temperature, and the voltage collected by the second chip terminal SEG1 changes accordingly. This realizes the button and temperature detection of the secondary circuit, and reuses the second chip terminal SEG1 without the need for an additional independent chip I / O port.

[0059] Based on the above technical means, the secondary circuit is associated with the extended second chip terminal and the second chip terminal. The extended second chip terminal and the second chip terminal are reused to realize additional temperature and button detection functions without the need to add a new independent IO port, thereby further expanding the detection function, improving the circuit integration and reducing hardware costs.

[0060] In one optional implementation, when the number of available input / output ports of the chip is N and N is an odd number, the total number of the first chip terminal COM1 and each extended first chip terminal is N / 2 + 0.5, and the total number of the second chip terminal SEG1 and each extended second chip terminal is N / 2 - 0.5; when the number of available input / output ports of the chip is N and N is an even number, the total number of the first chip terminal COM1 and the extended first chip terminal is N / 2, and the total number of the second chip terminal SEG1 and the extended second chip terminal is N / 2.

[0061] Specifically, in this embodiment of the invention, the number of the first chip terminal, the extended first chip terminal, the second chip terminal, and the extended second chip terminal are configured according to the available chip I / O ports, and are specifically based on the following principles:

[0062] When the number of available input / output ports of the chip is N and N is an odd number, the total number of the first chip terminal COM1 and the extended first chip terminal is N / 2+0.5, and the total number of the second chip terminal SEG1 and the extended second chip terminal is N / 2-0.5.

[0063] For example, when the number of available input / output ports N of the chip is an even number (6), the total number of the first chip port COM1 and the extended first chip port is 6 / 2 = 3, and the total number of the second chip port SEG1 and the extended second chip port is also 6 / 2 = 3. When N is an odd number, such as N = 5, the total number of the first chip port COM1 and the extended first chip port is 5 / 2 + 0.5 = 3, and the total number of the second chip port SEG1 and the extended second chip port is 5 / 2 - 0.5 = 2. This allocation method allows for flexible and full utilization of port resources based on the odd or even number of chip input / output ports, adapting to different circuit function expansion requirements. Thus, with N chip I / O ports, if N is odd, a maximum of (N-1)*(N+1) / 4 LEDs can be controlled; if N is even, a maximum of n*n / 4 LEDs can be controlled, along with the detection of N buttons and N thermistors. For example, when N=6, a 2x4 matrix can be formed to control 8 LEDs, or a 3x3 matrix can be formed to control 9 LEDs. Therefore, when the total number of the first chip terminal COM1 and the extended first chip terminal is 3, and the total number of the second chip terminal SEG1 and the extended second chip terminal is also 3, it is possible to configure and control 9 LEDs, which is the maximum number of LEDs that can be controlled.

[0064] Based on the above technical means, the number of the two types of chip terminals is reasonably allocated according to the parity of the total number of chip I / O ports, so as to maximize the use of existing I / O port resources. Under different I / O port quantities, the optimal matching between functions and I / O ports can be achieved, thereby improving circuit adaptability.

[0065] In a specific application embodiment, as described above Figure 7 Taking the functional multiplexing circuit shown as an example, this utility model embodiment provides, as follows: Figure 8 The nine configuration stages shown are for controlling different LED lights, buttons, and temperature sensors respectively. This embodiment only uses... Figure 8 For example, in practical applications, the order of stages 1 to 9 can be adjusted arbitrarily according to the user's needs.

[0066] Figure 8 The dashed line indicates that the corresponding chip I / O port is in input mode, the solid line indicates that the I / O port is in output mode, the solid line at the bottom indicates low level output, the solid line at the top indicates high level output, and the unlined area indicates that the output state is uncertain, and it can output either high level or low level, depending on the actual needs.

[0067] In stage 1, the first chip terminal COM1 outputs a high level, while the first extended first chip terminal COM2 and the second extended first chip terminal COM3 output a low level. If any LED needs to be lit, the corresponding second chip terminal SEG1, the first extended second chip terminal SEG2, or the second extended second chip terminal SEG3 outputs a low level; conversely, if no LED needs to be lit, the corresponding second chip terminal SEG1, the first extended second chip terminal SEG2, or the second extended second chip terminal SEG3 outputs a high level. During this stage, the main LED L2, the first auxiliary LED L5, and the second auxiliary LED L6 can be controlled to turn on or off; the remaining LEDs will not be lit. Because the chip's I / O ports only have two states—high and low—during this stage, and according to the circuit design of this invention, whether a button is pressed or not will not affect the LED display.

[0068] In Phase 2, the first chip terminal COM1, the first extended first chip terminal COM2, and the second extended first chip terminal COM3 simultaneously output a low level. The second chip terminal SEG1, the first extended second chip terminal SEG2, and the second extended second chip terminal SEG3 are simultaneously set as input ports for AD detection to detect whether a button is pressed or to detect the ambient temperature. During this time, the LEDs will not be lit. If the first chip terminal COM1, the first extended first chip terminal COM2, and the second extended first chip terminal COM3 do not output a low level, the LEDs will light up uncontrollably, as current flows through the first auxiliary circuit S5 to ground, forming a path.

[0069] In Phase 3, the second chip terminal SEG1, the first extended second chip terminal SEG2, and the second extended second chip terminal SEG3 simultaneously output high levels. The first chip terminal COM1, the first extended first chip terminal COM2, and the second extended first chip terminal COM3 are simultaneously set as input ports for AD detection to detect whether a button is pressed or to detect the ambient temperature. During this time, none of the LEDs will be lit. If the second chip terminal SEG1, the first extended second chip terminal SEG2, and the second extended second chip terminal SEG3 do not output high levels, it will affect the input detection of the first chip terminal COM1, the first extended first chip terminal COM2, and the second extended first chip terminal COM3. For example, if a path is formed from the first auxiliary circuit S5 to ground, it will affect the AD detection value of COM1.

[0070] In stage 4, similar to stage 1, the first extended first chip terminal COM2 outputs a high level, and the first chip terminal COM1 and the second extended first chip terminal COM3 output a low level. If any LED needs to be lit, the corresponding second chip terminal SEG1, the first extended second chip terminal SEG2, or the second extended second chip terminal SEG3 outputs a low level. If the LED does not need to be lit, the corresponding second chip terminal SEG1, the first extended second chip terminal SEG2, or the second extended second chip terminal SEG3 outputs a high level.

[0071] Phase 5 is the same as Phase 2.

[0072] Phase 6 is consistent with Phase 3.

[0073] Phase 7 is similar to Phase 1 and Phase 4.

[0074] Phase 8 is consistent with Phase 5 and Phase 2.

[0075] Phase 9 is consistent with Phase 6 and Phase 3.

[0076] Performing AD detection on the first chip terminal COM1, the first extended first chip terminal COM2, the second extended first chip terminal COM3, the second chip terminal SEG1, the first extended second chip terminal SEG2, and the second extended second chip terminal SEG3 in time periods can avoid mutual interference between circuits. Stages 1 to 9 constitute one cycle, and a new cycle begins after stage 9. In this embodiment of the invention, the cycle frequency is required to be much higher than the persistence of vision of the human eye, typically 2kHz, to achieve the effect that the human eye perceives the LED as constantly lit. For example, D1 may only actually light up in stage 1, but because the cycle frequency is high enough, according to the persistence of vision of the human eye, if D1 lights up in stage 1 of each cycle, the human eye will perceive D1 as constantly lit. The duration of stages 1, 4, and 7 within this cycle can be slightly longer to achieve a better display effect. Stages 2, 3, 5, 6, 8, and 9 within this cycle can be reduced as needed, such as eliminating stages 5, 6, 8, and 9. Retaining all samples results in a higher sampling rate, which is beneficial for more accurate detection of AD values ​​or whether a button has been pressed. Removing some samples results in a lower sampling rate.

[0077] This utility model also provides an electrical device, such as Figure 9 As shown, the electrical device includes a function multiplexing circuit 901 provided in another embodiment of the present invention. For details regarding the function multiplexing circuit 901, please refer to the relevant description of another embodiment of the present invention, which will not be repeated here.

[0078] For example, the electrical device can be a fan, electric heater, humidifier, or other product that requires both LED display and temperature detection, as well as buttons.

[0079] The electrical equipment provided in this embodiment of the utility model uses a function multiplexing circuit to control an LED light, a button, and a temperature sensor using two level signals. Each level signal can independently control an LED light to turn on or off. By associating the temperature detection sub-circuit, the button, and the LED light, three types of functions are achieved by multiplexing two chip I / O ports. This eliminates the need to allocate I / O ports separately for each function, significantly reducing the number of chip I / O ports occupied, lowering chip resource consumption and hardware costs, simplifying the circuit structure, reducing the requirements for selecting peripheral control chip I / O port resources, lowering chip selection costs, and thus reducing the overall hardware cost of the electrical equipment.

[0080] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A function multiplexing circuit, characterized by comprising: Includes a main circuit; the main circuit includes a temperature detection sub-circuit, a button and a main LED, the temperature detection sub-circuit including a first resistor and a thermistor connected in series; The input terminal of the temperature detection sub-circuit is connected to an external power supply; The output terminal of the temperature detection sub-circuit is connected to the ground wire; The button is connected in parallel across the thermistor; The input terminal of the temperature detection sub-circuit is also connected to the first chip terminal, which is an input / output port of the chip. The positive terminal of the main LED is connected to the input terminal of the temperature detection sub-circuit, and the negative terminal of the main LED is connected to the second chip terminal, which is another input / output port of the chip.

2. The functional multiplexing circuit of claim 1, wherein, When performing button detection and temperature detection, the first chip terminal is in input state, and the second chip terminal outputs a high level; when performing main LED light detection, the first chip terminal outputs a high level, and the second chip terminal outputs a low level.

3. The functional multiplexing circuit of claim 2, wherein, The main circuit also includes a second resistor connected between the external power supply and the input terminal of the temperature detection sub-circuit.

4. The functional multiplexing circuit of claim 3, wherein, It also includes multiple extended main circuits, which have the same structure as the main circuit. In each extended main circuit, the input terminal of the temperature detection sub-circuit is connected to an extended first chip terminal, and the negative terminal of the main LED in each extended main circuit is connected to the second chip terminal.

5. The functional multiplexing circuit of claim 4, wherein, When either the main circuit or the extended main circuit performs key detection and temperature detection, the corresponding first chip terminal or the corresponding extended first chip terminal is in the input state, and the second chip terminal outputs a high level. When either the main circuit or the extended main circuit performs main LED detection, the corresponding first chip terminal or the corresponding extended first chip terminal outputs a high level, the remaining first chip terminals and / or the remaining extended first chip terminals that do not participate in the detection output a low level, and the second chip terminal outputs a low level.

6. The functional multiplexing circuit of claim 5, wherein, The main circuit and / or the extended main circuit also include multiple secondary LEDs; wherein the positive terminal of each secondary LED is connected to the input terminal of the temperature detection sub-circuit in the corresponding main circuit, or to the input terminal of the temperature detection sub-circuit in the corresponding extended main circuit; the negative terminal of each secondary LED is connected to an extended second chip terminal; wherein the extended second chip terminals connected to multiple secondary LEDs located in the same main circuit or the same extended main circuit are different; at the same time, each extended second chip terminal is used for a shared connection between a secondary LED in the main circuit and a secondary LED in a different extended main circuit.

7. The functional multiplexing circuit of claim 6, wherein, When any one of the secondary LEDs is being tested, the corresponding first chip terminal or the corresponding extended first chip terminal outputs a high level, the other first chip terminals and / or the other extended first chip terminals that are not involved in the test output a low level, and the corresponding extended second chip terminal that is involved in the test outputs a low level.

8. The functional multiplexing circuit of claim 6, wherein, It also includes multiple sub-circuits, the number of which is a target number, which is the sum of the number of the second chip terminal and the number of the extended second chip terminal. The sub-circuit includes: a third resistor, a sub-temperature detection sub-circuit, and a sub-button. The secondary temperature detection sub-circuit includes a fourth resistor and a secondary thermistor connected in series. The input terminal of the secondary temperature detection sub-circuit is connected to an external power supply, and the output terminal of the secondary temperature detection sub-circuit is connected to ground. The input terminal of the third resistor is connected to an extended second chip terminal or to the second chip terminal, and the output terminal of the third resistor is connected between the fourth resistor and the auxiliary thermistor. The secondary button is connected in parallel across the secondary thermistor.

9. The functional multiplexing circuit of claim 8, wherein, When performing button detection and temperature detection on any set of secondary circuits, the corresponding extended second chip terminal is in the input state.

10. The functional multiplexing circuit according to claim 8, characterized in that, When the number of available input / output ports of the chip is N and N is an odd number, the total number of the first chip terminal and the extended first chip terminal is N / 2 + 0.5, and the total number of the second chip terminal and the extended second chip terminal is N / 2 - 0.

5. When the number of available input / output ports of the chip is N and N is an even number, the total number of the first chip terminal and the extended first chip terminal is N / 2, and the total number of the second chip terminal and the extended second chip terminal is N / 2.

11. An electrical appliance, characterized in that, The electrical device includes: a function multiplexing circuit as described in any one of claims 1-10.

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