Circuit for saving computer board IO ports and microwave oven

Abstract

The utility model provides a circuit for saving computer board IO port and a microwave oven, the circuit comprises a one-chip microcomputer module, a filtering module, a matrix button module, a column multiplexing module and a display module circuit, the one-chip microcomputer module is respectively electrically connected with the matrix button module and the column multiplexing module through the filtering module; the single-chip microcomputer module is electrically connected with the display module circuit. According to the circuit for saving the IO ports of the computer board and the microwave oven, the circuit structure of the control chip in the computer board for controlling different loads can be simplified, the requirements of the loads on the IO ports on the control chip are reduced, the development cost of the computer board is further reduced, and the operation stability and safety of the computer board in the microwave oven are improved.

Description

Technical Field

[0001] The utility model relates to the field of microwave ovens, and more specifically, to a circuit for saving the IO ports of a computer board and a microwave oven. Background Art

[0002] Since the control chip of the microwave oven computer board needs to control loads such as a display component, buttons, and relays, the computer board has a relatively high demand for the number of IO ports of the chip. Among them, when the existing microwave oven computer board controls buttons, it generally uses N rows multiplied by N columns to form a matrix to control mechanical or membrane switch buttons, so the number of IO requirements is 2N. For example, controlling 25 buttons requires at least 10 IO ports, where 5 IO ports are used for rows and 5 IO ports are used for columns, increasing the chip IO resources. In addition, the indicator light display or digital tube display in the display component generally also requires separate use of other IO ports, increasing the demand for the chip IO ports, which easily causes insufficient chip IO resources. Therefore, other chips with more IO ports are used, increasing the development cost. Therefore, it is of great significance to study how to save the IO ports of the computer board and reduce the development cost of the computer board in the microwave oven.

[0003] In Patent CN202435659U, a lamp intelligent controller is mentioned, which includes a box body, a circuit board, and an external lamp device. The box body includes a button group and a display screen; the circuit board is arranged inside the box body; the circuit board includes a single-chip microcomputer working circuit, an ambient light detection circuit, a human presence detection circuit, a system clock circuit, a lamp setting circuit, a display circuit, and a lamp driving circuit; the single-chip microcomputer working circuit is respectively connected to the ambient light detection circuit, the human presence detection circuit, the system clock circuit, the lamp setting circuit, the display circuit, and the lamp driving circuit; the ambient light detection circuit is connected to the single-chip microcomputer working circuit; the human presence detection circuit is connected to the single-chip microcomputer working circuit; the system clock circuit is connected to the single-chip microcomputer working circuit; the lamp setting circuit is respectively connected to the button group and the single-chip microcomputer working circuit; the display circuit is respectively connected to the display screen and the single-chip microcomputer working circuit; the lamp driving circuit is respectively electrically connected to the single-chip microcomputer working circuit and the external lamp device, receives the control signal output by the single-chip microcomputer working circuit, and controls the turning on and off of the external lamp device. Through the setting of this controller, the on-off control of the lamp can be achieved. However, since this controller requires fewer buttons and does not enable the IO port setting in the row-column mode, although the required number of IO ports seems small, as the number of buttons increases, based on the current control circuit structure, there is still a problem of excessive IO port demand, which further increases the R & D cost. Summary of the Utility Model

[0004] In view of this, the purpose of the present utility model is to propose a circuit and a microwave oven for saving the IO ports of a computer board, so as to solve the problem in the prior art that there are many loads controlled by the computer board in the microwave oven, resulting in an increased demand for the number of IO ports on the control chip, and further due to the shortage of IO port resources of the control chip, the development cost of the computer board is relatively high; thereby achieving the ability to simplify the circuit structure for the control chip in the computer board to control different loads, and reducing the demand for IO ports on the control chip by the loads without reducing the number of loads driven by the control chip in the computer board, thereby reducing the development cost of the computer board and improving the stability and safety of the operation of the computer board in the microwave oven.

[0005] To achieve the above object, the technical solution of the present utility model is realized as follows:

[0006] A circuit and a microwave oven for saving the IO ports of a computer board according to the present utility model, the circuit for saving the IO ports of a computer board includes a single-chip microcomputer module, a filtering module, a matrix key module, a column multiplexing module, and a display module circuit. The single-chip microcomputer module is electrically connected to the matrix key module and the column multiplexing module respectively through the filtering module, and the single-chip microcomputer module is electrically connected to the display module circuit.

[0007] Further, the display module circuit includes an indicator light display circuit or a digital tube display circuit.

[0008] Further, the filtering module is a key input RC filtering module.

[0009] Further, the single-chip microcomputer module includes a control chip, the control chip includes IO ports, and the control chip is electrically connected to the filtering module and the display module circuit respectively through the IO ports.

[0010] Further, n IO ports are provided.

[0011] Further, the n IO ports are respectively denoted as the first IO port IO1, the second IO port IO2,..., the nth IO port IOn. The single-chip microcomputer module is electrically connected to the filtering module and the display module circuit respectively through the first IO port IO1, the second IO port IO2,..., the (n - 1)th IO port IOn - 1, and the single-chip microcomputer module is electrically connected to the display module circuit through the nth IO port IOn.

[0012] Further, the filtering module includes a filtering capacitor C and a filtering resistor R. One end of the filtering capacitor C is electrically connected to one end of the filtering resistor R and the IO port respectively, the other end of the filtering capacitor C is grounded, and the other end of the filtering resistor R is electrically connected to the matrix key module and the column multiplexing module respectively.

[0013] Further, the matrix key module includes m keys, and the m keys are arranged in a matrix form, where m is a positive integer.

[0014] Further, the display module circuit includes a triode Q1, a light-emitting diode LED, and a voltage-dividing resistor r. The base of the triode Q1 is electrically connected to the single-chip microcomputer module through a voltage-dividing resistor r0. The collector of the triode Q1 is connected to VCC or the power supply, and the emitter of the triode Q1 is sequentially connected to the single-chip microcomputer module through the light-emitting diode LED and the voltage-dividing resistor r.

[0015] A microwave oven, which comprises the circuit for saving the IO ports of the computer board as described above, and the circuit is arranged on the computer board in the microwave oven.

[0016] Compared with the prior art, the circuit for saving the IO ports of the computer board and the microwave oven according to the present invention have the following beneficial effects:

[0017] By arranging the circuit in the microwave oven, the circuit structure for the control chip in the computer board to control different loads can be simplified. Without reducing the number of loads driven by the control chip in the computer board, the demand of the loads for the IO ports on the control chip can be reduced, thereby reducing the development cost of the computer board and improving the stability and safety of the operation of the computer board in the microwave oven. Description of the Drawings

[0018] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0019] Figure 1 It is a schematic diagram of the circuit principle.

[0020] Description of the reference numerals in the drawings: 1. Single-chip microcomputer module; 2. Filter module; 3. Matrix key module; 4. Column multiplexing module; 5. Display module circuit. Detailed Embodiments

[0021] Hereinafter, the inventive concepts of the present disclosure will be described using the terms that those skilled in the art would typically use to convey the substance of their work to other artisans in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0022] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0023] Hereinafter, the present invention will be described in detail with reference to the drawings and in conjunction with the embodiments.

[0024] This embodiment is directed to a microwave oven. The same as a conventional microwave oven, the overall structure is composed of a magnetron, a power transformer, and a furnace cavity.

[0025] In the prior art, when the computer board of a microwave oven controls the buttons, it generally uses an N-row by N-column matrix to control mechanical or membrane switch buttons, and then the number of IO requirements is 2N. In addition, the indicator light display or digital tube display in the display component generally also requires separate use of other IO ports, which increases the demand for the chip's IO ports, easily causes insufficient chip IO resources, and thus switches to a chip with a larger number of other IO ports, increasing the development cost.

[0026] To solve the problem in the prior art that the computer board in the microwave oven controls a large number of loads, resulting in an increased demand for the number of IO ports on the control chip, and then due to the shortage of the control chip's IO port resources, the cost of developing the computer board is relatively high; this embodiment proposes a circuit and a microwave oven for saving the IO ports of the computer board. The circuit for saving the IO ports of the computer board includes a single-chip microcomputer module 1, a filtering module 2, a matrix button module 3, a column multiplexing module 4, and a display module circuit 5. The single-chip microcomputer module 1 is electrically connected to the matrix button module 3 and the column multiplexing module 4 through the filtering module 2 respectively, and the single-chip microcomputer module 1 is electrically connected to the display module circuit 5. Under the action of the single-chip microcomputer module 1, it is possible to control the matrix button module 3 through the filtering module 2 and / or the column multiplexing module 4 to achieve switching in multiple situations, and it is also possible to directly control the display module circuit 5 to perform corresponding display operations. In this embodiment, the display module circuit 5 includes an indicator light display circuit or a digital tube display circuit, which is specifically set according to requirements; the filtering module 2 is a button input RC filtering module, which is used to reduce the high-frequency noise or high-frequency interference signals in the circuit, thereby improving the control intensity of the single-chip microcomputer module 1 on each sub-module and improving the stability of the circuit.

[0027] Through the setting of the circuit, it is possible to simplify the circuit structure for the control chip in the computer board to control different loads. Without reducing the number of loads that the control chip in the computer board needs to drive, it is possible to reduce the demand for the IO ports on the control chip by the loads, thereby reducing the development cost of the computer board and improving the stability and safety of the operation of the computer board in the microwave oven.

[0028] The single-chip microcomputer module 1 includes a control chip, the control chip includes IO ports, and the control chip is electrically connected to the filtering module 2 and the display module circuit 5 through the IO ports respectively. n IO ports are set, and the n IO ports are respectively denoted as the first IO port IO1, the second IO port IO2,..., the nth IO port IOn. The single-chip microcomputer module 1 is electrically connected to the filtering module 2 and the display module circuit 5 through the first IO port IO1, the second IO port IO2,..., the (n - 1)th IO port IOn - 1 respectively, and the single-chip microcomputer module 1 is electrically connected to the display module circuit 5 through the nth IO port IOn. Among them, according to the different number of buttons, the value of n will change accordingly, which is specifically set according to requirements.

[0029] Preferably, n = 5. The IO ports include a first IO port IO1, a second IO port IO2, a third IO port IO3, a fourth IO port IO4, and a fifth IO port IO5. The single-chip microcomputer module 1 is electrically connected to the filtering module 2 and the display module circuit 5 through the first IO port IO1, the second IO port IO2, the third IO port IO3, and the fourth IO port IO4 respectively, and the single-chip microcomputer module 1 is electrically connected to the display module circuit 5 through the fifth IO port IO5.

[0030] According to the different numbers of buttons required by different models of microwave ovens, the set number of IO ports can be adjusted accordingly. This can improve the full utilization of IO resources in the circuit, help reduce cost consumption, enhance the flexibility of circuit settings, and make the maintenance and management of the circuit simpler.

[0031] The filtering module 2 includes a filtering capacitor C and a filtering resistor R. One end of the filtering capacitor C is electrically connected to one end of the filtering resistor R and the IO port respectively. The other end of the filtering capacitor C is grounded. The other end of the filtering resistor R is electrically connected to the matrix button module 3 and the column multiplexing module 4 respectively. Both the filtering capacitor C and the filtering resistor R are provided with n - 1. The n - 1 filtering capacitors C are respectively denoted as a first capacitor C1, a second capacitor C2,..., an (n - 1)th capacitor Cn - 1, and the n - 1 filtering resistors are respectively denoted as a first resistor R1, a second resistor R2,..., an (n - 1)th resistor Rn - 1. One ends of the first capacitor C1, the second capacitor C2,..., the (n - 1)th capacitor Cn - 1 are electrically connected to one ends of the corresponding first resistor R1, second resistor R2,..., (n - 1)th resistor Rn - 1 respectively. One ends of the first capacitor C1, the second capacitor C2,..., the (n - 1)th capacitor Cn - 1 are electrically connected to the first IO port IO1, the second IO port IO2,..., the (n - 1)th IO port IOn - 1 respectively. The other ends of the first capacitor C1, the second capacitor C2,..., the (n - 1)th capacitor Cn - 1 are connected in parallel to the ground; the other ends of the first resistor R1, the second resistor R2,..., the (n - 1)th resistor Rn - 1 are electrically connected to the matrix button module 3 and the column multiplexing module 4 respectively.

[0032] Preferably, n = 5, and 4 filtering capacitors C and 4 filtering resistors R are provided. The 4 filtering capacitors C are respectively denoted as the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4, and the 4 filtering resistors R are respectively denoted as the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4. One end of the first capacitor C1 is electrically connected to one end of the first resistor R1 and the first IO port IO1 respectively; one end of the second capacitor C2 is electrically connected to one end of the second resistor R2 and the second IO port IO2 respectively; one end of the third capacitor C3 is electrically connected to one end of the third resistor R3 and the third IO port IO3 respectively; one end of the fourth capacitor C4 is electrically connected to one end of the fourth resistor R4 and the fourth IO port IO4 respectively; the other ends of the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are grounded, and the other ends of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are electrically connected to the matrix key module 3 and the column multiplexing module 4 respectively.

[0033] Through the setting of the filtering module 2, it is beneficial to perform high-frequency filtering on the communication signals of the matrix key module 3 and the column multiplexing module 4 respectively, and it can also facilitate the corresponding filtering process of high-frequency noise, which is beneficial to improving the operation reliability of the circuit, and is also beneficial to enhancing the operation stability of the circuit, improving the control efficiency of the internal control chip of the circuit, and avoiding the phenomenon that the high-frequency signal or noise interference affects the accuracy of the control chip for controlling each load.

[0034] The matrix key module 3 includes m keys, and the m keys are arranged in a matrix form and are connected in parallel in pairs; where m is a positive integer and m = (n - 1). 2 . The m keys are respectively denoted as SW1, SW2,..., SWm. Every n - 1 keys form a row or a column. One end of the keys in each row is electrically connected to the ends of the first resistor R1, the second resistor R2,..., the (n - 1)th resistor Rn - 1 far from the IO port respectively, and the other ends of the keys in each row are electrically connected to the ends of the first resistor R1, the second resistor R2,..., the (n - 1)th resistor Rn - 1 far from the IO port respectively through the column multiplexing module 4. In this embodiment, the type of the key is a membrane switch type key or a mechanical key.

[0035] Preferably, n = 5, and the matrix key module 3 includes 16 keys. The 16 keys are respectively denoted as SW1, SW2, SW3, ..., SW16. Among them, every four keys form a row or a column. After one ends of SW1, SW2, SW3, and SW4 are connected in parallel pairwise, they are electrically connected to the end of the first resistor R1 away from the IO port; after one ends of SW5, SW6, SW7, and SW8 are connected in parallel pairwise, they are electrically connected to the end of the second resistor R2 away from the IO port; after one ends of SW9, SW10, SW11, and SW12 are connected in parallel pairwise, they are electrically connected to the end of the third resistor R3 away from the IO port; after one ends of SW13, SW14, SW15, and SW16 are connected in parallel pairwise, they are electrically connected to the end of the fourth resistor R4 away from the IO port; the other ends of SW1, SW5, SW9, and SW13 are connected in parallel and then electrically connected to the end of the first resistor R1 away from the IO port through the column multiplexing module 4; the other ends of SW2, SW6, SW10, and SW14 are connected in parallel and then electrically connected to the end of the second resistor R2 away from the IO port through the column multiplexing module 4; the other ends of SW3, SW7, SW11, and SW15 are connected in parallel and then electrically connected to the end of the third resistor R3 away from the IO port through the column multiplexing module 4; the other ends of SW4, SW8, SW12, and SW16 are connected in parallel and then electrically connected to the end of the fourth resistor R4 away from the IO port through the column multiplexing module 4.

[0036] Through the n - 1×n - 1 matrix arrangement setting between the keys, it is beneficial to facilitate the use of each key of the microwave oven by implementing the row - column multiplexing method, and it can save the use of IO resources and reduce the cost of computer board development.

[0037] The column multiplexing module 4 includes the first diode D1, the second diode D2, ..., the (n - 1)th diode Dn - 1. The anodes of the first diode D1, the second diode D2, ..., the (n - 1)th diode Dn - 1 are respectively electrically connected to the ends of the first resistor R1, the second resistor R2, ..., the (n - 1)th resistor Rn - 1 away from the IO port, and the cathodes of the first diode D1, the second diode D2, ..., the (n - 1)th diode Dn - 1 are respectively connected to the ends of each column of keys connected in parallel.

[0038] Preferably, n = 5, and the column multiplexing module 4 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anodes of the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 are electrically connected to one ends of a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4 that are far from the IO port, respectively; the cathode of the first diode D1 is electrically connected to one end where SW1, SW5, SW9, and SW13 are connected in parallel; the cathode of the second diode D2 is electrically connected to one end where SW2, SW6, SW10, and SW14 are connected in parallel; the cathode of the third diode D3 is electrically connected to one end where SW3, SW7, SW11, and SW15 are connected in parallel; the cathode of the fourth diode D4 is electrically connected to one end where SW4, SW8, SW12, and SW16 are connected in parallel.

[0039] Through the setting of each diode in the column multiplexing module 4, based on the unidirectional conductivity of the diode, column multiplexing of the keys can be achieved. That is, since the matrix keys are identified by determinant scanning, multiplexing the rows as columns can greatly reduce the chip IO resources, and thus save the IO port.

[0040] The display module circuit 5 includes a triode Q1, a light-emitting diode LED, and a voltage-dividing resistor r. The base of the triode Q1 is electrically connected to the single-chip microcomputer module 1 through a tube voltage-dividing resistor r0; the collector of the triode Q1 is connected to VCC or the power supply, and the emitter of the triode Q1 is sequentially connected to the single-chip microcomputer module 1 through the light-emitting diode LED and the voltage-dividing resistor r. Among them, n - 1 light-emitting diodes LED and n - 1 voltage-dividing resistors r are provided. The n - 1 light-emitting diodes LED are respectively denoted as light-emitting diode LED1, light-emitting diode LED2,..., light-emitting diode LEDn-1, and the voltage-dividing resistors r are respectively denoted as voltage-dividing resistor r1, voltage-dividing resistor r2,..., voltage-dividing resistor rn-1; after one ends of the light-emitting diode LED1, light-emitting diode LED2,..., light-emitting diode LEDn-1 are connected in parallel, they are electrically connected to the emitter of the triode Q1. The light-emitting diode LED1, light-emitting diode LED2,..., light-emitting diode LEDn-1 are respectively connected to one ends of the corresponding voltage-dividing resistor r1, voltage-dividing resistor r2,..., voltage-dividing resistor rn-1, and the other ends of the voltage-dividing resistor r1, voltage-dividing resistor r2,..., voltage-dividing resistor rn-1 are respectively electrically connected to the first IO port IO1, the second IO port IO2,..., the (n - 1)th IO port IOn-1; the base of the triode Q1 is electrically connected to the nth IO port IOn through the tube voltage-dividing resistor r0.

[0041] Preferably, n = 5, and 4 light-emitting diodes LED and 4 voltage-dividing resistors r are provided. The 4 light-emitting diodes LED are respectively denoted as light-emitting diode 1 LED1, light-emitting diode 2 LED2, light-emitting diode 3 LED3, and light-emitting diode 4 LED4, and the 4 voltage-dividing resistors r are respectively denoted as voltage-dividing resistor 1 r1, voltage-dividing resistor 2 r2, voltage-dividing resistor 3 r3, and voltage-dividing resistor 4 r4. The emitter of the triode Q1 is electrically connected to the positive electrodes of the light-emitting diode 1 LED1, light-emitting diode 2 LED2, light-emitting diode 3 LED3, and light-emitting diode 4 LED4 respectively. The negative electrodes of the light-emitting diode 1 LED1, light-emitting diode 2 LED2, light-emitting diode 3 LED3, and light-emitting diode 4 LED4 are electrically connected to one end of the voltage-dividing resistor 1 r1, voltage-dividing resistor 2 r2, voltage-dividing resistor 3 r3, and voltage-dividing resistor 4 r4 respectively. The other ends of the voltage-dividing resistor 1 r1, voltage-dividing resistor 2 r2, voltage-dividing resistor 3 r3, and voltage-dividing resistor 4 r4 are electrically connected to the first IO port IO1, second IO port IO2, third IO port IO3, and fourth IO port IO4 respectively. The base of the triode Q1 is electrically connected to the fifth IO port IO5 through the tube voltage-dividing resistor r0.

[0042] Through time-sharing control by a preset program in the control chip, the SEG port of the indicator light or digital tube, that is, the IO port corresponding to the n - 1 segment light-emitting diodes, can be multiplexed to the key IO port, which can further reduce the number of IO used and improve the reliability of the display signal in the circuit.

[0043] Working principle:

[0044] Taking n = 5 as an example, when the microwave oven is powered on, a time-sharing control program is preset in the control chip of the computer board. In the first stage, IO5 (which can generally be defined as the COM port of the indicator light or digital tube, that is, the common control port) outputs a low level, the triode Q1 is cut off, and all the indicator lights are turned off. At this time, the key scanning program is entered. Then the controller's IO1 outputs a low level, delays for a period of time, and IO2, IO3, and IO4 are configured as input pull-ups (that is, configured as high levels). Then when SW2 in row 1 is pressed, column 2 will become a low level, and then IO2 will become a low level due to the conduction of the diode D2 and filtering through R2 and C2. If SW3 in row 1 is pressed, column 3 will become a low level, and then IO3 will become a low level due to the conduction of the diode D3 and filtering through R3 and C3. If SW4 in row 1 is pressed, column 4 will become a low level, and then IO4 will become a low level due to the conduction of the diode D4 and filtering through R4 and C4. The voltage changes of IO2 to IO4 are read in sequence, and debounced for a certain time or number of times. If it is a high level, no key is pressed. If it changes from a high level to a low level, the key is pressed, that is, it can be recognized whether the 3 keys SW2 to SW4 in row 1 are pressed. Since IO1 is used for output and the feedback line is also at IO1, SW1 cannot be recognized, so no key is actually placed at this position.

[0045] Similarly, when IO2 outputs a low level and delays for a period of time, IO1, IO3, and IO4 are configured as input pull-ups (i.e., configured as high levels). By sequentially reading the level states of IO1, IO3, and IO4, the SW5, SW7, and SW8 buttons can be recognized; when IO3 outputs a low level and delays for a period of time, IO1, IO2, and IO4 are configured as input pull-ups (i.e., configured as high levels). By sequentially reading the level states of IO1, IO2, and IO4, the SW9, SW10, and SW12 buttons can be recognized; when IO4 outputs a low level and delays for a period of time, IO1, IO2, and IO3 are configured as input pull-ups (i.e., configured as high levels). By sequentially reading the level states of IO1, IO2, and IO3, the SW13, SW14, and SW15 buttons can be recognized.

[0046] Further, after recognizing the button states, it enters the second stage to control the indicator light or the digital tube display. At this time, IO5 outputs a high level, then the CE pole of the triode Q1 conducts, outputs low for the indicator light or digital tube segment to be lit, and outputs high for the indicator light or digital tube segment not to be lit, that is, outputs the required level to IO1 - IO4, then the display effect is achieved.

[0047] Subsequently, the control of the first and second stages is alternately performed in sequence, and the button detection and display can be realized. Since the program scanning frequency is fast enough, even if the indicator light briefly goes out during the button scanning process, the human eye still sees the indicator light or the screen as lit, which can meet the usage requirements.

[0048] Since 4 IOs can recognize 4 * 3 = 12 buttons, and n IOs can recognize n * (n - 1) buttons. In addition, these n IOs can continue to be multiplexed for the ports of the indicator light or the digital tube, greatly reducing the number of IOs used compared to the traditional matrix button control method. For example, for 25 buttons, the traditional method requires 10 IOs, but now only 6 IOs are needed. In addition, these 6 IOs can be multiplexed for the control of the indicator light or the digital tube segment ports, greatly saving the chip IO port resources and further reducing the cost.

[0049] A microwave oven, the microwave oven includes the circuit for saving the IO ports of the computer board as described above, and the circuit is arranged on the computer board inside the microwave oven to achieve the function of reducing the production cost of the microwave oven.

[0050] In the present utility model, for any microwave oven, it may include the circuit structure for saving the computer board IO ports described in this embodiment. Based on the relevant structures and assembly relationships of the column multiplexing module 4 and the matrix key module 3 provided in this embodiment, the microwave oven further includes conventional components such as a magnetron, a power transformer, and a furnace cavity. Since they are all prior arts, no further elaboration will be made herein.

[0051] The foregoing are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A circuit for saving IO ports on a computer board, characterized in that: The single-chip computer module (1) comprises a single-chip computer module (1), a filter module (2), a matrix key module (3), a column multiplexing module (4) and a display module circuit (5); the single-chip computer module (1) is electrically connected to the matrix key module (3) and the column multiplexing module (4) through the filter module (2); the single-chip computer module (1) is electrically connected to the display module circuit (5); wherein the single-chip computer module (1) comprises a control chip, the control chip comprises an IO port, and the control chip is electrically connected to the filter module (2) and the display module circuit (5) through the IO port; and n IO ports are provided.

2. A circuit for saving IO ports of a computer board according to claim 1, characterized in that: The display module circuit (5) comprises an indicator light display circuit or a digital tube display circuit.

3. A circuit for saving IO ports of a computer board according to claim 1, characterized in that: The filtering module (2) is a key input RC filtering module.

4. A circuit for saving IO ports of a computer board according to claim 1, characterized in that: The n IO ports are respectively recorded as a first IO port IO1, a second IO port IO2, ..., and an n-th IO port IOn. The single-chip computer module (1) is electrically connected to the filter module (2) and the display module circuit (5) through the first IO port IO1, the second IO port IO2, ..., and the n-1th IO port IOn-1. The single-chip computer module (1) is electrically connected to the display module circuit (5) through the n-th IO port IOn.

5. The circuit for saving IO ports of a computer board according to claim 1, characterized in that: The filter module (2) comprises a filter capacitor C and a filter resistor R, one end of the filter capacitor C is electrically connected to one end of the filter resistor R and the IO port respectively, the other end of the filter capacitor C is grounded, and the other end of the filter resistor R is electrically connected to the matrix key module (3) and the column multiplexing module (4) respectively.

6. A circuit for saving IO ports of a computer board according to claim 5, characterized in that: The matrix key module (3) comprises m keys, and the m keys are arranged in the form of a matrix, where m is a positive integer.

7. The circuit for saving IO ports of a computer board according to claim 1, characterized in that: The display module circuit (5) comprises a transistor Q1, a light emitting diode LED, and a voltage dividing resistor r; the base of the transistor Q1 is electrically connected to the single chip computer module (1) via the voltage dividing resistor r0; the collector of the transistor Q1 is connected to VCC or a power supply, and the emitter of the transistor Q1 is connected to the single chip computer module (1) via the light emitting diode LED and the voltage dividing resistor r in sequence.

8. A microwave oven, characterized in that: The microwave oven comprises a circuit for saving IO ports of a computer board according to any one of claims 1 to 7, and the circuit is arranged on a computer board in the microwave oven.

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