Electronic device and signal transmission control method

Abstract

The invention provides electronic equipment and a signal transmission control method. The electronic equipment comprises a main control chip and a communication serial port, the electronic equipment can be in communication connection with external equipment through the communication serial port, the main control chip is connected with the communication serial port through a universal asynchronous receiving and transmitting serial port, and the universal asynchronous receiving and transmitting serial port comprises a receiving signal line used for the communication serial port to transmit signals to the main control chip. The transmitting signal line is used for the main control chip to transmit signals to the communication serial port; the electronic equipment further comprises a detection module, the input end of the detection module is connected with the receiving signal line, and the output end of the detection module is connected with the detection signal end of the main control chip. According to the invention, the detection module is arranged to detect the level signal on the receiving signal line so as to judge whether signal crosstalk exists or not, so that the crosstalk is eliminated, and the reliability of signal transmission can be improved.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to an electronic device and a signal transmission control method. Background Art

[0002] Serial communication, as a common standard information transmission method, is usually applied to the transmission of data signals. According to the transmission line crosstalk theory, on a pair of coupled lines, when a signal is generated on one side, crosstalk noise will be generated on the other line. Crosstalk always exists and cannot be eliminated, but only weakened. Therefore, when the crosstalk signal is relatively high, it may affect the normal transmission of the signal, resulting in abnormal response between devices. Summary of the Invention

[0003] Embodiments of this application provide an electronic device and a signal transmission control method to solve the problem that crosstalk of serial port signals affects signal transmission.

[0004] In a first aspect, embodiments of the present invention provide an electronic device, including a main control chip and a communication serial port. The electronic device can be communicatively connected to an external device through the communication serial port. The main control chip is connected to the communication serial port through a universal asynchronous receiver / transmitter serial port. The universal asynchronous receiver / transmitter serial port includes a receiving signal line for the communication serial port to transmit a signal to the main control chip, and a transmitting signal line for the main control chip to transmit a signal to the communication serial port.

[0005] The electronic device further includes a detection module. The input end of the detection module is connected to the receiving signal line, and the output end of the detection module is connected to the detection signal end of the main control chip.

[0006] In some embodiments, the electronic device further includes a filtering circuit. The filtering circuit is disposed between the communication serial port and the external device. The filtering circuit includes a switching switch and a low-pass filtering module.

[0007] The filtering circuit is configured such that in the filtering mode, the switching switch switches the filtering circuit to connect the communication serial port to the external device through the low-pass filtering module.

[0008] The filtering circuit is configured such that in the non-filtering mode, the switching switch switches the filtering circuit to connect the communication serial port to the external device.

[0009] In some embodiments, the low-pass filtering module includes a capacitor-resistor low-pass filtering module. The capacitor-resistor low-pass filtering module includes a first selector, a plurality of filtering resistors, a second selector, and a plurality of filtering capacitors. Among them, at least some of the resistors of the plurality of filtering resistors have different resistance values, and at least some of the capacitors of the plurality of filtering capacitors have different capacitance values.

[0010] The first selector is connected to the main control chip, and the first selector is configured to switch one of the multiple filter resistors to a connected state under the control of the main control chip;

[0011] The second selector is connected to the main control chip, and the second selector is configured to switch one of the multiple filter capacitors to a connected state under the control of the main control chip.

[0012] In some embodiments, the electronic device further includes a double - pole switch, which is disposed between the communication serial port and the external device, and the double - pole switch has a first connection mode and a second connection mode;

[0013] In the first connection mode, the double - pole switch controls the ground wire to be connected to the ground terminal of the communication serial port, and the input signal line to be connected to the receive signal terminal of the communication serial port;

[0014] In the second connection mode, the double - pole switch controls the ground wire to be connected to the receive signal terminal of the communication serial port, and the input signal line to be connected to the ground terminal of the communication serial port.

[0015] In some embodiments, a differential converter is further included. The differential converter is connected to the universal asynchronous transceiver serial port, and the differential converter is configured to communicate with the external device through differential signals, and the connector of the differential converter multiplexes the connector of the communication serial port.

[0016] In a second aspect, an embodiment of the present application provides a signal transmission control method, which is applied to the electronic device described in any item of the first aspect. The method includes:

[0017] The main control chip sends a test signal to the external device through the receive signal line;

[0018] In the case that the external device does not feedback a signal to the electronic device, the detection module detects the maximum and minimum values of the noise voltage on the receive signal line;

[0019] In the case that the maximum and minimum values of the noise voltage are greater than a preset noise voltage threshold, it is confirmed that crosstalk exists in the serial port transmission;

[0020] In the case that the maximum and minimum values of the noise voltage are not greater than a preset noise voltage threshold, it is confirmed that no crosstalk exists in the serial port transmission.

[0021] In some embodiments, in the case of being applied to the electronic device described in the second item of the first aspect, the method includes:

[0022] In the case that crosstalk exists in the serial port transmission, control the switching switch to switch the filter circuit to the filtering mode.

[0023] In some of these embodiments, when applied to the electronic device described in the third item of the first aspect, the method further includes:

[0024] The main control chip controls the first selector to switch the filter resistor in the connected state and / or controls the second selector to switch the filter capacitor in the connected state;

[0025] The main control chip iteratively executes the steps of switching the filter capacitor and / or the filter capacitor, and sending a test signal and detecting the maximum and minimum values of the noise voltage until there is no crosstalk in the serial port transmission.

[0026] In some of these embodiments, when applied to the electronic device described in the fourth item of the first aspect, the method further includes:

[0027] When there is crosstalk in the serial port transmission, control the double - path switch to switch from the first connection mode to the second connection mode.

[0028] In some of these embodiments, when applied to the electronic device described in the fifth item of the first aspect, the method further includes:

[0029] When there is crosstalk in the serial port transmission, after the differential converter converts the signal transmitted by the universal asynchronous receiver / transmitter serial port into a differential signal, communicate with the external device through the differential signal.

[0030] The detection module in the embodiments of the present invention detects the level signal on the received signal line to determine whether there is signal crosstalk, so that when there is signal crosstalk, the crosstalk can be further eliminated, and the reliability of signal transmission can be improved. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 is a schematic structural diagram of an electronic device in an embodiment of the present application;

[0033] Figure 2 is a schematic structural diagram of an electronic device in another embodiment of the present application;

[0034] Figure 3 is a schematic structural diagram of a low - pass filter module in an embodiment of the present application;

[0035] Figure 4It is a schematic structural diagram of an electronic device in another embodiment of the present application;

[0036] Figure 5 It is a schematic structural diagram of an electronic device in another embodiment of the present application;

[0037] Figure 6 It is a schematic flowchart of a signal transmission control method in an embodiment of the present application. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0039] The terms "first", "second", etc. in the embodiments of the present application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices. In addition, in the present application, "and / or" is used to represent at least one of the connected objects. For example, A and / or B and / or C represent seven situations including A alone, B alone, C alone, A and B existing together, B and C existing together, A and C existing together, and A, B, and C existing together.

[0040] The embodiments of the present application provide an electronic device.

[0041] As Figure 1 shown, in the embodiments of the present invention, the electronic device 100 includes a main control chip 101 and a communication serial port 102, and the electronic device 100 can communicate with an external device 200 through the communication serial port 102.

[0042] Serial ports are usually used for connections between two devices. Common serial communication protocols usually include UART (Universal Asynchronous Receiver / Transmitter) and RS232 (a serial communication interface standard). Among them, the operating level of UART is TTL (Transistor-Transistor Logic) level, which is usually applied to short-distance data transmission scenarios such as inside a single electronic device. The RS232 level is ±3V to ±15V, with a relatively high voltage and better attenuation resistance, making it more suitable for long-distance transmission. Therefore, generally, the RS232 serial port is selected between two electronic devices with a large distance apart.

[0043] As Figure 1 shown, in the technical solution of this embodiment, inside the electronic device 100, the main control chip 101 and the communication serial port 102 are connected through a UART serial port, and the electronic device 100 is connected to the external device 200 through an RS232 serial port. That is to say, the communication serial port 102 of the electronic device 100 and the external device 200 are communicatively connected based on the RS232 serial port.

[0044] The main control chip 101 is connected to the communication serial port 102 through a UART serial port. In this embodiment, the UART serial port between the main control chip 101 and the communication serial port 102 includes a receiving signal line UART-Rx for the communication serial port 102 to transmit signals to the main control chip 101, and a transmitting signal line UART-Tx for the main control chip 101 to transmit signals to the communication serial port 102. The RS232 serial port between the communication serial port 102 and the external device 200 includes an output signal line Tx, an input signal line Rx, and a common ground wire GND.

[0045] According to the transmission line crosstalk theory, on a pair of coupled lines, crosstalk noise will be generated on the other line when a signal is generated on one side. The crosstalk closer to the signal source end is called near-end crosstalk, and the one farther from the source end is called far-end crosstalk. The intensity of the crosstalk signal is related to the distance between the two lines, the length of the coupling, and the signal intensity. Crosstalk always exists and cannot be eliminated, only weakened.

[0046] In high-speed signal transmission, if the impedance on the line is not matched, such as when the impedance increases, signal reflection will occur. In the case of an open circuit at the end, the reflection coefficient is 1, which means that when a 1V signal reaches the open end, the signal transient voltage will suddenly change to 2V.

[0047] In actual engineering application scenarios, twisted-pair cables, especially network cables, are widely used. When a network cable is applied to a serial port, due to their close spacing and the high voltage amplitude of RS232 signals, crosstalk noise is extremely likely to occur under such conditions according to the crosstalk characteristics. That is, when a signal is generated on the Tx line, crosstalk noise can be generated on the Rx line, and vice versa. When the grounding at both ends of the serial communication device is poor, or one end is floating, or the other end is powered off after connection, due to the reflection effect of the signal, the crosstalk signal will be reflected at the position where the impedance becomes larger, further raising the original crosstalk signal. When the amplitude is high enough, the noise signal will be detected. This will bring the following problems:

[0048] (1) When the host sends data to the external device on the opposite side, even if the external device does not send data to the host, the host will receive the noise signal caused by its own transmitted signal. At this time, the noise is the superposition of the near-end crosstalk signal and the reflection effect of this crosstalk signal, resulting in misdetection by the host.

[0049] (2) When the host sends data to the external device on the opposite side, and at the same time the external device 200 also sends data to the host, the data received by the host at this time is a signal that is the superposition of the valid data and the noise signal, making the host unable to correctly respond to the external device.

[0050] In the technical solution of this embodiment, the electronic device 100 further includes a detection module 103. The input end of the detection module 103 is connected to the receiving signal line UART-Rx, and the output end of the detection module 103 is connected to the detection signal end of the main control chip 101.

[0051] The embodiment of the present application provides a signal transmission control method, and the method includes:

[0052] The main control chip sends a test signal to the external device through the receiving signal line;

[0053] In the case where the external device does not feedback a signal to the electronic device, the detection module detects the maximum and minimum values of the noise voltage on the receiving signal line;

[0054] In the case where the maximum and minimum values of the noise voltage are greater than a preset noise voltage threshold, it is confirmed that crosstalk exists in the serial port transmission;

[0055] In the case where the maximum and minimum values of the noise voltage are not greater than a preset noise voltage threshold, it is confirmed that no crosstalk exists in the serial port transmission.

[0056] In this embodiment, the interference intensity is first tested. The test signal in this embodiment can be set as needed. The main control chip 101 sends a test signal for a certain period of time through UART-Tx. In an exemplary embodiment, the test signal is a square wave signal with a frequency of 1 KHz and a duty cycle of 50%. It can be understood that the frequency, duty cycle, etc. of the test signal can be adjusted as needed. In this embodiment, it is only for illustrative purposes and does not limit the format of the test signal.

[0057] The external device 200 opposite is configured not to send data. In this way, there is no feedback signal from the external device 200 opposite, that is, only the signals on UART-Tx and Tx change under the current conditions. When there is crosstalk or reflection noise in the serial port, a voltage signal will be generated in Rx, and then a voltage signal will be generated on UART-Rx.

[0058] In the technical solution of this embodiment, a detection module 103 for collecting voltage signals is further added to the path of UART-Rx to collect the voltage on UART-Rx through the detection module 103. This signal is split into two paths. One path enters the UART controller of the serial port controller of the main control chip 101, and the other path is detected by the detection module 103 and then enters the ADC (Analog-to-Digital Converter) module of the main control chip 101.

[0059] The output end of the detection module 103 is connected to the detection signal end of the main control chip 101. Specifically, the detection module 103 first provides the detected voltage signal to the ADC module of the main control chip 101 to convert the collected voltage signal into a digital signal as the noise voltage. The maximum value of the noise voltage refers to the maximum value of the noise voltage within a certain period of time (for example, it can be the test period). During implementation, the main control chip 101 compares the detected noise voltage with a preset noise voltage threshold and determines whether there is crosstalk in the serial port transmission according to the comparison result.

[0060] When the maximum value of the noise voltage is greater than the preset noise voltage threshold, it is confirmed that there is crosstalk in the serial port transmission; when the maximum value of the noise voltage is not greater than the preset noise voltage threshold, it is confirmed that there is no crosstalk in the serial port transmission.

[0061] The preset noise voltage threshold can be set as needed. Exemplarily, it can be set to different values such as 5%, 6%, 10% of the UART serial port working voltage, etc. In this embodiment, the specific setting size of the preset noise voltage threshold is not further limited.

[0062] Such as Figure 2As shown, in some of these embodiments, the electronic device 100 further includes a filtering circuit disposed at the communication serial port 102. The filtering circuit includes a switching switch 1041 and a low-pass filtering module 1042. The filtering circuit is configured such that in the filtering mode, the switching switch 1041 switches the filtering circuit to connect the communication serial port 102 to the external device 200 through the low-pass filtering module 1042. The filtering circuit is configured such that in the non-filtering mode, the switching switch 1041 switches the filtering circuit to connect the communication serial port 102 to the external device 200.

[0063] In some of these embodiments, the method includes:

[0064] When there is crosstalk in the serial port transmission, control the switching switch 1041 to switch the filtering circuit to the filtering mode.

[0065] In signal transmission, it takes a certain amount of time for a signal to change from "0" to "1". This changing stage is called the rising edge. The shorter the rising edge time, the more high-frequency components the signal contains, and the influence of high-frequency signals on crosstalk and signal reflection is stronger than that of low-frequency signals.

[0066] As Figure 2 shown, in this embodiment, when in the non-filtering mode, the switching switch 1041 switches to the Figure 2 contact above shown. At this time, the low-pass filtering module 1042 is in the off state. That is to say, the communication serial port 102 and the external device 200 are directly connected through Tx, and the communication serial port 102 directly sends a signal to the external device 200 through Tx.

[0067] When there is crosstalk in the serial port transmission, the switching switch 1041 switches to the filtering mode. That is to say, the switching switch 1041 switches to the Figure 2 contact below shown. At this time, the low-pass filtering module 1042 is connected to Tx. That is to say, the signal sent by the communication serial port 102 is filtered by the low-pass filtering module 1042 and then sent to the external device 200.

[0068] In some of these embodiments, as Figure 3 shown, the low-pass filtering module 1042 is specifically an RC (capacitor-resistor) low-pass filtering module 1042. The RC low-pass filtering module 1042 includes a capacitor and a resistor. Among them, the resistor is connected in series in the circuit, one end of the capacitor is connected to one end of the resistor, and the other end is grounded.

[0069] In this embodiment, the filtering circuit selects the RC low-pass filtering module 1042. The cut-off frequency f c of the RC low-pass filtering module 1042 is:

[0070]

[0071] Among them, R is the resistance value of the filter resistor 10422, and C is the capacitance value of the filter capacitor 10424.

[0072] The RC low-pass filter module 1042 includes a first selector 10421, a plurality of filter resistors 10422, a second selector 10423, and a plurality of filter capacitors 10424. Among them, at least some of the resistances of the plurality of filter resistors 10422 are different, and at least some of the capacitances of the plurality of filter capacitors 10424 are different.

[0073] In some embodiments, the method further includes:

[0074] The main control chip controls the first selector to switch the filter resistor in the connected state and / or controls the second selector to switch the filter capacitor in the connected state;

[0075] The main control chip iteratively executes the steps of switching the filter capacitor and / or the filter capacitor, sending a test signal, and detecting the maximum value of the noise voltage until there is no crosstalk in the serial port transmission.

[0076] The first selector 10421 is connected to the main control chip 101. The first selector 10421 is configured to switch one of the plurality of filter resistors 10422 to the connected state under the control of the main control chip 101; the second selector 10423 is connected to the main control chip 101. The second selector 10423 is configured to switch one of the plurality of filter capacitors 10424 to the connected state under the control of the main control chip 101.

[0077] It can be understood that the first selector 10421 can select different filter resistors 10422 as the filter resistor 10422 of the RC low-pass filter module 1042, and the second selector 10423 can select different filter capacitors 10424 as the filter capacitor 10424 of the RC low-pass filter module 1042. In this way, under the control of the main control chip 101, the first selector 10421 and the second selector 10423 can select filter capacitors 10424 with different capacitance values and filter resistors 10422 with different resistance values to form the RC low-pass filter module 1042, so as to provide an RC low-pass filter module 1042 with different cut-off frequencies. Thus, high-frequency signal components above the cut-off frequency are filtered out, and signals below the cut-off frequency are retained.

[0078] During implementation, the control pins A0 and A1 of the first multiplexer 10421 are connected to the control ports GPIO (General Purpose Input / Output) of the main control chip 101. By controlling the levels of A0 and A1, different filter resistors 10422 can be selected through the control of the first multiplexer 10421. Similarly, the control pins B0 and B1 of the second multiplexer 10423 are connected to the control ports GPIO of the main control chip 101. By controlling the levels of B0 and B1, different filter resistors 10422 can be selected through the control of the first multiplexer 10421.

[0079] During implementation, different numbers of filter capacitors 10424 and filter resistors 10422 can be selected. At the same time, the first multiplexer 10421 and the second multiplexer 10423 with corresponding channels are set, so as to realize the provision of the RC low-pass filter module 1042 with different cut-off frequencies.

[0080] After switching different filter capacitors 10424 and / or filter resistors 10422, a test signal and the maximum and minimum values of the detected noise voltage are sent again to detect whether crosstalk still exists in the current working state during serial port transmission. When crosstalk exists, the switching of the filter capacitors 10424 and / or filter resistors 10422 is continued, and further testing and detection are carried out until crosstalk does not exist in serial port transmission, so that the noise does not affect data sending and data receiving between the electronic device 100 and the external device 200.

[0081] It should be understood that since the filter circuit will filter out some high-frequency information, the signal voltage of Tx will be weakened compared with that before filtering. When the values of R and C are not selected properly and the signal is over-filtered, the information of Tx may be weakened too much, resulting in the inability of the external device 200 on the opposite side to detect the sent signal. Therefore, appropriate values of R and C need to be selected according to the working environment.

[0082] As Figure 4 shown, in some embodiments, the electronic device 100 further includes a double-pole switch 105. The double-pole switch 105 is arranged at the communication serial port 102, and the double-pole switch 105 has a first connection mode and a second connection mode;

[0083] In the first connection mode, the double-pole switch 105 controls the ground wire to be connected to the ground wire terminal of the communication serial port 102, and the input signal wire is connected to the received signal terminal of the communication serial port 102;

[0084] In the second connection mode, the double-pole switch 105 controls the ground wire to be connected to the received signal terminal of the communication serial port 102, and the input signal wire is connected to the ground wire terminal of the communication serial port 102.

[0085] In some of these embodiments, the method further includes:

[0086] When there is crosstalk in the serial port transmission, control the dual - path switch to switch from the first connection mode to the second connection mode.

[0087] In the technical solution of this embodiment, the dual - path switch 105 can achieve two connection methods. It can be understood that under the first connection method and the second connection method, the connection states of GND and Rx are exchanged.

[0088] It should be understood that when using a tightly - coupled connection method such as twisted - pair wires to connect Tx and Rx, crosstalk noise will increase, and this connection method is widely used in actual applications. In this embodiment, by adjusting the data type transmitted in the twisted - pair wires through circuit design, the transmit line Tx and the receive line Rx are separated to reduce crosstalk noise.

[0089] Specifically, in this embodiment, at the serial port output, a dual - path switch 105 is added and placed on the Rx and GND lines respectively. When actually in use, when Tx and Rx are not on a pair of twisted - pair wires, the crosstalk interference is relatively small, and at this time, the circuit is not switched. When Tx and Rx are connected together with twisted - pair wires and the crosstalk effect is large, the main control chip 101 controls the dual - path switch 105 to perform a switching operation. After switching, in the same pair of twisted - pair wires, the signals transmitted are TX and GND. The crosstalk noise of TX will be more coupled into the ground loop. At this time, the Rx signal is separated from the original twisted - pair wire, and the distance from the Tx wire also becomes larger, and the overall crosstalk noise will be weakened.

[0090] As Figure 5 shown, in some of these embodiments, a differential converter 106 is further included. The differential converter 106 is connected to the universal asynchronous transceiver serial port, and the differential converter 106 is configured to communicate with the external device 200 through differential signals, and the connector of the differential converter 106 multiplexes the connector of the communication serial port 102.

[0091] In some of these embodiments, the method further includes:

[0092] When there is crosstalk in the serial port transmission, after the differential converter converts the signal transmitted by the universal asynchronous transceiver serial port into a differential signal, it communicates with the external device through the differential signal.

[0093] The differential signal obtains data by comparing the voltage difference between differential pairs. External interference is generally applied to both differential pairs at the same time, but the interference will be automatically filtered out through the voltage - difference calculation. Therefore, compared with the serial - port signal, the differential - signal transmission has strong anti - interference ability. In the technical solution of this embodiment, during implementation, the differential signal is used to replace the serial - port transmission between the electronic device 100 and the external device 200 to avoid interference.

[0094] Specifically, during implementation, the UART signal with TTL level is converted into a differential pair and then communicates with the external device 200 in the opposite direction through the differential signal. The differential signal can be selected from USB (Universal Serial Bus), Ethernet, RS485 (an interface standard), etc. During implementation, inside the electronic device 100, the signal still transmits in the form of a serial port signal. For the outside of the electronic device, when there is crosstalk in the serial port transmission between the electronic device 100 and the external device 200, after the serial port signal is converted into a differential signal by the differential converter 106, data transmission is carried out between the differential converter and the external device 200.

[0095] Further, in some embodiments, since the commonly used connector types for the RS232 serial port are network ports and DB9 (D-type data interface connectors), which are the same as the conventional connectors used for RS485 communication, the connectors can be shared in the case of converting the serial port to RS485.

[0096] As Figure 6 shown, the technical solution of this embodiment can be summarized as follows: during implementation, first, test whether there is crosstalk in the serial port transmission. Specifically, the host sends a test signal, and the opposite host does not send data. In this way, the signal received by the host is a noise signal, or an interference signal. When the noise signal is greater than the threshold, after enabling crosstalk filtering, data is transmitted through the serial port. If the noise signal is not greater than the threshold, data can be directly transmitted through the serial port.

[0097] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0098] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present application.

[0099] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative rather than restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.

Claims

1. An electronic device, characterized in that, It includes a main control chip and a communication serial port. The electronic device can be communicatively connected to an external device through the communication serial port. The main control chip is connected to the communication serial port through a universal asynchronous receiver / transmitter (UART). The UART includes a receiving signal line for the communication serial port to transmit signals to the main control chip and a transmitting signal line for the main control chip to transmit signals to the communication serial port. The electronic device further includes a detection module. The input end of the detection module is connected to the receiving signal line, and the output end of the detection module is connected to the detection signal end of the main control chip.

2. The electronic device according to claim 1, wherein The electronic device further includes a filtering circuit. The filtering circuit is arranged between the communication serial port and the external device. The filtering circuit includes a switching switch and a low-pass filtering module. The filtering circuit is configured such that in the filtering mode, the switching switch switches the filtering circuit to connect the communication serial port to the external device through the low-pass filtering module. The filtering circuit is configured such that in the non-filtering mode, the switching switch switches the filtering circuit to connect the communication serial port to the external device.

3. The electronic device according to claim 2, wherein The low-pass filtering module includes a capacitor-resistor low-pass filtering module. The capacitor-resistor low-pass filtering module includes a first selector, a plurality of filtering resistors, a second selector, and a plurality of filtering capacitors. Among them, at least some of the resistors of the plurality of filtering resistors have different resistance values, and at least some of the capacitors of the plurality of filtering capacitors have different capacitance values. The first selector is connected to the main control chip. The first selector is configured to switch one of the plurality of filtering resistors to a connected state under the control of the main control chip. The second selector is connected to the main control chip. The second selector is configured to switch one of the plurality of filtering capacitors to a connected state under the control of the main control chip.

4. The electronic device according to claim 1, characterized in that, The electronic device further includes a double-way switch. The double-way switch is arranged between the communication serial port and the external device. The double-way switch has a first connection mode and a second connection mode. In the first connection mode, the double-way switch controls the ground wire to be connected to the ground wire terminal of the communication serial port, and the input signal line to be connected to the receiving signal end of the communication serial port. In the second connection mode, the double-way switch controls the ground wire to be connected to the receiving signal end of the communication serial port, and the input signal line to be connected to the ground wire terminal of the communication serial port.

5. The electronic device according to any one of claims 1 to 3, characterized in that, It further includes a differential converter. The differential converter is connected to the UART. The differential converter is configured to communicate with the external device through differential signals, and the connector of the differential converter multiplexes the connector of the communication serial port.

6. A signal transmission control method, applied to the electronic device described in any one of claims 1 to 5, characterized in that, The method includes: The main control chip sends a test signal to the external device through the receiving signal line. When the external device does not feedback a signal to the electronic device, the detection module detects the maximum and minimum values of the noise voltage on the receiving signal line. When the maximum and minimum values of the noise voltage are greater than a preset noise voltage threshold, it is confirmed that there is crosstalk in the serial port transmission. When the maximum and minimum values of the noise voltage are not greater than a preset noise voltage threshold, it is confirmed that there is no crosstalk in the serial port transmission.

7. The method according to claim 6, wherein When applied to the electronic device described in claim 2, the method includes: When there is crosstalk in the serial port transmission, control the switching switch to switch the filtering circuit to the filtering mode.

8. The method according to claim 7, characterized in that When applied to the electronic device described in claim 2, the method further includes: The main control chip controls the first selector to switch the filtering resistor in the connected state and / or controls the second selector to switch the filtering capacitor in the connected state; The main control chip iteratively executes the steps of switching the filtering capacitor and / or the filtering capacitor, and sending a test signal and detecting the maximum value of the noise voltage until there is no crosstalk in the serial port transmission.

9. The method according to claim 6, characterized in that, When applied to the electronic device described in claim 4, the method further includes: When there is crosstalk in the serial port transmission, control the dual-channel switch to switch from the first connection mode to the second connection mode.

10. The method according to claim 6, wherein When applied to the electronic device described in claim 5, the method further includes: When there is crosstalk in the serial port transmission, the differential converter converts the signal transmitted by the universal asynchronous receiver / transmitter serial port into a differential signal, and then communicates with the external device through the differential signal.

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