Two-way communication interface device based on PWM (Pulse Width Modulation) signal
By employing a bidirectional communication interface device based on PWM signals in the vehicle air conditioning system, bidirectional communication of PWM signals can be achieved using a single input/output pin. This solves the problem of complex wiring in the traditional dual-wire control mode, and improves production efficiency and ease of maintenance.
Patent Information
- Application Number
- CN202423212366.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-25
AI Technical Summary
In traditional vehicle air conditioning systems, the dual-wire control mode of PWM signals leads to complex wiring, increases production costs, and reduces the ease of maintenance.
A bidirectional communication interface device based on PWM signals is adopted, which realizes bidirectional communication of PWM signals through a single input/output pin. It includes an input/output module, a PWM signal transmitting module and a receiving module, and uses electronic components such as transistors and capacitors to realize single-wire transmission and feedback of signals.
It simplifies wiring, reduces production costs, improves production efficiency and ease of maintenance, and achieves stable and independent signal transmission.
Smart Images
Figure CN223526708U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to communication technical field especially, it relates to a kind of two-way communication interface device based on PWM signal. BACKGROUND
[0002] In the current vehicle-mounted air conditioning system, there are specific signal requirements for the control of some loads. Especially in the processing of two key signals of PWM (pulse width modulation) control and feedback, the traditional control mode usually adopts a two-wire control mode. This two-wire control mode ensures the stability and independence of signal transmission to some extent, but as the automobile electronic system continues to develop and the degree of integration improves, the problem of complex wiring gradually emerges. Complex wiring not only increases production costs, but also brings many inconveniences in the assembly process of the vehicle and the later maintenance and repair, reducing production efficiency and the convenience of maintenance. SUMMARY
[0003] The utility model aims at overcoming the shortcomings and deficiencies of prior art, and provides a kind of two-way communication interface device based on PWM signal, including input output module, PWM signal sending module and receiving module;
[0004] The input output module includes a single input output pin for connecting with the load, and a control terminal, the input output module can output PWM signal to the load through the input output pin and receive the feedback signal emitted by the load through the input output pin;
[0005] The PWM signal sending module is connected with the control terminal of the input output module, for outputting PWM signal;
[0006] The receiving module is connected with the control terminal of the input output module, for receiving the feedback signal emitted by the load.
[0007] Preferably, it includes a first switch module and a level conversion module;
[0008] The input end of the first switch module is connected with the PWM signal sending module, and the output end is connected with the level conversion module, the first switch module is used to control the opening and closing state of itself according to the voltage size of PWM signal; Wherein, when the first switch module is in the disconnected state, the level conversion module outputs high level; When the switch module is in the closed state, the level conversion module outputs low level;
[0009] The level conversion module is connected with the input output module, when the level conversion module outputs high level, the input output module can send feedback signal to the level conversion module.
[0010] Preferably, the receiving module comprises a protection module, which is connected with the level conversion module.
[0011] Preferably, the receiving module comprises a second switch module, which is connected with the protection module and used for controlling the on-off state of itself according to the feedback signal sent by the input-output module.
[0012] Preferably, the PWM signal sending module comprises an anti-interference module, which is connected with the switch module and used for controlling the switch module to be in the off state.
[0013] Preferably, the PWM signal sending module comprises an over-current protection module, which is connected with the switch module.
[0014] Preferably, the first switch module and the second switch module are both transistors, and the first switch module adopts an open-drain output mode.
[0015] Preferably, the feedback signal is a low-voltage signal.
[0016] Preferably, the receiving module comprises a first filter module and a second filter module, the first filter module and the second filter module are respectively a first capacitor C1 and a second capacitor C2, the first capacitor C1 is connected with the first switch module and the level conversion module respectively, and the second capacitor C2 is connected with the second switch module.
[0017] The utility model discloses a beneficial effect: through the control end of input-output module respectively with PWM signal sending module, receiving module connection, the PWM signal that PWM signal sending module sent is transmitted from the single input-output pin of input-output module to load, and the feedback signal that load sends is transmitted from the single input-output pin of input-output module to receiving module, thereby accomplishing the transceiving bidirectional communication of single line PWM signal. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, below will be to the drawing needed to be used in the embodiment or prior art description simple introduction, obviously, the drawing in the following description only some embodiments of the utility model, for those skilled in the art, under the premise of not paying the creative labor, according to these drawings, other drawings still belong to the scope of the utility model obtained.
[0019] Fig. 1 It is the principle block diagram of the utility model;
[0020] Fig. 2 It is the circuit diagram of the embodiment of the utility model. DETAILED DESCRIPTION
[0021] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.
[0022] It should be noted that all uses of "first" and "second" in the embodiments of this utility model are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of this utility model. Subsequent embodiments will not explain this in detail.
[0023] The directional and positional terms used in this utility model, such as "up," "down," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side," are merely for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.
[0024] like Figs. 1-2 As shown in the figure, a bidirectional communication interface device based on PWM signal is provided in an embodiment of the present invention, including an input / output module, a PWM signal transmitting module and a receiving module;
[0025] The input / output module includes a single input / output pin for connection to a load, and a control terminal. The input / output module can output PWM signals to the load and receive feedback signals from the load through the input / output pin.
[0026] The PWM signal transmitting module is connected to the control terminal of the input / output module and is used to output PWM signals;
[0027] The receiving module is connected to the control terminal of the input / output module and is used to receive feedback signals from the load.
[0028] It is understandable that the control terminal of the input / output module is connected to the PWM signal transmitting module and the receiving module respectively. The PWM signal sent by the PWM signal transmitting module is transmitted from a single input / output pin of the input / output module to the load, and the feedback signal sent by the load is transmitted from a single input / output pin of the input / output module to the receiving module, thereby completing bidirectional communication on a single line.
[0029] like Fig. 2 In this embodiment, the PWM terminal is a single input / output pin of the input / output module, used to transmit PWM signals and feedback signals; the OUT terminal is the output terminal of the PWM signal transmitting module, which is connected to the control center, and the control center outputs the corresponding PWM signal; the IN terminal is the input terminal of the receiving module, which is connected to the control center and used to transmit feedback signals to the control center.
[0030] The first switch module and the level conversion module are included.
[0031] The input end of the first switch module is connected with the PWM signal sending module, and the output end is connected with the level conversion module, and the first switch module is used for controlling the opening and closing state of itself according to the voltage size of the PWM signal; wherein, when the first switch module is in the off state, the level conversion module outputs high level; when the switch module is in the closed state, the level conversion module outputs low level.
[0032] The level conversion module is connected with the input and output module, and when the level conversion module outputs high level, the input and output module can send the feedback signal to the level conversion module.
[0033] It can be understood that in the embodiment, when the PWM signal is low, the first switch module is in the closed state; at this time, the level conversion module and the PWM signal sending module are turned on, and the signal output by the level conversion module is low; when the PWM signal is high, the first switch module is in the off state; at this time, the level conversion module and the PWM signal sending module are disconnected, because the pull-up resistor is configured in the level conversion module, so that the output signal is high; the switch opening and closing state of the first switch module is one-to-one corresponding to the voltage size of the level conversion module output signal.
[0034] The first switch module can be any electronic component with switching function, and the level conversion module can be any electronic component with level conversion function or a circuit structure composed of electronic components; in the embodiment, the first switch module is a first transistor Q2, the level conversion module is a pull-up resistor R8, and the first transistor Q2 is in open drain output mode. The utility model discloses a first transistor Q2 as the interface circuit of level conversion receiving and open drain output protection, and the cost is very low, and the performance is good.
[0035] The receiving module includes a protection module, and the protection module is connected with the level conversion module.
[0036] It can be understood that in the embodiment, the protection module is a diode D1, and the diode D1 is connected reversely with the level conversion module, so that when the level conversion module outputs high level, the output signal will not affect the receiving module.
[0037] The receiving module includes a second switch module, and the second switch module is connected with the protection module and is used for controlling the opening and closing state of itself according to the feedback signal sent by the input and output module.
[0038] It can be understood that by connecting the second switch module with the diode D1, the voltage of the level conversion module output signal is made to correspond to the on-off state of the second switch module.
[0039] The first switch module can be any electronic component with a switching function, and in this embodiment, the second switch module is a second transistor Q1.
[0040] The PWM signal sending module includes an anti-interference module, which is connected with the first switch module and used to control the first switch module to be in an off state.
[0041] It can be understood that the anti-interference module can prevent other unstable signals from affecting the first switch module. In this embodiment, the anti-interference module is a sixth resistor R6.
[0042] The PWM signal sending module includes an overcurrent protection module, which is connected with the switch module. The overcurrent protection module can be any electronic component with an overcurrent protection function. In this embodiment, the overcurrent protection module is a third transistor Q3.
[0043] The first switch module and the second switch module are both transistors, and the first switch module adopts an open drain output mode.
[0044] The feedback signal is a low-voltage signal.
[0045] It can be understood that the feedback signal and the sent PWM signal are both input or output from a single input-output pin of the input-output module. Because the first switch module adopts an open drain output mode, and on the basis of this, the pull-up resistor in the level conversion module makes the level conversion module output signal be high when the first switch module is in an off state, and a low-level signal can be captured by the second switch module at this time, and will not affect other modules of the utility model.
[0046] The first filter module and the second filter module are respectively a first capacitor C1 and a second capacitor C2, the first capacitor C1 is connected with the first switch module and the level conversion module respectively, and the second capacitor C2 is connected with the second switch module.
[0047] It can be understood that the PWM end is connected with a load, the first capacitor C1 can filter out the interference of the input signal and ensure that the product has strong anti-static ability, the pull-up resistor R8 provides a high-level default output of the PWM signal, the open drain output ensures the sending of the output signal, and a low-level signal of a specific time can be superimposed as a feedback signal;
[0048] The OUT terminal usually outputs a PWM signal of a specific frequency and a required duty cycle from a control center, and outputs a low-level effective PWM signal to the outside through the first transistor Q2, and the first transistor Q2 is in a saturated state through the matching of the appropriate driving current of the fifth resistor R5, and the sixth resistor R6 provides a low level in a non-working state, so as to ensure that the circuit will not send a false signal due to interference, and the resistor R7 detects the Ids current in the on state of the output first transistor Q2, and when the voltage U between the seventh resistor R7 is greater than 0.7V, the base voltage of the transistor Q3 meets the condition for turning on, so as to forcibly pull down the base control signal of the first transistor Q2, so as to turn off the first transistor Q2, and the purpose of outputting the overcurrent protection is achieved.
[0049] The IN terminal receives a PWM signal, and different data signals are corresponded through the identification of different characteristics of the signal, and the diode D1 uses the one-way conduction characteristic to prevent the interference of the current passing through the pull-up resistor R8, the second resistor R2 and the first resistor R1 to VDD when VCC>VDD, and to solve the problem of excessive static current in the non-working state; when the PWM signal is low, the second transistor Q1 is in the on state through the matching of the first resistor R1 and the second resistor R2, and the third resistor R3 is pulled up to VDD, and the IN terminal is high; when the PWM signal is high, the second transistor Q1 is pulled up to be closed through the first resistor R1 due to the diode D1 being cut off, and the IN terminal is pulled down to be low through the third resistor R3 and the fourth resistor R4, and the second capacitor C2 plays a role of filtering and preventing interference.
[0050] The control center can be any chip with the functions of outputting a PWM signal and accepting a feedback signal.
[0051] Those skilled in the art can understand that all or part of the steps of the methods in the above embodiments can be completed by programs instructing related hardware, and the programs can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc.
[0052] The above disclosure is only the preferred embodiment of the utility model, and of course cannot limit the scope of the utility model, so equivalent changes made according to the utility model claims still belong to the scope covered by the utility model.
[0053] It should be noted that the embodiments of the present application can be realized by hardware, software, or a combination of software and hardware. The hardware portion can be realized by using special logic; the software portion can be stored in a memory and executed by a proper instruction execution system, such as a microprocessor or a specially designed hardware. Those skilled in the art can understand that the above-mentioned devices and methods can be realized by using computer executable instructions and / or included in processor control codes, such as providing such codes on a programmable memory or a data carrier, such as an optical or electronic signal carrier.
[0054] Furthermore, although the operations of the method(s) of the present application are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses any appropriate steps performed in any appropriate order. Additionally or alternatively, certain steps can be performed concurrently, even though described as being performed sequentially. Additionally or alternatively, certain steps can be performed at different times, even though described as being performed sequentially. Additionally or alternatively, certain steps can be omitted, even though described as being performed. Additionally or alternatively, certain steps can be performed in an order different than that described, even though described as being performed sequentially. Additionally or alternatively, certain steps can be performed by different entities than those described, even though described as being performed by a single entity. Additionally or alternatively, certain steps can be performed by a single entity, even though described as being performed by multiple entities. Additionally or alternatively, certain steps can be performed by a combination of entities, even though described as being performed by a single entity. Additionally or alternatively, certain steps can be performed by a combination of entities, even though described as being performed by a single entity.
[0055] While the present application has been described with reference to several particular embodiments, it is not intended to be limited thereby, as modifications can be made by those skilled in the art, with the scope of the present application being measured by the following claims.
Claims
1. A PWM signal based bidirectional communication interface device, characterized by: The input and output module comprises a single input and output pin for connecting with the load and a control terminal, and the input and output module can output PWM signals to the load through the input and output pin and receive feedback signals from the load through the input and output pin. The PWM signal sending module is connected with the control terminal of the input and output module and is used for outputting PWM signals. The receiving module is connected with the control terminal of the input and output module and is used for receiving feedback signals from the load. The first switch module is connected with the PWM signal sending module at the input end and is connected with the level conversion module at the output end, and the first switch module is used for controlling the opening and closing state of itself according to the voltage of the PWM signal; when the first switch module is in the open state, the level conversion module outputs a high level; when the switch module is in the closed state, the level conversion module outputs a low level.
2. The PWM-signal-based bidirectional communication interface apparatus according to claim 1, characterized by: The level conversion module is connected with the input and output module, and when the level conversion module outputs a high level, the input and output module can send feedback signals to the level conversion module. The receiving module comprises a protection module, and the protection module is connected with the level conversion module. The receiving module comprises a second switch module, and the second switch module is connected with the protection module and is used for controlling the opening and closing state of itself according to the feedback signals sent by the input and output module.
3. The PWM signal based bidirectional communication interface apparatus according to claim 2, characterized in that: The PWM signal sending module comprises an anti-interference module, and the anti-interference module is connected with the first switch module and is used for controlling the first switch module to be in the open state.
4. The PWM-signal-based bidirectional communication interface apparatus according to claim 3, characterized in that: The PWM signal sending module comprises an overcurrent protection module, and the overcurrent protection module is connected with the first switch module.
5. The PWM-signal-based bidirectional communication interface apparatus according to claim 1, characterized by: The first switch module and the second switch module are both transistors, and the first switch module adopts an open drain output mode.
6. The PWM-signal-based bidirectional communication interface apparatus according to claim 1, wherein: The feedback signal is a low-voltage signal.
7. The PWM-signal-based bidirectional communication interface apparatus according to claim 4, characterized by: The first filter module and the second filter module are respectively a first capacitor C1 and a second capacitor C2, the first capacitor C1 is connected with the first switch module and the level conversion module, and the second capacitor C2 is connected with the second switch module.
8. The PWM-signal-based bidirectional communication interface apparatus according to claim 1, characterized by: 9. The PWM-signal-based bidirectional communication interface apparatus according to claim 1, wherein: