A daisy chain communication timeout reset system for automotive electronic devices

Abstract

The application provides a kind of automobile electronic equipment and daisy chain communication timeout reset system, which includes microcontroller, daisy chain communication module, timeout detection module and reset module, timeout detection module is arranged between daisy chain communication module and reset module, daisy chain communication module is connected with the data receiving end of microcontroller, and reset module is connected with the reset connection end of microcontroller.The daisy chain communication timeout reset system detects timeout output high level through timeout detection module, so that the reset connection end of microcontroller connected with reset module is low level, and the microcontroller is reset, which solves the problem that the existing daisy chain communication timeout applied to automobile electronic products will cause the microcontroller to crash, and the microcontroller cannot recover to normal work.The daisy chain communication timeout reset system is composed of microcontroller, daisy chain communication module, timeout detection module and reset module composed of discrete electronic components, which is low in cost and simple in software and hardware architecture.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile electronics, and particularly relates to an automobile electronic device and a timeout reset system for daisy chain communication. BACKGROUND

[0002] As the competition in the automobile market is becoming increasingly fierce, it is particularly important for automobile electronic products to reduce costs, and many measures for reducing costs by improving design have appeared. One of the measures is to use daisy chain technology. For daisy chain communication, the technology of differential signal communication and the conversion of differential signals into UART protocol and microcontroller communication connection are used, but the timeout of the daisy chain communication will cause the microcontroller to crash. SUMMARY

[0003] One embodiment of the application provides an automobile electronic device and a timeout reset system for daisy chain communication to solve the problem that the timeout of the daisy chain communication applied to the automobile electronic product will cause the microcontroller to crash and the microcontroller cannot recover to normal work.

[0004] In a first aspect, one embodiment of the application provides a timeout reset system for daisy chain communication, which comprises a microcontroller, a daisy chain communication module, a timeout detection module and a reset module, the timeout detection module is arranged between the daisy chain communication module and the reset module, the daisy chain communication module is connected with a data receiving end of the microcontroller, and the reset module is connected with a reset connection end of the microcontroller.

[0005] Optionally, the reset module comprises an eleventh resistor, a second switch tube and a twelfth resistor, a first end of the eleventh resistor is connected with an output end of the timeout detection module, a second end of the eleventh resistor is connected with a first end of the second switch tube, a second end of the second switch tube is respectively connected with the reset connection end and a first end of the twelfth resistor, a second end of the twelfth resistor is connected with a direct current power supply end, and a third end of the second switch tube is grounded.

[0006] Optionally, the daisy chain communication module comprises a first resistor, a second resistor and a first switch tube, a second end of the first switch tube is connected with an input end of the timeout detection module, a first end of the first switch tube is connected with a second end of the second resistor, a first end of the second resistor is respectively connected with the data receiving end and a second end of the first resistor, and a first end of the first resistor is connected with the direct current power supply end.

[0007] Optionally, the timeout detection module comprises a charge-discharge sub-module, a pre-stage amplification element and a post-stage amplification element, an input end of the charge-discharge sub-module is connected with an output end of the daisy chain communication module, an output end of the charge-discharge sub-module is connected with a same-direction input end of the pre-stage amplification element, an output end of the pre-stage amplification element is connected with a same-direction input end of the post-stage amplification element, and an output end of the post-stage amplification element is connected with the reset module.

[0008] Optionally, the charge-discharge sub-module comprises a third resistor, a fourth resistor and a first capacitor, a first end of the third resistor is connected with the output end of the daisy chain communication module, a second end of the third resistor is connected with a second end of the fourth resistor, a second end of the first capacitor and the same-direction input end of the pre-stage amplification element respectively, a first end of the fourth resistor is connected with a direct current power supply end, and a first end of the first capacitor is grounded.

[0009] Optionally, a sixth resistor for negative feedback of the pre-stage amplification element is connected in parallel between an opposite-direction input end of the pre-stage amplification element and the output end of the pre-stage amplification element, and a tenth resistor for positive feedback of the post-stage amplification element is connected in parallel between the same-direction input end of the post-stage amplification element and the output end of the post-stage amplification element.

[0010] Optionally, an eighth resistor and a ninth resistor for setting a voltage reference value are connected with an opposite-direction input end of the post-stage amplification element, the eighth resistor is further connected with the direct current power supply end, and the ninth resistor is further grounded.

[0011] Optionally, a fifth resistor for isolation is connected in series between the output end of the charge-discharge sub-module and the same-direction input end of the pre-stage amplification element, and a seventh resistor for isolation is connected in series between the output end of the pre-stage amplification element and the same-direction input end of the post-stage amplification element.

[0012] Optionally, the microcontroller comprises a single-chip microcomputer or a micro control unit.

[0013] In a second aspect, an embodiment of the present application provides an automotive electronic device comprising the daisy chain communication timeout reset system.

[0014] One embodiment of the present application provides a daisy chain communication timeout reset system, comprising a microcontroller, a daisy chain communication module, a timeout detection module and a reset module, the timeout detection module is arranged between the daisy chain communication module and the reset module, the daisy chain communication module is connected with a data receiving end of the microcontroller, and the reset module is connected with a reset connection end of the microcontroller. The daisy chain communication timeout reset system detects timeout output high level through the timeout detection module, so that the reset module outputs low level to the reset connection end of the microcontroller, and the microcontroller is reset, thereby solving the problem that the timeout of the daisy chain communication applied to the automobile electronic product causes the microcontroller to crash and the microcontroller cannot recover to normal work.

[0015] The daisy chain communication timeout reset system is composed of the microcontroller, the daisy chain communication module, the timeout detection module and the reset module formed by discrete electronic components, and has low cost and simple hardware and software architecture. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] In order to more completely understand the present application and its beneficial effects, the following will be described with reference to the drawings. In the following description, the same reference numerals represent the same parts.

[0018] Figure 1 The frame diagram of the daisy chain communication timeout reset system provided by one embodiment of the present application.

[0019] Figure 2 The circuit diagram of the daisy chain communication timeout reset system provided by one embodiment of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in one embodiment of the present application will be described clearly and completely with reference to the drawings in one embodiment of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0021] One embodiment of this application provides a timeout reset system for automotive electronic devices and daisy-chain communication, to solve the problem that timeouts in existing daisy-chain communication applications for automotive electronic products cause microcontrollers to crash and fail to restore normal operation. This timeout reset system for automotive electronic devices and daisy-chain communication can be applied to various automotive electronic products that require communication connections, such as in-vehicle navigation systems, dashcams, and cameras.

[0022] Example 1:

[0023] One embodiment of this application provides a daisy-chain communication timeout reset system, which is exemplary. Please refer to [link to example]. Figure 1 , Figure 1 A schematic diagram of the framework of a timeout reset system for daisy-chain communication provided in one embodiment of this application.

[0024] like Figure 1 As shown, this application provides a daisy-chain communication timeout reset system, including a microcontroller MCU, a daisy-chain communication module 10, a timeout detection module 20, and a reset module 30. The timeout detection module 20 is disposed between the daisy-chain communication module 10 and the reset module 20. The daisy-chain communication module 10 is connected to the data receiving terminal DAISY_RXD of the microcontroller MCU, and the reset module 30 is connected to the reset connection terminal DAISY_RESET of the microcontroller MCU.

[0025] Furthermore, the microcontroller (MCU) can be a single-chip microcomputer or a microprocessor unit. The MCU is used to control the reset module 30 based on the timeout detection module 20's detection of timeout, causing the reset module 30 to output a high or low level to the reset connection terminal DAISY_RESET to determine whether the MCU should be reset. This daisy-chain communication timeout reset system, through the MCU's data receiving terminal DAISY_RXD and the reset connection terminal DAISY_RESET, has low resource requirements for the MCU. In this embodiment, the reset module 30 outputs a high level to the reset connection terminal DAISY_RESET to release the MCU; the reset module 30 outputs a low level to the reset connection terminal DAISY_RESET to reset the MCU.

[0026] One embodiment of this application provides a daisy-chain communication timeout reset system that detects timeouts by a timeout detection module and outputs a high level, causing the reset module to output a low level to the reset connection terminal of the microcontroller, thus resetting the microcontroller. This solves the problem that existing daisy-chain communication timeouts in automotive electronic products can cause the microcontroller to crash and fail to restore normal operation.

[0027] Furthermore, the daisy-chain communication timeout reset system uses a microcontroller composed of discrete electronic components, a daisy-chain communication module, a timeout detection module, and a reset module, resulting in low cost and a simple hardware and software architecture.

[0028] Figure 2 A circuit diagram of a timeout reset system for daisy-chain communication provided in one embodiment of this application.

[0029] like Figure 2 As shown, in one embodiment of the present invention, the reset module 30 includes an eleventh resistor R11, a second switch Q2, and a twelfth resistor R12. The first end of the eleventh resistor R11 is connected to the output terminal of the timeout detection module 20, the second end of the eleventh resistor R11 is connected to the first end of the second switch Q2, the second end of the second switch Q2 is connected to the reset connection terminal DAISY_RESET and the first end of the twelfth resistor R12, the second end of the twelfth resistor R12 is connected to the DC power supply terminal VDD, and the third end of the second switch Q2 is grounded.

[0030] Furthermore, the DC power supply terminal VDD is used to connect to a 5V DC power supply. The second switching transistor Q2 can be selected as a transistor, with its base serving as the first terminal, its emitter as the third terminal, and its collector as the second terminal. In this embodiment, the eleventh resistor R11 is used as the base bias resistor for the second switching transistor Q2. The twelfth resistor R12 is used as the collector pull-up resistor for the second switching transistor Q2.

[0031] like Figure 2 As shown, in one embodiment of the present invention, the daisy-chain communication module 10 includes a first resistor R1, a second resistor R2, and a first switch Q1. The second end of the first switch Q1 is connected to the input terminal of the timeout detection module 20, the first end of the first switch Q1 is connected to the second end of the second resistor R2, the first end of the second resistor R2 is connected to the data receiving terminal DAISY_RXD and the second end of the first resistor R1, and the first end of the first resistor R1 is connected to the DC power supply terminal VDD.

[0032] Furthermore, the first switching transistor Q1 can be selected as an NPN transistor. The base of the transistor serves as the first terminal of the first switching transistor Q1, the emitter serves as the third terminal of the first switching transistor Q1, and the collector serves as the second terminal of the first switching transistor Q1. In other embodiments, the first switching transistor Q1 and the second switching transistor Q2 can also be selected from other IGBT transistors with the same function. In this embodiment, such as... Figure 2As shown, the first resistor R1 is used as a pull-up resistor for the data receiving terminal DAISY_RXD. The second resistor R2 is used as the base bias resistor for the first switching transistor Q1. The microcontroller (MCU) controls the operating state (on or off) of the first switching transistor Q1 through the second resistor R2.

[0033] like Figure 2 As shown, in one embodiment of the invention, the timeout detection module 20 includes a charge / discharge electronic module, a pre-amplifier U1, and a post-amplifier U2. The input terminal of the charge / discharge electronic module is connected to the output terminal of the daisy-chain communication module 10, the output terminal of the charge / discharge electronic module is connected to the non-inverting input terminal 2 of the pre-amplifier U1, the output terminal 7 of the pre-amplifier U1 is connected to the non-inverting input terminal 3 of the post-amplifier U2, and the output terminal 1 of the post-amplifier U2 is connected to the reset module 30. The charge / discharge electronic module includes a third resistor R3, a fourth resistor R4, and a first capacitor C1. The first end of the third resistor R3 is connected to the output terminal of the daisy-chain communication module 10, the second end of the third resistor R3 is connected to the second end of the fourth resistor R4, the second end of the first capacitor C1, and the non-inverting input terminal 5 of the pre-amplifier U1, the first end of the fourth resistor R4 is connected to the DC power supply terminal VDD, and the first end of the first capacitor C1 is grounded. A sixth resistor R6 for negative feedback of preamplifier U1 is connected in parallel between the inverting input terminal 6 and the output terminal 7 of preamplifier U1. A tenth resistor R10 for positive feedback of amplifier U2 is connected in parallel between the non-inverting input terminal 3 and the output terminal 1 of amplifier U2. An eighth resistor R8 and a ninth resistor R9 for setting the voltage reference value are connected to the inverting input terminal 2 of amplifier U2. The eighth resistor R8 is also connected to the DC power supply terminal VDD, and the ninth resistor R9 is grounded. A fifth resistor R5 for isolation is connected in series between the output terminal of the charge / discharge module and the non-inverting input terminal 5 of preamplifier U1; a seventh resistor R7 for isolation is connected in series between the output terminal 7 of preamplifier U1 and the non-inverting input terminal 3 of amplifier U2.

[0034] Furthermore, both the preamplifier U1 and the post-amplifier U2 can be selected as amplifiers. In this embodiment, the preamplifier U1 and the post-amplifier U2 can be a two-stage amplifier circuit composed of a dual-channel amplifier. The eighth resistor R8 and the ninth resistor R9 are connected in series to divide the voltage and set the voltage reference value of the post-amplifier U2. This daisy-chain communication timeout reset system uses a small number of resistors, capacitors, switching transistors, and amplifying components to form the timeout reset system circuit through the daisy-chain communication module, timeout detection module, and reset module, resulting in low cost. Moreover, by setting the charge and discharge time constant through the charge and discharge electronic module, the timeout time can be set to reset the microcontroller as needed.

[0035] In the embodiment of the application, the working principle of the daisy chain communication timeout reset system is that the daisy chain communication module 10 inputs high and low level signals to the microcontroller MCU at the data receiving end DAISY_RXD; when the data receiving end DAISY_RXD is at low level 0, the first switch tube Q1 is in the cutoff state, and the 5V voltage input by the DC power supply end VDD charges the first capacitor C1 through the fourth resistor R4; when the data receiving end DAISY_RXD is at high level 1, the first switch tube Q1 is in the saturation state, and the 5V input by the DC power supply end VDD discharges the first capacitor C1 through the third resistor R3, the first switch tube Q1 and the ground. The voltage V_C1 of the first capacitor C1 of the charging and discharging module changes with the charging and discharging time; the front-stage amplifying element U1 forms a voltage follower, and transmits the voltage V_C1 between the two ends of the first capacitor C1 to the same direction input end 3 of the rear-stage amplifying element U2, the eighth resistor R8 and the ninth resistor R9 are connected in series to set the voltage reference value V_REF input to the reverse input end 2 of the rear-stage amplifying element U2, the rear-stage amplifying element U2 is in positive feedback, and the voltage between the same direction input end 3 and the reverse input end 2 of the rear-stage amplifying element U2 is compared, that is, the voltage V_C1 of the first capacitor C1 is compared with the voltage reference value V_REF. If the voltage V_C1 of the first capacitor C1 is greater than the voltage reference value V_REF, the output end 2 of the rear-stage amplifying element U2 outputs high level; if the voltage V_C1 of the first capacitor C1 is less than the voltage reference value V_REF, the output end 2 of the rear-stage amplifying element U2 outputs low level. The output end of the rear-stage amplifying element U2 is connected to the reset module 30, the output end of the rear-stage amplifying element U2 outputs high level, the second switch tube Q2 is in the saturation open state, the input reset connection end DAISY_RESET is at low level, and the microcontroller MCU is reset. The output end of the rear-stage amplifying element U2 outputs low level, the second switch tube Q2 is in the cutoff state, the input reset connection end DAISY_RESET is at high level, and the microcontroller MCU is released.

[0036] Further, the daisy chain communication timeout reset system resets the microcontroller MCU at the data receiving end DAISY_RXD after about 150 ms. As an example, the voltage V of the DC power supply end VDD is +5V, the resistance of the first resistor R1 is 4.7K, the resistance of the second resistor R2 is 10K, and the first switch tube Q1 is a BC846B triode. When the data receiving end DAISY_RXD of the microcontroller MCU is at a high level, the first switch tube Q1 enters the saturation region and is in a conducting state. When the data receiving end DAISY_RXD of the microcontroller MCU is at a low level, the first switch tube Q1 enters the cut-off region and is in a non-conducting state. The resistance of the third resistor R3 is 10K to facilitate fast discharge of the first capacitor C1, and the resistance of the fourth resistor R4 is 470K to facilitate slow charging of the first capacitor C1. The capacitance of the first capacitor C1 is 330nF. According to the RC charging and discharging principle of the charging and discharging module: when the time constant t = 1*R4C1, the voltage V_C1 of the first capacitor C1 is 0.63*V; when t = 2*R4C1, the voltage V_C1 of the first capacitor C1 is 0.86*V. When τ1 is the R4C1 charging time constant, which is about 155ms, and τ2 is the R3C1 discharging time constant, which is about 3.3ms, the discharging time constant is much lower than the charging time constant, i.e. the voltage V_C1 of the first capacitor C1 charges slowly and discharges quickly. The negative feedback of the pre-stage amplifying element U1 constitutes a voltage follower, and the voltage V_C1 of the first capacitor C1 is transmitted to the same direction input end 3 of the post-stage discharging element U2. The resistance of the eighth resistor R8 is 620K, the resistance of the ninth resistor R9 is 1M, and the voltage reference value V_REF is about 3.1V, which is input to the reverse input end 2 of the post-stage amplifying element U2. The charging voltage is equal to 5V, and the voltage of the first capacitor C1 is equal to 0.63*5V = 3.15V after about one time constant τ. The positive feedback of the post-stage amplifying element U2 constitutes an open loop state. If the voltage V_C1 of the first capacitor C1 is greater than the preset voltage reference value V_REF, the output end 1 of the post-stage amplifying element U2 outputs a high level, and vice versa. The output end 1 of the post-stage amplifying element U2 is connected to the reset module 30, the resistance of the eleventh resistor R11 is 10K, the resistance of the twelfth resistor R12 is 10K, and the second switch tube Q2 is preferably a BC846B triode. When the output end 1 of the post-stage amplifying element U2 outputs a high level, the second switch tube Q2 is in a working state, the output to the reset connection end DAISY_RESET is a low level, and the microcontroller MCU is reset. When the output end 1 of the post-stage amplifying element U2 outputs a low level, the output to the reset connection end DAISY_RESET is a high level, and the microcontroller MCU is released.

[0037] Embodiment two:

[0038] The application provides an automobile electronic device, comprising the daisy chain communication timeout reset system.

[0039] Further, the daisy chain communication timeout reset system is described in the first embodiment, which is not repeated in the following embodiments. Figure 2 As shown in the figure, the automobile electronic device resets the timeout microcontroller through the daisy chain communication timeout reset system. Specifically, the daisy chain communication module 10 inputs high and low level signals to the microcontroller MCU through the data receiving end DAISY_RXD; when the data receiving end DAISY_RXD is low level 0, the first switch tube Q1 is in the off state, and the 5V voltage input by the DC power supply end VDD charges the first capacitor C1 through the fourth resistor R4; when the data receiving end DAISY_RXD is high level 1, the first switch tube Q1 is in the saturation state, and the 5V input by the DC power supply end VDD discharges the first capacitor C1 through the third resistor R3, the first switch tube Q1 and the ground. The voltage V_C1 of the first capacitor C1 of the charging and discharging module changes with the charging and discharging time; the front-stage amplifying element U1 forms a voltage follower, which transmits the voltage V_C1 between the two ends of the first capacitor C1 to the same direction input end 3 of the rear-stage amplifying element U2, the eighth resistor R8 and the ninth resistor R9 are connected in series to set the voltage reference value V_REF input to the reverse input end 2 of the rear-stage amplifying element U2, the rear-stage amplifying element U2 is in positive feedback, and the voltage between the same direction input end 3 and the reverse input end 2 of the rear-stage amplifying element U2 is compared, that is, the voltage V_C1 of the first capacitor C1 is compared with the voltage reference value V_REF. If the voltage V_C1 of the first capacitor C1 is greater than the voltage reference value V_REF, the output end 2 of the rear-stage amplifying element U2 outputs high level; if the voltage V_C1 of the first capacitor C1 is less than the voltage reference value V_REF, the output end 2 of the rear-stage amplifying element U2 outputs low level. The output end of the rear-stage amplifying element U2 is connected to the reset module 30, the output end of the rear-stage amplifying element U2 outputs high level, the second switch tube Q2 is in the saturation open state, the input reset connection end DAISY_RESET is low level, and the microcontroller MCU is reset. The output end of the rear-stage amplifying element U2 outputs low level, the second switch tube Q2 is in the off state, the input reset connection end DAISY_RESET is high level, and the microcontroller MCU is released.

[0040] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0041] In the description of the present application, the terms "first", "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features.

[0042] The timeout reset system of the daisy chain communication provided by the embodiment of the present application is described in detail above, and the principles and implementation manners of the present application are described by applying specific examples in this paper. The above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will be changed, and in view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A timeout reset system for daisy-chain communication, characterized in that, It includes a microcontroller, a daisy-chain communication module, a timeout detection module, and a reset module. The timeout detection module is located between the daisy-chain communication module and the reset module. The daisy-chain communication module is connected to the data receiving end of the microcontroller, and the reset module is connected to the reset connection end of the microcontroller. The reset module includes an eleventh resistor, a second switching transistor, and a twelfth resistor. The first end of the eleventh resistor is connected to the output terminal of the timeout detection module, the second end of the eleventh resistor is connected to the first end of the second switching transistor, the second end of the second switching transistor is connected to the reset connection terminal and the first end of the twelfth resistor, the second end of the twelfth resistor is connected to the DC power supply terminal, and the third end of the second switching transistor is grounded. The daisy-chain communication module includes a first resistor, a second resistor, and a first switch. The second end of the first switch is connected to the input end of the timeout detection module. The first end of the first switch is connected to the second end of the second resistor. The first end of the second resistor is connected to both the data receiving end and the second end of the first resistor. The first end of the first resistor is connected to the DC power supply end. The timeout detection module includes a charge / discharge electronic module, a preamplifier, and a postamplifier. The input terminal of the charge / discharge electronic module is connected to the output terminal of the daisy-chain communication module. The output terminal of the charge / discharge electronic module is connected to the non-inverting input terminal of the preamplifier. The output terminal of the preamplifier is connected to the non-inverting input terminal of the postamplifier. The output terminal of the postamplifier is connected to the reset module. The charge / discharge electronic module includes a third resistor, a fourth resistor, and a first capacitor. The first end of the third resistor is connected to the output end of the daisy-chain communication module. The second end of the third resistor is connected to the second end of the fourth resistor, the second end of the first capacitor, and the non-inverting input end of the preamplifier. The first end of the fourth resistor is connected to the DC power supply. The first end of the first capacitor is grounded.

2. The timeout reset system for daisy-chain communication according to claim 1, characterized in that, A sixth resistor for negative feedback of the preamplifier is connected in parallel between the inverting input terminal and the output terminal of the preamplifier, and a tenth resistor for positive feedback of the postamplifier is connected in parallel between the non-inverting input terminal and the output terminal of the postamplifier.

3. The timeout reset system for daisy-chain communication according to claim 1, characterized in that, The inverting input terminal of the subsequent amplifier is connected to an eighth resistor and a ninth resistor for setting a voltage reference value. The eighth resistor is also connected to a DC power supply terminal, and the ninth resistor is also grounded.

4. The timeout reset system for daisy-chain communication according to claim 1, characterized in that, A fifth resistor for isolation is connected in series between the output terminal of the charge / discharge electronic module and the non-inverting input terminal of the preamplifier; a seventh resistor for isolation is connected in series between the output terminal of the preamplifier and the non-inverting input terminal of the postamplifier.

5. The timeout reset system for daisy-chain communication according to claim 1, characterized in that, The microcontroller includes a single-chip microcomputer or a microprocessor unit.

6. An automotive electronic device, characterized in that, Including the timeout reset system for daisy-chain communication as described in any one of claims 1-5.

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