CAN data transceiver compatible with high speed and low speed

Abstract

The utility model relates to the technical field of automobile bus communication, and provides a CAN (Controller Area Network) data transceiver compatible with high speed and low speed, aiming at the functional requirements of a high-speed / low-speed CAN, a high-speed CAN module and a low-speed CAN module are simultaneously connected into an automobile body CAN interface module, and a first switch module and a second switch module are arranged to carry out independent power supply control. And the master control module realizes state switching of the high-speed CAN module / the low-speed CAN module by controlling on and off of the first switch module / the second switch module, so that transceiving path switching between the high-speed CAN module and the low-speed CAN module is realized. Hardware is fully compatible, needed modules are switched through software configuration to achieve the purpose, only one CAN channel of an MCU master control kernel is adopted, the requirements of high-speed / low-speed CAN protocol specifications are met, the high-speed CAN or the low-speed CAN can be switched to operate independently through the software configuration, equipment of different CAN standards is supported, and system compatibility and expansibility are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of CAN data transceiver devices of compatible high-low speed in the automobile bus communication technical field, in particular to a kind of CAN data transceiver devices of compatible high-low speed. BACKGROUND

[0002] At present, vehicle-mounted overseas OEM customers hope that a host computer is compatible with multiple vehicle models, to simplify product development process and reduce model certification, management cost. Because CAN_H and CAN_L signals are important standard interface lines of vehicle body and cannot be added with electronic switch, traditional imported brand MCU master control chip only has 2 CAN function solidification special ports (2 groups of high / low speed CAN need 4 special ports and cannot be satisfied), and the protocol specification and signal voltage of the two chips are different. For example:

[0003] High-speed CAN transmission rate range is 125kbit / s~1Mbit / s, and the level on CAN-H and CAN-L is 2.5V when transmitting recessive state bit, and the level on CAN-H is 3.5V and the level on CAN-L is 1.5V when transmitting dominant state bit.

[0004] Low-speed CAN transmission rate range is 5~125kbit / s, and the level on CAN-H is 0V and the level on CAN-L is 5V when transmitting recessive state bit, and the level on CAN-H is 3.6V and the level on CAN-L is 1.4V when transmitting dominant state bit; the communication protocol is completely incompatible.

[0005] Therefore, if the two are simply used in physical layer line superposition and parallel connection, signal level disorder will be caused, resulting in abnormal CAN network of whole vehicle. In view of the current development and application of domestic MCU, the port is sufficient (switching channel is flexible through software configuration). High-speed / low-speed CAN is an important standard interface of vehicle-mounted system, and how to realize interface compatibility has significant practical significance for overseas OEM customers to reduce model certification and test cost. UTILITY MODEL CONTENTS

[0006] The utility model provides a kind of CAN data transceiver devices of compatible high-low speed, solve the technical problem that existing vehicle-mounted host computer cannot be compatible with high-speed / low-speed CAN function, user experience is poor.

[0007] To solve the above technical problems, the utility model provides a kind of CAN data transceiver devices of compatible high-low speed, including vehicle body CAN interface module, high-speed CAN module, low-speed CAN module, power supply control module and master control module, the master control module is connected with high-speed CAN module, low-speed CAN module, power supply control module, the vehicle body CAN interface module is connected with high-speed CAN module, low-speed CAN module;

[0008] The power supply control module comprises a first switch module and a second switch module; a control end of the first switch module is connected with the master control module, an input end is connected with a power supply, and an output end is connected with the high-speed CAN module; a control end of the second switch module is connected with the master control module, an input end is connected with the power supply, and an output end is connected with the low-speed CAN module.

[0009] In a further embodiment, the first switch module comprises a first switch unit, and the first switch unit comprises a first switch tube Q1, a second switch tube Q2, resistors R1-R4 and a capacitor C1.

[0010] The control end of the first switch tube Q1 is connected with the master control module through a resistor R1 and grounded through a resistor R2, a first end is connected with the control end of the second switch tube Q2 through a resistor R3, and a second end is grounded.

[0011] The first end of the second switch tube Q2 is connected with a first power supply, the second end is connected with a VCC pin of the high-speed CAN module, both ends of a resistor R4 are connected with the control end and the first end of the second switch tube Q2 respectively, and a capacitor C1 is connected with the resistor R4 in parallel.

[0012] In a further embodiment, the first switch module further comprises a second switch unit, and the second switch unit comprises a third switch tube Q3, a fourth switch tube Q4, resistors R5-R8 and a capacitor C2.

[0013] The control end of the third switch tube Q3 is connected with the master control module through a resistor R5 and grounded through a resistor R6, a first end is connected with the control end of the fourth switch tube Q4 through a resistor R7, and a second end is grounded.

[0014] The first end of the fourth switch tube Q4 is connected with a second power supply, the second end is connected with a VIO pin of the high-speed CAN module, both ends of a resistor R8 are connected with the control end and the first end of the fourth switch tube Q4 respectively, and a capacitor C2 is connected with the resistor R8 in parallel.

[0015] In a further embodiment, the second switch module comprises a third switch unit, and the third switch unit comprises a fifth switch tube Q5, a sixth switch tube Q6, resistors R9-R12 and a capacitor C3.

[0016] The control end of the fifth switch tube Q5 is connected with the master control module through a resistor R9 and grounded through a resistor R10, a first end is connected with the control end of the second switch tube Q2 through a resistor R11, and a second end is grounded.

[0017] The first end of the sixth switch tube Q6 is connected with a first power supply, and the second end is connected with a VCC pin of the low-speed CAN module; the two ends of the resistor R12 are connected with the control end and the first end of the sixth switch tube Q6 respectively; and the capacitor C3 is connected with the resistor R12 in parallel.

[0018] In a further embodiment, the second switch module further comprises a fourth switch unit, the fourth switch unit comprising a seventh switch tube Q7, an eighth switch tube Q8 and resistors R13-R16.

[0019] The control end of the seventh switch tube Q7 is connected with the master control module through the resistor R13 and grounded through the resistor R14; the first end is connected with the control end of the eighth switch tube Q8 through the resistor R15; and the second end is grounded.

[0020] The first end of the eighth switch tube Q8 is connected with a third power supply, and the second end is connected with a BAT pin of the low-speed CAN module; the two ends of the resistor R16 are connected with the control end and the first end of the eighth switch tube Q8 respectively.

[0021] In a further embodiment, the master control module comprises a storage module, a programmable data channel switching module, a CAN controller and a kernel processing module connected in sequence; the programmable data channel switching module is connected with the high-speed CAN module and the low-speed CAN module; and the kernel processing module is connected with the first switch module and the second switch module through a GPIO port.

[0022] In a further embodiment, the vehicle body CAN interface module comprises two bidirectional TVS tubes, one end of each of the bidirectional TVS tubes being connected to a vehicle body CAN signal input end and the other end being connected to the ground.

[0023] In a further embodiment, the first switch tube Q1 is an NPN triode, and the third switch tube Q3 is an NPN triode; the second switch tube Q2 is a P-channel MOS tube, and the fourth switch tube Q4 is a P-channel MOS tube.

[0024] In a further embodiment, the fifth switch tube Q5 is an NPN triode, the sixth switch tube Q6 is a P-channel MOS tube, the seventh switch tube Q7 is an NPN triode, and the eighth switch tube Q8 is a PNP triode.

[0025] The utility model discloses the beneficial effect is as follows:

[0026] (1) This scheme is aimed at the functional requirements of high-speed / low-speed CAN, the high-speed CAN module and the low-speed CAN module are simultaneously connected to the vehicle body CAN interface module, and the first switch module and the second switch module are arranged for independent power supply control, and then the master control module controls the first switch module / second switch module to realize the state switching of the high-speed CAN module / low-speed CAN module, so as to realize the switching of the receiving and transmitting paths between the high-speed CAN module and the low-speed CAN module. Hardware is fully compatible, and the required module is switched by software configuration to achieve the purpose, only one CAN channel of the MCU master control kernel is adopted, the requirements of high-speed / low-speed two CAN protocol specifications are met, the high-speed or low-speed CAN can be independently operated by software configuration, different CAN standard devices are supported, and the system compatibility and expansibility are improved.

[0027] (2) The first switch module and the second switch module composed of switch tubes are arranged, flexible switching is realized through power supply control, the fixed connection of the vehicle body CAN interface module with the high-speed CAN module and the low-speed CAN module is adapted, the high-speed or low-speed CAN is dynamically selected, different communication rates and distance requirements are adapted, and diversified requirements are met. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a frame diagram of a CAN data receiving and transmitting device compatible with high and low speeds provided by an embodiment of the present application;

[0029] Figure 2 is a partial hardware circuit diagram provided by an embodiment of the present application;

[0030] Figure 3 is a partial hardware circuit diagram provided by an embodiment of the present application;

[0031] Figure 4 is a partial hardware circuit diagram provided by an embodiment of the present application;

[0032] Figure 5 is a partial hardware circuit diagram provided by an embodiment of the present application;

[0033] Among them: vehicle body CAN interface module 1, high-speed CAN module 2, low-speed CAN module 3, first switch module 4, second switch module 5, programmable data channel switching module 6, CAN controller 7, kernel processing module 8; high-speed CAN chip U1, low-speed CAN chip U2. DETAILED DESCRIPTION

[0034] The embodiments of the present application are specifically illustrated below with reference to the drawings, and the embodiments are only for the purpose of illustration and cannot be understood as limiting the present application, including the drawings for reference and illustration only, and do not constitute a limitation on the patent protection scope of the present application, because many changes can be made to the present application without departing from the spirit and scope of the present application.

[0035] The CAN data transceiving device compatible with high and low speeds provided by the embodiment of the present application, as shown in the figure, in the embodiment, includes a vehicle body CAN interface module 1, a high-speed CAN module 2, a low-speed CAN module 3, a power supply control module and a main control module, the main control module is connected with the high-speed CAN module 2, the low-speed CAN module 3 and the power supply control module, the vehicle body CAN interface module 1 is connected with the high-speed CAN module 2 and the low-speed CAN module 3. Figures 1-5

[0036] The power supply control module includes a first switch module 4 and a second switch module 5; the control end of the first switch module 4 is connected with the high-speed CAN module 2, the input end is connected with a power supply, and the output end is connected with the main control module; the control end of the second switch module 5 is connected with the main control module, the input end is connected with the power supply, and the output end is connected with the low-speed CAN module 3.

[0037] Among them, the high-speed CAN module 2 includes a high-speed CAN chip U1 and a peripheral circuit (such as a terminal resistor), and the low-speed CAN module 3 includes a low-speed CAN chip U2 and a peripheral circuit.

[0038] The power supply is provided based on the power demand of the circuit, and includes:

[0039] The first power supply supports a 5V power supply;

[0040] The second power supply supports a 3.3V power supply;

[0041] The third power supply is a B+ main power supply, which is powered by a vehicle-mounted storage battery.

[0042] In the embodiment, the first switch module 4 includes a first switch unit, and the first switch unit includes a first switch tube Q1, a second switch tube Q2, resistors R1-R4 and a capacitor C1.

[0043] The control end of the first switch tube Q1 is connected with the main control module through a resistor R1 and grounded through a resistor R2, the first end is connected with the control end of the second switch tube Q2 through a resistor R3, and the second end is grounded.

[0044] ​The first end of the second switch tube Q2 is connected with a first power supply (5V power supply), the second end is connected with the VCC pin of the high-speed CAN module 2, the two ends of the resistor R4 are connected with the control end and the first end of the second switch tube Q2 respectively, and the capacitor C1 is connected with the resistor R4 in parallel.

[0045] In the embodiment, the first switch module 4 further comprises a second switch unit, the second switch unit comprising a third switch tube Q3, a fourth switch tube Q4, resistors R5-R8 and a capacitor C2.

[0046] The control end of the third switch tube Q3 is connected with the master control module through the resistor R5 and is further grounded through the resistor R6, the first end is connected with the control end of the fourth switch tube Q4 through the resistor R7, and the second end is grounded.

[0047] The first end of the fourth switch tube Q4 is connected with a second power supply (3.3V power supply), the second end is connected with the VIO pin of the high-speed CAN module 2, the two ends of the resistor R8 are connected with the control end and the first end of the fourth switch tube Q4 respectively, and the capacitor C2 is connected with the resistor R8 in parallel.

[0048] In the embodiment, the second switch module 5 comprises a third switch unit for controlling the power supply of the low-speed CAN chip U2, the third switch unit comprising a fifth switch tube Q5, a sixth switch tube Q6, resistors R9-R12 and a capacitor C3.

[0049] The control end of the fifth switch tube Q5 is connected with the master control module through the resistor R9 and is further grounded through the resistor R10, the first end is connected with the control end of the sixth switch tube Q6 through the resistor R11, and the second end is grounded.

[0050] The first end of the sixth switch tube Q6 is connected with the first power supply, the second end is connected with the VCC pin of the low-speed CAN module 3, the two ends of the resistor R12 are connected with the control end and the first end of the sixth switch tube Q6 respectively, and the capacitor C3 is connected with the resistor R12 in parallel.

[0051] In the embodiment, the second switch module 5 further comprises a fourth switch unit for controlling the B+ power supply of the low-speed CAN module 3, the fourth switch unit comprising a seventh switch tube Q7, an eighth switch tube Q8 and resistors R13-R16.

[0052] The control end of the seventh switch tube Q7 is connected with the master control module through the resistor R13 and is further grounded through the resistor R14, the first end is connected with the control end of the eighth switch tube Q8 through the resistor R15, and the second end is grounded.

[0053] The first end of the eighth switch tube Q8 is connected with a third power supply (main power supply, vehicle-mounted battery power supply), and the second end is connected with the BAT pin of the low-speed CAN module 3, and the two ends of the resistor R16 are connected with the control end and the first end of the eighth switch tube Q8 respectively.

[0054] In the embodiment, the main control module comprises a storage module, a programmable data channel switching module 6, a CAN controller 7 and a kernel processing module 8 connected in sequence, the programmable data channel switching module 6 is connected with the high-speed CAN module 2 and the low-speed CAN module 3, and the kernel processing module 8 is connected with the first switch module 4 and the second switch module 5 through a GPIO port.

[0055] The storage module is used for storing a CAN configuration file.

[0056] The programmable data channel switching module 6 is used for switching the data sent to the CAN controller 7 to the corresponding channel according to the configuration file.

[0057] The CAN controller 7 is used for processing the received CAN data.

[0058] The kernel processing module 8 is used for configuring the level of the control end of the first switch module 4 and the second switch module 5 according to the configuration file.

[0059] Preferably, the main control module selects an MCU main control chip (for example, a small Hua HC32A4A0 series), and the kernel has two CAN controllers 7.

[0060] In the embodiment, the vehicle body CAN interface module 1 comprises two bidirectional TVS tubes, one end of each of the bidirectional TVS tubes is connected to a vehicle body CAN signal input end, and the other end is connected to the ground.

[0061] In the embodiment, the first switch tube Q1 is an NPN type triode, and the third switch tube Q3 is an NPN type triode; the second switch tube Q2 is a P-channel MOS tube, and the fourth switch tube Q4 is a P-channel MOS tube.

[0062] In the embodiment, the fifth switch tube Q5 is an NPN triode, the sixth switch tube Q6 is a P-channel MOS tube, the seventh switch tube Q7 is an NPN triode, and the eighth switch tube Q8 is a PNP triode. Taking the master control module as an MCU as an example, the working principle of the embodiment is as follows:

[0063] Step 1: Write the vehicle CAN configuration file in the storage module of the MCU.

[0064] Step 2: Restart the IVI vehicle machine, and configure the power supply GPIO ports (the first switch module 4 and the second switch module 5) of the high-speed CAN module 2 and the low-speed CAN module 3 of the MCU and the programmable data channel switching module 6 according to the CAN configuration file.

[0065] Step 3: Power switch control

[0066] (1) If it is judged that the high-speed CAN is used, the GPIO port connected with the first switch module 4 is controlled to be high level, the GPIO port connected with the second switch module 5 is controlled to be low level, and the programmable data channel switching module 6 is switched to receive the high-speed CAN signal.

[0067] When the high-speed CAN is used, the MCU controls the fifth switch tube Q5 and the seventh switch tube Q7 to make the sixth switch tube Q6 and the eighth switch tube Q8 cut off and conduct, cut off the BAT+ and VCC power supply, and simultaneously shut down the STB and EN pins, so that the low-speed CAN module 3 is in the shutdown state (note: the low-speed CAN chip U2 BAT+ power supply of the low-speed CAN module 3 must be controlled to cut off the circuit, otherwise the CAN_L will be connected to the BAT+ through the internal circuit of the chip, which will cause the high-speed CAN communication to collapse); the MCU controls the first switch tube Q1 and the third switch tube Q3 to make the second switch tube Q2 and the fourth switch tube Q4 conduct, the VCC and VIO power supply of the high-speed CAN chip U1 in the high-speed CAN module 2 are connected, and the STB and EN are synchronously turned on, so that the high-speed CAN module 2 can work normally.

[0068] (2) If it is judged that the low-speed CAN is used, the GPIO port connected with the first switch module 4 is controlled to be low level, the GPIO port connected with the second switch module 5 is controlled to be high level, and the programmable data channel switching module 6 is switched to receive the low-speed CAN signal.

[0069] When using low-speed CAN, the MCU turns off the first switch tube Q1 and the third switch tube Q3 to make the second switch tube Q2 and the fourth switch tube Q4 off, the VCC and IVO power supply of the high-speed CAN chip U1 is cut off, the STB and EN are synchronously turned off, and the high-speed CAN module 2 is in a shutdown state; the MCU turns on the fifth switch tube Q5 and the seventh switch tube Q7 to make the sixth switch tube Q6 and the eighth switch tube Q8 conductive, the BAT+ and VCC power supply are turned on, and the STB and EN pins are turned on at the same time, and the low-speed CAN can work normally.

[0070] In the fourth step, the CAN controller 7 processes the received CAN data and sends the processing result to the kernel processing module 8 to perform corresponding operations.

[0071] In the embodiment, the application scenarios of the IVI vehicle machine using the CAN transceiver device include:

[0072] For example, the application scenario one: the IVI vehicle machine is a non-terminal node (i.e., the IVI vehicle machine is an intermediate node), the high-speed CAN terminal resistance is NC (empty), and the low-speed CAN terminal resistance is 4.7K.

[0073] For example, the application scenario two: the IVI vehicle machine is a terminal node, the high-speed CAN terminal resistance is 50-65 ohms, and the low-speed CAN terminal resistance is 510 ohms; and due to the influence of the high-speed CAN terminal resistance, if the low-speed CAN is used, only single-wire working mode can be selected.

[0074] The beneficial effects of the embodiments of the utility model are as follows:

[0075] (1) The scheme is aimed at the functional requirements of high-speed / low-speed CAN, the high-speed CAN module 2 and the low-speed CAN module 3 are simultaneously connected to the vehicle body CAN interface module 1, the first switch module 4 and the second switch module 5 are arranged for independent power supply control, and then the master control module controls the first switch module 4 / second switch module 5 to realize the state switching of the high-speed CAN module 2 / low-speed CAN module 3, so as to realize the switching of the receiving and transmitting paths between the high-speed CAN module 2 and the low-speed CAN module 3. The hardware is fully compatible, the required modules are switched by software configuration to achieve the purpose, only one CAN channel of the MCU master control kernel is used, the requirements of high-speed / low-speed two CAN protocol specifications are met, the high-speed or low-speed CAN can be independently operated by software configuration, different CAN standard devices are supported, and the system compatibility and expansibility are improved.

[0076] (2) The first switch module 4 and the second switch module 5 composed of switch tubes are arranged, flexible switching is realized through power supply control, the fixed connection of the vehicle body CAN interface module 1 with the high-speed CAN module 2 and the low-speed CAN module 3 is adapted, the high-speed or low-speed CAN is dynamically selected, different communication rates and distance requirements are adapted, and diversified requirements are met.

[0077] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A CAN data transceiver compatible with both high and low speeds, characterized in that: It includes a body CAN interface module, a high-speed CAN module, a low-speed CAN module, a power supply control module, and a main control module. The main control module is connected to the high-speed CAN module, the low-speed CAN module, and the power supply control module. The body CAN interface module is connected to the high-speed CAN module and the low-speed CAN module. The power supply control module includes a first switch module and a second switch module; the control terminal of the first switch module is connected to the main control module, the input terminal is connected to the power supply, and the output terminal is connected to the high-speed CAN module; the control terminal of the second switch module is connected to the main control module, the input terminal is connected to the power supply, and the output terminal is connected to the low-speed CAN module.

2. The CAN data transceiver device compatible with both high and low speeds as described in claim 1, characterized in that: The first switching module includes a first switching unit, which includes a first switching transistor Q1, a second switching transistor Q2, resistors R1 to R4, and a capacitor C1. The control terminal of the first switch Q1 is connected to the main control module through resistor R1 and grounded through resistor R2. The first terminal is connected to the control terminal of the second switch Q2 through resistor R3, and the second terminal is grounded. The first end of the second switch Q2 is connected to the first power supply, and the second end is connected to the VCC pin of the high-speed CAN module. The two ends of the resistor R4 are connected to the control terminal and the first end of the second switch Q2, respectively. The capacitor C1 is connected in parallel with the resistor R4.

3. A CAN data transceiver compatible with both high and low speeds as described in claim 2, characterized in that: The first switching module further includes a second switching unit, which includes a third switching transistor Q3, a fourth switching transistor Q4, resistors R5 to R8, and capacitor C2. The control terminal of the third switch Q3 is connected to the main control module through resistor R5 and grounded through resistor R6. The first terminal is connected to the control terminal of the fourth switch Q4 through resistor R7, and the second terminal is grounded. The first end of the fourth switch Q4 is connected to the second power supply, and the second end is connected to the VIO pin of the high-speed CAN module. The two ends of the resistor R8 are connected to the control terminal and the first end of the fourth switch Q4, respectively. The capacitor C2 is connected in parallel with the resistor R8.

4. A CAN data transceiver compatible with both high and low speeds as described in claim 1, characterized in that: The second switching module includes a third switching unit, which includes a fifth switching transistor Q5, a sixth switching transistor Q6, resistors R9 to R12, and a capacitor C3. The control terminal of the fifth switch Q5 is connected to the main control module through resistor R9 and grounded through resistor R10. The first terminal is connected to the control terminal of the sixth switch Q6 through resistor R11, and the second terminal is grounded. The first end of the sixth switch Q6 is connected to the first power supply, and the second end is connected to the VCC pin of the low-speed CAN module. The two ends of the resistor R12 are connected to the control terminal and the first end of the sixth switch Q6, respectively. The capacitor C3 is connected in parallel with the resistor R12.

5. A CAN data transceiver compatible with both high and low speeds as described in claim 4, characterized in that: The second switching module also includes a fourth switching unit, which includes a seventh switching transistor Q7, an eighth switching transistor Q8, and resistors R13 to R16. The control terminal of the seventh switch Q7 is connected to the main control module through resistor R13 and grounded through resistor R14. The first terminal is connected to the control terminal of the eighth switch Q8 through resistor R15, and the second terminal is grounded. The first end of the eighth switch Q8 is connected to the third power supply, the second end is connected to the BAT pin of the low-speed CAN module, and the two ends of the resistor R16 are connected to the control terminal and the first end of the eighth switch Q8, respectively.

6. A CAN data transceiver compatible with both high and low speeds as described in claim 1, characterized in that: The main control module includes a storage module, a programmable data channel switching module, a CAN controller, and a kernel processing module connected in sequence. The programmable data channel switching module is connected to the high-speed CAN module and the low-speed CAN module. The kernel processing module is connected to the first switch module and the second switch module through GPIO ports.

7. A CAN data transceiver compatible with both high and low speeds as described in claim 1, characterized in that: The vehicle body CAN interface module includes two bidirectional TVS diodes, with one end of each bidirectional TVS diode connected to the vehicle body CAN signal input terminal and the other end connected to ground.

8. A CAN data transceiver compatible with both high and low speeds as described in claim 3, characterized in that: The first switch Q1 is an NPN transistor, the third switch Q3 is an NPN transistor, the second switch Q2 is a P-channel MOSFET, and the fourth switch Q4 is a P-channel MOSFET.

9. A CAN data transceiver compatible with both high and low speeds as described in claim 5, characterized in that: The fifth switch Q5 is an NPN transistor, the sixth switch Q6 is a P-channel MOSFET, the seventh switch Q7 is an NPN transistor, and the eighth switch Q8 is a PNP transistor.

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