A direct reading sonic velocity meter power supply and communication conversion circuit

Abstract

The present invention relates to a direct-reading sound velocity meter power supply and communication conversion circuit. The present invention comprises a level conversion module, the level conversion module comprises a first level conversion unit, a logic gate unit, and a second level conversion unit connected in sequence; the first level conversion unit is connected to a host computer, and is used to convert a USB signal of the host computer into a TTL signal, and the second level conversion unit is connected to a sound velocity meter, and is used to convert the TTL signal into an RS485 signal for the sound velocity meter; a control module, the control module is connected to a logic gate unit, and the logic gate unit controls the flow direction of data sent by the sound velocity meter to the host computer by changing the output level of the control module; a boost module, the boost module is respectively connected to the host computer and the sound velocity meter. The direct-reading sound velocity meter of the present invention adopts USB communication and power supply through the conversion circuit, and the mobile phone data cable used in daily life can be applied to the sound velocity meter, which reduces the cost and improves the portability of the device.

Description

Technical Field

[0001] The invention relates to the technical field of sonic velocity meters, in particular to a power supply and communication conversion circuit for a direct-reading sonic velocity meter. Background Art

[0002] As the most effective means of underwater detection, hydroacoustic signals have been widely used in various sonar devices for underwater target detection. The sound velocity meter is an underwater measuring instrument that measures the speed of sound within a certain depth range of the current water area. The most commonly used sound velocity meters are mainly divided into two types: self-contained sound velocity meters and direct-reading sound velocity meters. The direct-reading sound velocity meter is deployed through a dedicated cable, and the measurement data is sent directly to the host computer through the cable for direct reading.

[0003] Traditional direct-reading sound velocity meters require an external dedicated battery box or DC power supply, and the data measured by the sound velocity meter can only be read on the host computer through a DB9 serial port to USB cable, which increases hardware costs and is not easy to carry and use. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the problem that the traditional direct-reading sound velocity meter in the prior art needs to be powered by an external dedicated battery box or a DC power supply, and the data measured by the sound velocity meter can only be read on the host computer through a DB9 serial port to USB cable, which increases the hardware cost and is not convenient to carry and use.

[0005] In order to solve the above technical problems, the present invention provides a direct reading sonic velocity meter power supply and communication conversion circuit, comprising

[0006] A level conversion module, the level conversion module includes a first level conversion unit, a logic gate unit, and a second level conversion unit connected in sequence; the first level conversion unit is connected to a host computer and is used to convert a USB signal of the host computer into a TTL signal, and the second level conversion unit is connected to a sound velocity meter and is used to convert the TTL signal into an RS485 signal to the sound velocity meter;

[0007] A control module, wherein the control module is connected to the logic gate unit, and the control module is used to establish communication between the host computer and the conversion module, and between the conversion module and the sound velocity meter, so that the sound velocity meter sends data to the host computer. The logic gate unit changes the output level of the control module, thereby controlling the flow direction of the sound velocity meter sending data to the host computer, so that the host computer, the conversion circuit module and the sound velocity meter can correctly receive the data at their respective receiving ends;

[0008] A boost module is connected to the host computer and the sound velocity meter respectively, and is used to boost the voltage output by the host computer and then supply it to the sound velocity meter.

[0009] In one embodiment of the present invention, the boost module includes a Boost boost circuit, which includes: a boost integrated module XL6009, capacitors C14~C17, resistors R12, resistors R13, diodes, and inductors L1; the boost integrated module XL6009 includes pins 1~5, wherein pin 1 is grounded, pin 2 is a chip enable terminal, pin 3 is a power switch output, and pin 4 is an input voltage positive; pin 5 is a feedback pin; one end of capacitor C14 is connected to the input voltage, and the other end of capacitor C14 is grounded; one end of capacitor C15 is respectively connected to one end of capacitor C14 and pin 4, and capacitor C15 The other end is connected to the other end of capacitor C15 and pin 1 respectively; one end of inductor L1 is connected to one end of capacitor C15, and the other end of inductor L1 is connected to pin 3 and the positive electrode of the diode respectively, and the cathode of the diode is connected to the output voltage; one end of resistor R12 is connected to the negative electrode of the diode and the output voltage respectively, and the other end of resistor R12 is connected to pin 5 and one end of resistor R13 respectively, and the other end of resistor R13 is grounded; one end of capacitor C16 is connected to one end of resistor R12 and the output voltage respectively, and the other end of capacitor C16 is grounded; one end of capacitor C17 is connected to the output voltage, and the other end of capacitor C17 is connected to the other end of the capacitor.

[0010] In one embodiment of the present invention, the control module includes a control circuit, which includes an AT89C2051 microprocessor. The AT89C2051 microprocessor includes pins 1 to 19, pin 1 is a reset pin, high level reset; pins 2 and 3 are chip serial port transceiver pins, used to receive and send TTL data; pins 4 and 5 are crystal oscillator input and output pins, providing a clock cycle for the chip; pins 15 to 19 are 8-bit bidirectional I / O ports, used to output control signals.

[0011] In one embodiment of the present invention, the logic gate unit includes a logic gate circuit, including two 74HC08 chips and one 74HC32 chip, the transmitting end TXD1 of the host computer is respectively connected to the two 74HC08 chips, and the receiving end RXD1 of the host computer is connected to the 74HC32 chip; the transmitting end TXD2 of the sound velocity meter is respectively connected to the two 74HC08 chips, and the receiving end RXD2 of the sound velocity meter is connected to the 74HC32 chip; the transmitting end TXD3 of the level conversion module is respectively connected to the two 74HC08 chips, and the receiving end RXD3 of the level conversion module is connected to the 74HC32 chip; the output end of the control circuit is respectively connected to the two 74HC08 chips.

[0012] In one embodiment of the present invention, the first level conversion unit includes a USB to TTL circuit, which includes a CH340G chip and a crystal oscillator circuit. Pin 1 of the CH340G chip is a ground terminal, pins 2 and 3 are respectively the sending and receiving terminals of serial port data, pin 4 is a power input pin, pins 5 and 6 are directly connected to the D+ and D- data lines of the USB bus, pins 7 and 8 are the input and output pins of the crystal oscillator, and are connected to the crystal oscillator circuit to provide a clock cycle for the chip; pin 16 is a power input terminal to power the entire chip.

[0013] In one embodiment of the present invention, the USB to TTL circuit also includes power decoupling capacitors C9~C11, one end of capacitor C9 is connected to the USB power line and one end of capacitor C10 respectively, and the other end of capacitor C9 is grounded; one end of capacitor C10 is connected to pin 16, and the other end of capacitor C10 is connected to the other end of capacitor C9; one end of capacitor C11 is connected to the other end of capacitor C10, and the other end of capacitor C11 is connected to pin 4.

[0014] In one embodiment of the present invention, the second level conversion unit includes an RS485 to TTL circuit, which includes a MAX483 chip, a resistor R9, a resistor R10, and a resistor R11; pins 1 and 4 of the MAX483 chip are the sending and receiving ends of the TTL signal, and pins 6 and 7 are the in-phase receiver input and output ports and the inverting receiver input and output ports respectively; one end of the resistor R9 is connected to the power supply, and the other end of the resistor R9 is connected to pin 6; one end of the resistor R10 is connected to the other end of the resistor R9, and the other end of the resistor R10 is respectively connected to pin 7 and one end of the resistor R11, and the other end of the resistor R11 is grounded.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art:

[0016] The direct-reading sound velocity meter power supply and communication conversion circuit described in the present invention can be used to solve the long-distance power supply and communication problems of direct-reading underwater measurement equipment. The direct-reading sound velocity meter through the conversion circuit adopts USB communication and power supply, and the mobile phone data cable used in daily life can be applied to the sound velocity meter, which reduces the cost and improves the portability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0018] Figure 1 The invention discloses a block diagram of a power supply and communication conversion circuit system of a direct-reading sonic velocity meter.

[0019] Figure 2 It is a schematic diagram of a voltage boost circuit of the present invention.

[0020] Figure 3 It is a control circuit schematic diagram of the present invention.

[0021] Figure 4 It is the principle diagram of the logic gate circuit of the present invention.

[0022] Figure 5 It is the principle diagram of the RS485 to TTL circuit of the present invention.

[0023] Figure 6 It is a schematic diagram of a USB to TTL circuit of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0025] Reference Figure 1 As shown, the present invention provides a direct-reading sound velocity meter power supply and communication conversion circuit, including a level conversion module, the level conversion module includes a first level conversion unit, a logic gate unit, and a second level conversion unit connected in sequence; the first level conversion unit is connected to a host computer, and is used to convert a USB signal of the host computer into a TTL signal, and the second level conversion unit is connected to the sound velocity meter, and is used to convert the TTL signal into an RS485 signal to the sound velocity meter;

[0026] A control module, wherein the control module is connected to the logic gate unit, and the control module is used to establish communication between the host computer and the conversion module, and between the conversion module and the sound velocity meter, so that the sound velocity meter sends data to the host computer. The logic gate unit changes the output level of the control module, thereby controlling the flow direction of the sound velocity meter sending data to the host computer, so that the host computer, the conversion circuit module and the sound velocity meter can correctly receive the data at their respective receiving ends;

[0027] A boost module is connected to the host computer and the sound velocity meter respectively, and is used to boost the voltage output by the host computer and then supply it to the sound velocity meter.

[0028] like Figure 2As shown, the boost module includes a Boost boost circuit, which includes: a boost integrated module XL6009, capacitors C14~C17, resistors R12, resistors R13, diodes, and inductor L1; the boost integrated module XL6009 includes pins 1~5, and pin 1 of the boost integrated module XL6009 is grounded; pin 2 is a chip enable terminal, and the module can work normally when it is suspended or connected to a high level; pin 3 is a power switch output; pin 4 is a positive input voltage, allowing an input voltage of 5~36V, and connected to the positive electrode of the USB input voltage; pin 5 is a feedback pin, and the output voltage is sensed and adjusted through an external resistor divider network, and the output voltage = 1.25* (1+R12 / R13) = 9.36V, where 1.25 is the feedback threshold voltage.

[0029] Capacitors C14~C17 are power supply filter capacitors, inductor L1 is an energy storage element, resistors R12 and R13 determine the output voltage of the boost circuit, and the diode limits the current flow direction; one end of capacitor C14 is connected to the input voltage, and the other end is grounded; one end of capacitor C15 is connected to one end of capacitor C14 and pin 4 respectively, and the other end is connected to the other end of capacitor C15 and pin 1 respectively; one end of inductor L1 is connected to one end of capacitor C15, and the other end is connected to pin 3 and the positive electrode of the diode respectively; the cathode of the diode is connected to the output voltage; one end of resistor R12 is connected to the cathode of the diode and the output voltage respectively, and the other end is connected to pin 5 and one end of resistor R13 respectively; the other end of resistor R13 is grounded; one end of capacitor C16 is connected to one end of resistor R12 and the output voltage respectively, and the other end is grounded; one end of capacitor C17 is connected to the output voltage, and the other end is connected to the other end of the capacitor.

[0030] like Figure 3 As shown, the control module includes a control circuit, which is composed of an AT89C2051 microprocessor and peripheral devices (including a reset circuit and a crystal oscillator circuit). AT89C2051 is a low-voltage, high-performance 8-bit CMOS microprocessor with a 2K-byte flash EEPROM produced by ATMEL, which can provide a highly flexible and low-cost solution for embedded control applications. Pin 1 is a reset pin, which is reset at a high level; pins 2 and 3 are chip serial port transceiver pins, which can receive and send TTL data; pins 4 and 5 are the input and output pins of the 11.095MHz crystal oscillator, which provide a clock cycle for the chip; pins 15 to 19 are 8-bit bidirectional I / O ports, which can output control signals (logic '0' or '1'). Among them, pins 15 to 18 control the output of the connected logic gate to control the communication direction, and pin 19 controls the enable terminal of the MAX483 chip.

[0031] Considering that the sound velocity meter and the conversion circuit transmit data through RS485 half-duplex signal, it is necessary to control the communication conversion between the sound velocity meter, the conversion circuit and the host computer. The entire communication process is divided into the following three parts: establishing communication between the host computer and the conversion circuit, establishing communication between the conversion circuit and the sound velocity meter, and the sound velocity meter sending data to the host computer. The control program can determine which of the above processes is currently being performed by detecting specific characters in the data frame, and then control pins 15~19 to output specific logic levels to control the direction of data transmission.

[0032] like Figure 4 As shown, the logic gate unit includes a logic gate circuit, which is composed of two 74HC08 chips and one 74HC32 chip. Among them, TXD1 and RXD1 are the sending and receiving ends of the host computer respectively; TXD2 and RXD2 are the sending and receiving ends of the sonic velocity meter respectively; TXD3 and RXD3 are the sending and receiving ends of the conversion circuit respectively; P1.3~P1.6 are connected to the output port of the control circuit.

[0033] During the measurement process, the host computer, the conversion circuit and the sound velocity meter will communicate with each other. Therefore, an "OR" gate is used before the receiving end of each of the three parts to ensure that one of the receiving ends has the ability to receive the data sent by the other two parts. Since there is always one-to-one communication at a certain moment in the measurement process, when the two parts send data at the same time, the data sent to the receiving end after the "OR" gate is very likely to be different from the data sent by the two sending ends. To solve this problem, it is necessary to connect the input end of the "AND" gate after the sending end of the three parts, and the other input end of the "AND" gate is connected to the control circuit. According to the logical characteristics of the "AND" gate, when the control circuit outputs a low level, the output of the "AND" gate is logical 0, and it can be considered that there is no input to the other input end connected to the "AND" gate. When the control circuit outputs a high level, the output of the "AND" gate is consistent with the data of the other input end. At this time, it can be considered that the data sent by the output end of the "AND" gate is the data actually sent by a certain sending end. By changing the output level of the control circuit, the "flow direction" of the data is controlled, so that the receiving end can correctly receive the data from the output end.

[0034] like Figure 5 As shown, the second level conversion unit includes an RS485 to TTL circuit, which includes a MAX483 chip. The sonic velocity meter will work hundreds of meters underwater, and the communication distance is long. Therefore, it communicates with the conversion circuit via RS485 signals, and converts the 485 signals into TTL signals recognizable by the microcontroller through the MAX483 chip.

[0035] Pins 2 and 3 of the MAX483 chip are the enable terminals for sending and receiving data. Since 485 is half-duplex communication, only one enable terminal can be enabled at the same time, so both pins are controlled by the same I / O port of the microcontroller; pins 1 and 4 are the sending and receiving terminals of TTL signals; pins 6 and 7 are the in-phase receiver input and output ports (A) and the anti-phase receiver input and output ports (B), respectively. When VA-VB>200mV, it indicates logic '1', and when VA-VB<-200mV, it indicates logic '0', and when the voltage difference is between ±200mV, it indicates uncertainty.

[0036] One end of resistor R9 is connected to the power supply, and the other end of resistor R9 is connected to pin 6; one end of resistor R10 is connected to the other end of resistor R9, and the other end of resistor R10 is connected to pin 7 and one end of resistor R11 respectively, and the other end of resistor R11 is grounded. Resistors R9 and R11 are pull-up and pull-down resistors respectively, which are used to ensure that the unconnected MAX483 chip is in an idle state and provide network failure protection. R10 is a terminal resistor, and its resistance value is required to be approximately equal to the characteristic impedance of the transmission cable. It can be disconnected when the transmission distance is short.

[0037] like Figure 6 As shown, the first level conversion unit includes a USB to TTL circuit, which includes a CH340G chip, a crystal oscillator circuit B2, and power decoupling capacitors C9~C11. The CH340G is a USB bus conversion chip that can convert serial port signals into USB signals. Pin 1 of the chip is the ground terminal; pins 2 and 3 are the sending and receiving terminals of the serial port data respectively; pin 4 is a 3.3V power input pin. Since the high level in the logic gate circuit and the control circuit is 5V, there is no need to connect to a 3.3V power supply, and an external decoupling capacitor is sufficient; pins 5 and 6 are directly connected to the D+ and D- data lines of the USB bus; pins 7 and 8 are the input and output pins of the 12MHz crystal oscillator, which provide a clock cycle for the chip; pin 16 is the power input terminal, which supplies power to the entire chip; C9~C11 are all power decoupling capacitors. One end of capacitor C9 is connected to the USB power line and one end of capacitor C10 respectively, and the other end of capacitor C9 is grounded; one end of capacitor C10 is connected to pin 16, and the other end of capacitor C10 is connected to the other end of capacitor C9; one end of capacitor C11 is connected to the other end of capacitor C10, and the other end of capacitor C11 is connected to pin 4.

[0038] The present invention can be applied to solve the long-distance power supply and communication problems of direct-reading underwater measuring equipment. The direct-reading sound velocity meter through the conversion circuit adopts USB communication and power supply, and the mobile phone data cable used in daily life can be applied to the sound velocity meter, which reduces the cost and improves the portability of the equipment.

[0039] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A direct-reading sonic velocity meter power supply and communication conversion circuit, characterized in that: include A level conversion module, the level conversion module includes a first level conversion unit, a logic gate unit, and a second level conversion unit connected in sequence; the first level conversion unit is connected to a host computer and is used to convert a USB signal of the host computer into a TTL signal, and the second level conversion unit is connected to a sound velocity meter and is used to convert the TTL signal into an RS485 signal for the sound velocity meter; wherein the first level conversion unit includes a USB to TTL circuit, and the second level conversion unit includes an RS485 to TTL circuit; A control module is connected to the logic gate unit. The control module is used to establish communication between the host computer and the level conversion module, and between the level conversion module and the sound velocity meter, so that the sound velocity meter sends data to the host computer. The logic gate unit controls the flow direction of the sound velocity meter sending data to the host computer by changing the output level of the control module, so that the host computer, the level conversion module and the sound velocity meter can correctly receive the data at their respective receiving ends; wherein the control program in the control module determines whether the current process is the process of establishing communication between the host computer and the level conversion module, between the level conversion module and the sound velocity meter, or the process of the sound velocity meter sending data to the host computer by detecting specific characters in the data frame, and then controls pins 15-19 to output specific The logic level is used to control the data transmission direction; at the same time, during the measurement operation of the control program, the host computer, the level conversion module and the sound velocity meter will communicate with each other, so an "OR" gate is used before the receiving ends of the three parts to ensure that one of the receiving ends has the ability to receive data sent by the other two parts; the control module includes a control circuit, which includes an AT89C2051 microprocessor, and the AT89C2051 microprocessor includes pins 1 to 19, pin 1 is a reset pin, high level reset; pins 2 and 3 are chip serial port transceiver pins for receiving and sending TTL data; pins 4 and 5 are crystal oscillator input and output pins, which provide a clock cycle for the chip; pins 15 to 19 are 8-bit bidirectional I / O ports for outputting control signals; A boost module is connected to the host computer and the sound velocity meter respectively, and is used to boost the voltage output by the host computer and then supply it to the sound velocity meter.

2. A direct-reading sonic velocity meter power supply and communication conversion circuit according to claim 1, characterized in that: The boost module includes a Boost boost circuit, which includes: a boost integrated module XL6009, capacitors C14-C17, a resistor R12, a resistor R13, a diode, and an inductor L1; The boost integrated module XL6009 includes pins 1 to 5, wherein pin 1 is grounded, pin 2 is a chip enable terminal, pin 3 is a power switch output, pin 4 is an input voltage positive, and pin 5 is a feedback pin; One end of capacitor C14 is connected to the input voltage, and the other end of capacitor C14 is grounded; one end of capacitor C15 is connected to one end of capacitor C14 and pin 4 respectively, and the other end of capacitor C15 is connected to the other end of capacitor C14 and pin 1 respectively; one end of inductor L1 is connected to one end of capacitor C15, and the other end of inductor L1 is connected to pin 3 and the positive electrode of the diode respectively, and the cathode of the diode is connected to the output voltage; one end of resistor R12 is connected to the negative electrode of the diode and the output voltage respectively, and the other end of resistor R12 is connected to pin 5 and one end of resistor R13 respectively, and the other end of resistor R13 is grounded; one end of capacitor C16 is connected to one end of resistor R12 and the output voltage respectively, and the other end of capacitor C16 is grounded; one end of capacitor C17 is connected to the output voltage, and the other end of capacitor C17 is connected to the other end of the capacitor.

3. A direct-reading sonic velocity meter power supply and communication conversion circuit according to claim 1, characterized in that: The logic gate unit comprises a logic gate circuit, including two 74HC08 chips and one 74HC32 chip; the transmitting end TXD1 of the host computer is respectively connected to the two 74HC08 chips, and the receiving end RXD1 of the host computer is connected to the 74HC32 chip; the transmitting end TXD2 of the sound velocity meter is respectively connected to the two 74HC08 chips, and the receiving end RXD2 of the sound velocity meter is connected to the 74HC32 chip; the transmitting end TXD3 of the logic gate unit in the level conversion module is respectively connected to the two 74HC08 chips, and the receiving end RXD3 of the logic gate unit in the level conversion module is connected to the 74HC32 chip; the output end of the control circuit is respectively connected to the two 74HC08 chips.

4. A direct-reading sonic velocity meter power supply and communication conversion circuit according to claim 1, characterized in that: The USB to TTL circuit includes a CH340G chip and a crystal oscillator circuit. Pin 1 of the CH340G chip is a ground terminal, pins 2 and 3 are respectively the sending and receiving terminals of serial port data, pin 4 is connected with a capacitor to decouple power supply noise, pins 5 and 6 are directly connected to the D+ and D- data lines of the USB bus, and pins 7 and 8 are the input and output pins of the crystal oscillator, and are connected to the crystal oscillator circuit to provide a clock cycle for the chip. Pin 16 is the main power input terminal, which provides power for the entire chip.

5. A direct-reading sonic velocity meter power supply and communication conversion circuit according to claim 4, characterized in that: The USB to TTL circuit also includes power decoupling capacitors C9~C11, one end of capacitor C9 is connected to the USB power line and one end of capacitor C10 respectively, and the other end of capacitor C9 is grounded; one end of capacitor C10 is connected to pin 16, and the other end of capacitor C10 is connected to the other end of capacitor C9; one end of capacitor C11 is connected to the other end of capacitor C10, and the other end of capacitor C11 is connected to pin 4.

6. A direct-reading sonic velocity meter power supply and communication conversion circuit according to claim 1, characterized in that: The RS485 to TTL circuit includes a MAX483 chip, a resistor R9, a resistor R10, and a resistor R11; Pins 1 and 4 of the MAX483 chip are the sending and receiving ends of the TTL signal, and pins 6 and 7 are the in-phase receiver input and output ports and the inverting receiver input and output ports respectively; One end of resistor R9 is connected to the power supply, and the other end of resistor R9 is connected to pin 6; one end of resistor R10 is connected to the other end of resistor R9, and the other end of resistor R10 is respectively connected to pin 7 and one end of resistor R11, and the other end of resistor R11 is grounded.

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