CN209117104U - Based on MSP430FW427 without magnetic low-power consumption water meter device - Google Patents

Abstract

The utility model relates to a non-magnetic low-power consumption water meter device based on MSP430FW427. Including the MSP430FW427 single-chip microcomputer module set in the non-magnetic water meter and the flow detection module, liquid crystal display module, storage module, motor module, serial port module, and a power supply module for supplying power to the whole device connected to the MSP430FW427 single-chip microcomputer module. The flow detection module The module includes an LC sensor circuit for sensing the oscillating waveform generated when the runner metal area of the non-magnetic water meter and the non-metal area of the runner pass through. The LC sensor circuit is connected to the MSP430FW427 MCU module through the SCAN/IF interface of the MSP430FW427 MCU module. The motor module includes a valve motor drive circuit and a valve switch motor connected to the valve motor drive circuit. The utility model can realize the accuracy of water consumption measurement, and can realize the control of the electronic valve, and the power consumption of the whole device is low.

Description

Non-magnetic low-power water meter device based on MSP430FW427

technical field

The utility model relates to a non-magnetic low-power consumption water meter device based on MSP430FW427.

Background technique

With the continuous development of electronic technology, the smart water meter industry has sprung up like mushrooms after a spring rain. sensors, etc. However, general water meters with magnetic sensors are easily disturbed by the magnetic field environment, resulting in metering errors and missing metering, and are easily used by dishonest people. Moreover, with the growth of the use time, the permanent magnet device with the magnetic water meter will attract the metal impurities in the water, which will accumulate continuously and eventually cause measurement errors. The non-magnetic water meter is a new generation of smart water meters designed to overcome the above problems. The MSP430FW42X series microcontroller from Texas Instruments provides the basis for the design of non-magnetic water meters. The integrated SCAN/IF module and 96-segment LCD driver on the chip provide great convenience for non-magnetic water meters. Therefore, the design of non-magnetic water meters will Leading the smart water meter industry to a new path.

This device is designed with MSP430FW427 as the main control chip, receives sensor signals and performs data calculation and processing, then controls the electronic valve, and displays the measurement results on the segment LCD. The accuracy of water metering, electronic valve control, low power consumption and other issues are the main research and implementation functions of this design.

Through the LC sensor, the oscillating waveform generated when the metal sheet area of the runner passes through the inductance and the oscillating waveform generated when the non-metallic area of the runner passes through the inductance are read, and then the SCAN/IF interface receives the oscillating waveform data, and compares it with the set reference voltage. A digital signal is generated, so that the single-chip microcomputer obtains and processes the data of the number of turns of the runner, and then counts.

The use of segment LCD to display measurement data makes the measurement data more intuitive and clear, allowing users to read effective information conveniently and intuitively.

The electronic valve drive uses the H bridge circuit to drive the motor, and selects the switch of the valve through the model output by the single-chip microcomputer. A value preset by the program, when the water metering exceeds this value, the motor turns to close the valve.

Since the measured water consumption data will be lost when the microcontroller is powered off, this design has an E ² PROM module for storing data to ensure that the previously measured water consumption can be read back when the battery restores power after a power failure. .

SUMMARY OF THE INVENTION

The purpose of the utility model is to provide a non-magnetic low-power consumption water meter device based on MSP430FW427, which can realize the accuracy of water consumption measurement, and can realize the control of electronic valves, and the whole device has low power consumption.

In order to achieve the above-mentioned purpose, the technical scheme of the present utility model is: a non-magnetic low-power consumption water meter device based on MSP430FW427, comprising the MSP430FW427 single-chip microcomputer module arranged in the non-magnetic water meter and the flow detection module, the liquid crystal display module connected with the MSP430FW427 single-chip microcomputer module. A display module, a storage module, a motor module, a serial port module, a power supply module for supplying power to the entire device, and the flow detection module includes the oscillation generated when the metal sheet area of the runner and the non-metal area of the runner pass through the non-magnetic water meter. The waveform LC sensor circuit is connected with the MSP430FW427 single-chip microcomputer module through the SCAN/IF interface of the MSP430FW427 single-chip microcomputer module, and the motor module includes a valve motor drive circuit and a valve switch motor connected with the valve motor drive circuit.

In an embodiment of the present invention, the liquid crystal display module adopts a segment LCD.

In an embodiment of the present invention, the storage module adopts an E ² PROM storage module.

In an embodiment of the present invention, the valve motor drive circuit adopts an H-bridge circuit to control the forward and reverse rotation of the valve switch motor.

In an embodiment of the present utility model, the serial port module adopts MAX232.

In an embodiment of the present invention, the LC sensor circuit includes a first inductor, a second inductor, and first to fifth capacitors, one end of the first inductor is connected to one end of the first capacitor and one end of the second capacitor, and One end of the first inductor is also connected to the SCAN/IF interface, and one end of the second inductor is connected to the other end of the first inductor, the other end of the first capacitor, the other end of the second capacitor, one end of the third capacitor, and the fourth One end of the capacitor and one end of the fifth capacitor are connected, and one end of the second inductor is also connected to the SCAN/IF interface, and the other end of the second inductor is connected to the other end of the third capacitor and the other end of the fourth capacitor. The other end of the second inductor is also connected to the SCAN/IF interface, and the other end of the fifth capacitor is connected to GND.

Compared with the prior art, the utility model has the following beneficial effects: the device of the utility model can realize the accuracy of water consumption measurement, and can realize the control of the electronic valve, and the power consumption of the whole device is low.

Description of drawings

Fig. 1 is the system structure block diagram of the non-magnetic low power consumption water meter device based on MSP430FW427 of the present invention.

Fig. 2 is the minimum system circuit of MSP430FW427 adopted by the utility model.

Fig. 3 is the LC sensor circuit adopted by the present invention.

FIG. 4 is a segment LCD hardware circuit adopted by the present invention.

FIG. 5 is the H-bridge motor drive circuit adopted by the present invention.

Fig. 6 is the E ² PROM storage module circuit adopted by the present invention.

7 is a schematic diagram of the SCAN/IF measurement composition and work flow of the present invention.

Fig. 8 is the serial port module circuit adopted by the present invention.

Detailed ways

The technical solutions of the present utility model will be described in detail below with reference to the accompanying drawings.

The utility model provides a non-magnetic low-power consumption water meter device based on MSP430FW427, which comprises a MSP430FW427 single-chip microcomputer module arranged in the non-magnetic water meter, a flow detection module, a liquid crystal display module, a storage module and a motor module connected with the MSP430FW427 single-chip microcomputer module. , a serial port module, a power supply module for powering the entire device, the flow detection module includes an LC sensor circuit for sensing the oscillating waveform generated when the non-magnetic water meter's runner metal area and the runner non-metal area pass through. The sensor circuit is connected to the MSP430FW427 single-chip microcomputer module through the SCAN/IF interface of the MSP430FW427 single-chip microcomputer module. The motor module includes a valve motor drive circuit and a valve switch motor connected to the valve motor drive circuit.

The liquid crystal display module adopts segment LCD. The storage module adopts E ² PROM storage module. The valve motor drive circuit adopts an H bridge circuit to control the forward and reverse rotation of the valve switch motor. The serial port module adopts MAX232.

The LC sensor circuit includes a first inductor, a second inductor, and first to fifth capacitors, one end of the first inductor is connected to one end of the first capacitor and one end of the second capacitor, and one end of the first inductor is also connected to the SCAN/IF interface connection, one end of the second inductor is connected to the other end of the first inductor, the other end of the first capacitor, the other end of the second capacitor, one end of the third capacitor, one end of the fourth capacitor, and one end of the fifth capacitor connected, and one end of the second inductor is also connected to the SCAN/IF interface, the other end of the second inductor is connected to the other end of the third capacitor and the other end of the fourth capacitor, and the other end of the second inductor is also connected to the The SCAN/IF interface is connected, and the other end of the fifth capacitor is connected to GND.

The following is the specific implementation process of the present invention.

The utility model is a non-magnetic low power consumption water meter device based on MSP430FW427, uses MSP430FW427 as the main control chip, after initial setting, the chip works in a low power consumption mode, and external devices can be separated from the CPU to work in a low power consumption mode. After the SCAN/IF module is started, it automatically records the data, and only wakes up the CPU when necessary to process the obtained data. The timer counter 3 waits for the occurrence of an interrupt. After receiving the interrupt signal, it receives the serial port data, processes the data, and the CPU responds according to the received data, such as switching valves, displaying water consumption and so on.

Externally equipped with valve motor drive, LC sensor, E ² PROM data storage module, and liquid crystal display module, the interface required for serial communication is reserved. The above modules constitute the overall design of the non-magnetic water meter. The system structure diagram is shown in Figure 1. Show.

Each hardware module adopted by the device of the present utility model is as follows:

1. Main control chip MSP430FW427

The MSP430FW42x series of microcontrollers are the latest special MCU chips developed by TI for electronic flow and rotational motion detection. The device's ultra-low power architecture and flow detection module not only extend battery life, but also improve the accuracy and performance of the meter. Typical applications for the MSP430FW42x include thermal meters, hot and cold water meters, gas meters and industrial flow meters, anemometers, and other rotational detection applications. MSP430FW427 chip is one of the chips in this series. The size of its Flash memory is 32KB, and the size of RAM is 1KB. It is cheap and can further save costs under the condition that it meets the functional requirements. Its minimum system circuit is shown in Figure 2.

2. LC sensor circuit

The LC sensor is composed of two sets of LC oscillation circuits ^[10] . The original circuit and function of the LC sensor have been introduced in the previous article. Here we will introduce the construction of the peripheral devices required for the LC oscillation circuit in detail. In Figure 3, the inductor L1 and the capacitor C22 is connected in parallel, one end is connected to the SIFCOM pin of MSP430FW427, and the other end is connected to SIFCH1; the inductor L2 is connected in parallel with the capacitor C23, one of the pins is connected to the SIFCOM pin, and the other pin is connected to the SIFCH0 pin. The C24 and C25 bits are left blank for later testing. One pin of capacitor C6 is connected to the SIFCOM pin, and the other pin is grounded for filtering.

The selection of inductance and capacitance matching value of LC sensor

For the calculation of the LC oscillation circuit, because the damping change caused by the frequency can be basically ignored, the following LC oscillation formula is obtained:

Among them, fr is the oscillation frequency; L is the inductance; C is the capacitance; in the following table 3-1, the frequencies that can be measured by using different capacitance and inductance values are listed. The inductance and capacitance of different combination parameters were measured on the LC sensor, and the output waveform was tested. After data comparison, the combination of a large I-shaped inductance of 140μH and a capacitance of 820pF was finally selected.

3. LCD liquid crystal display circuit

The MSP430FW427 single-chip microcomputer integrates a module that can drive a 96-segment liquid crystal display. The COM0-COM3 pins are the common terminals, and the segment you want to display can be selected by programming. This design uses four COM pins and 20 segment pins. A total of 24 IO ports on the microcontroller are used. The common terminals COM0-COM3 are respectively connected to COM0-COM3 on the microcontroller, and the segment pins S0-S19 are respectively connected to the microcontroller. S0-S19, the schematic diagram is shown in Figure 4.

4. Valve motor drive circuit

As shown in Figure 5, the H-bridge motor circuit is a mature DC motor drive circuit. Its main function is to enable the DC motor to rotate forward and reverse. Because its circuit structure resembles the English letter "H", it is called "H". H-bridge circuit. This design is to use the H bridge circuit to control the rotation of the valve switch motor, and to control the on and off of the MOS tube through the IO port on the MCU, so that the polarity of the current can be changed to change the rotation direction of the motor. Since the valve switch does not need to use speed regulation, it only needs to output high and low level signals from IO. When K1 input signal 1, K2 input signal 0, the transistor Q5 is saturated and cut off, and Q6 is turned on. At this time, Q4 and Q3 are also Correspondingly, the current flows from J11 to J12; otherwise, Q5 is turned on and Q6 is turned off. At this time, Q1 and Q2 are turned on, and the current flows from J12 to J11.

5. E ² PROM memory module circuit

AT24C64 is a 128-word programmable read-only memory that can be erased repeatedly by power supply, namely E ² PROM. It uses serial port to read and write data, with few peripheral circuits and stable data storage. The point WP shown in Figure 6 is connected to the P6.7 pin of the MCU, and is connected to the VCC pin of the AT24C01. The program can control the P6.7 pin to output high and low levels to determine whether to make the data storage chip work, so as to achieve The purpose of reducing power consumption.

6. Serial port module circuit

As shown in Figure 8, the serial port module circuit of the present invention completes the level conversion through the MAX232 chip, and exchanges information with other external devices

The SCAN/IF measurement composition and workflow of the present utility model are as follows:

The block diagram of the SCAN/IF measurement is shown in Figure 7. The mechanical rotation signal passes through the LC sensor, and the rotation converts the electrical signal to the SCAN/IF inside the MSP430FW427.

The flow detection module SCAN/IF integrated in the microcontroller MSP430FW427 can identify the rotation of the rotating device under low power consumption. The SCAN/IF module has three parts: Analog Front End (AFE), Signal Processing State Machine (PSM), Timing State Machine (TSM) ). The SCAN/IF interface uses these three parts to complete the measurement of one rotation through the four processes of excitation, delay, detection and counting. The excitation time is very short, the SCAN/IF module acts as a power supply in the LC oscillator circuit to charge the capacitor, and then immediately disconnects, allowing the LC oscillator circuit to vibrate, resulting in a damped oscillating sinusoidal waveform due to eddy currents. Since it takes a period of time for the decaying signal to appear, it needs a delay to measure the decaying waveform. Then the module detects the attenuation waveform. According to the attenuation of the waveform, it can be judged whether the inductance is in the metal area or non-metal area of the rotating device. By comparing with the previous position of the inductor, the rotation direction and the number of turns of the rotating device can be measured. .

In the process of actual hardware development and design, it is usually necessary to consider whether the overall power consumption of the hardware is required, especially for life-related products such as water meters, the lower the power consumption, the better the interests of users and the improvement of design competitiveness. The power consumption of the hardware is generally related to the MCU itself, the programming and design of the program, and the number of external functional circuits. Generally, we reduce the power consumption of the product by reducing the working frequency of the MCU, reducing the working voltage of the MCU, reducing unnecessary external circuits, setting the unused GPIO as the output mode, and selecting the appropriate working mode of the microcontroller.

The above are the preferred embodiments of the present utility model, all changes made according to the technical solutions of the present utility model, when the resulting functional effects do not exceed the scope of the technical solutions of the present utility model, belong to the protection scope of the present utility model.

Claims (6)

1. it is a kind of based on MSP430FW427 without magnetic low-power consumption water meter device, which is characterized in that including be set to water meter with nonmagnetic in MSP430FW427 one-chip computer module and the flow detection module being connect with the MSP430FW427 one-chip computer module, liquid crystal display mode Block, memory module, motor module, serial port module, the power supply module for powering for whole device, the flow detection module packet Include the LC sensor of the waveform generated when runner metal section and runner non-metallic areas for incuding water meter with nonmagnetic are passed through Circuit, the SCAN/IF interface and MSP430FW427 single-chip microcontroller which passes through MSP430FW427 one-chip computer module Module connection, the motor module include valve driving machine driving circuit and the valve switch that connect with the valve driving machine driving circuit Motor.

2. it is according to claim 1 based on MSP430FW427 without magnetic low-power consumption water meter device, which is characterized in that it is described LCD MODULE uses section-type LCD.

3. it is according to claim 1 based on MSP430FW427 without magnetic low-power consumption water meter device, which is characterized in that it is described Memory module uses E²PROM memory module.

4. it is according to claim 1 based on MSP430FW427 without magnetic low-power consumption water meter device, which is characterized in that it is described Valve driving machine driving circuit uses H bridge type circuit, to realize the positive and negative rotation of control valve switching motor.

5. it is according to claim 1 based on MSP430FW427 without magnetic low-power consumption water meter device, which is characterized in that it is described Serial port module uses MAX232.

6. it is according to claim 1 based on MSP430FW427 without magnetic low-power consumption water meter device, which is characterized in that it is described LC sensor circuit includes the first inductance, the second inductance, the first to the 5th capacitor, and the one of one end of the first inductance and first capacitor One end connection at end, the second capacitor, and one end of the first inductance is also connect with the SCAN/IF interface, one end of the second inductance With the other end of the first inductance, the other end of first capacitor, the other end of the second capacitor, one end of third capacitor, the 4th capacitor One end, the 5th capacitor one end connection, and one end of the second inductance is also connect with the SCAN/IF interface, the second inductance The other end is connect with the other end of the other end of third capacitor, the 4th capacitor, the other end of the second inductance also with the SCAN/IF Interface connection, the other end of the 5th capacitor are connected to GND.