CN218673760U - Low-power consumption flowmeter circuit - Google Patents

Abstract

The utility model discloses a concrete flowmeter device circuit, including STM32L series singlechip, frequency conditioning unit, display element, memory cell and battery cell, the frequency conditioning unit is used for carrying out the plastic to the frequency signal of input to compensate the pulse number to the loss, output equivalent pulse, the collection of data is accomplished to STM32L series singlechip, stores through memory cell, and shows through display element, and the battery cell provides the power for STM32L series singlechip. The utility model discloses a low-power consumption flowmeter circuit, including singlechip, frequency conditioning circuit, memory cell, battery cell and display element. The single chip microcomputer is combined with the frequency acquisition circuit, pulse counting loss can be accurately compensated by adopting a shutdown mode and a real-time clock mode of an STM32l series single chip microcomputer and a low-power consumption counter, high-precision data acquisition is realized, the power consumption of the running device is greatly reduced, and the service life of a battery is prolonged.

Description

Low-power consumption flowmeter circuit

Technical Field

The utility model belongs to the technical field of the semiconductor is made, concretely relates to low-power consumption flowmeter circuit.

Background

In the industrial and civil fields, the occasions needing to collect the liquid and gas flow are frequently encountered, one method is to obtain square waves by signal conditioning through devices such as a Hall sensor or an electromagnetic coil, obtain actual flow data by collecting the frequency of the square waves through a certain conversion relation, display and transmit the actual flow data, and accurately collect relevant data under the condition of small flow. Under the inconvenient external power supply's of external environment condition, often need the battery to supply power, often attach attention to the size of collection system consumption under the battery powered situation, consequently need solve the control problem of consumption, guarantee that the device can work for a long time under the condition of battery powered.

Because the low-power consumption technology is important for the battery-powered flowmeter, the flowmeter with the low-power consumption characteristic under the battery-powered condition needs to be designed urgently, the acquisition accuracy needs to be met, pulses can not be lost under the condition of small flow, and the measurement accuracy is ensured. The STM32l series single chip microcomputer widely used at present is a 32-bit ultra-low power consumption MCU product of an ideological semiconductor, and is widely applied to the occasions of liquid and gas flow collection, usually, an interruption collection mode is used in the flow collection process, namely, the system is in a halt or sleep state under the condition of no pulse, the interruption is generated once when a pulse is received for counting, and a collection program is awakened regularly.

Above-mentioned scheme advantage is that it requires to gather accurate performance, but there is the too big problem of consumption, consequently, need to prolong STM32l series singlechip at the time of dormant state, further reduce the consumption, it still can count to need STM32l series singlechip under the off-state, STM32l series singlechip has provided low-power consumption timer (LPTIM) specially, the difference with ordinary timer is that LPTIM still can work under sleep or the off-mode, consequently can realize the count under the off-mode with the help of the low-power consumption timer, but STM32l series singlechip has the characteristic that needs 5 continuous pulses just can start the count after the count value is initialized at every turn, can't gather at less than or equal to 5Hz frequency signal, often can cause the loss of flow, can't realize accurate measurement, consequently, need to design a circuit that can realize accurate measurement and low-power consumption simultaneously.

Disclosure of Invention

An object of the utility model is to provide a low-power consumption flowmeter circuit, including singlechip, frequency conditioning circuit, memory cell, battery cell and display element. The single chip microcomputer is combined with the frequency acquisition circuit, pulse counting loss can be accurately compensated by adopting a shutdown mode and a real-time clock mode of an STM32l series single chip microcomputer and a low-power consumption counter, high-precision data acquisition is realized, the power consumption of the running device is greatly reduced, and the service life of a battery is prolonged.

The utility model provides a technical scheme that its technical problem adopted is: the utility model provides a concrete flowmeter device circuit, includes STM32L series singlechip, frequency conditioning unit, display element, memory cell and battery cell, and the frequency conditioning unit is used for carrying out the plastic to the frequency signal of input to compensate the pulse number of loss, output equivalent pulse, STM32L series singlechip accomplish the collection of data, store through memory cell, and show through the display element, the battery cell provides the power for STM32L series singlechip.

Further, the frequency conditioning unit comprises an RC filter circuit, a Schmitt trigger and a NOT gate circuit, frequency signals enter the Schmitt trigger for further conditioning after being filtered by the RC filter circuit, the conditioned frequency signals are divided into two paths, one path is used for outputting equivalent pulse signals, the other path enters the NAND gate circuit together with compensation pulses generated by the single chip microcomputer for logic operation, and the frequency signals generated after the operation are sent to the STM32L series single chip microcomputer for detection and used for internal calculation.

Further, the Schmitt trigger shapes the input frequency signal, the model of the Schmitt trigger is SN74HC14, and the signal conditioned by the Schmitt trigger is converted into a 3V square wave signal.

Further, the output signal of the Schmitt trigger is directly transmitted to a equivalent pulse signal wiring terminal of the flowmeter and used for type evaluation and metering of the flowmeter.

Further, the battery unit is a replaceable battery, and the battery unit is a lithium thionyl chloride battery.

Furthermore, the COG liquid crystal display module adopted by the display unit has the power consumption of less than 80uA during working and the working voltage of 3V.

Further, the memory module selected by the memory unit is AT24C256C, has 256K memory space, and uses I2C bus to complete communication.

Further, the model of the selected STM32L series single chip microcomputer is STM32L053R8T6.

The utility model discloses following beneficial effect has: the utility model discloses a low-power consumption flowmeter circuit, including singlechip, frequency conditioning circuit, memory cell, battery cell and display element. The single chip microcomputer is combined with the frequency acquisition circuit, and the stop mode and the real-time clock mode of the STM32l series single chip microcomputer and the low-power-consumption counter are adopted, so that the pulse counting loss can be accurately compensated, high-precision data acquisition is realized, the power consumption of the device in operation is greatly reduced, and the service life of a battery is prolonged.

The battery unit is a replaceable battery, the lithium thionyl chloride battery is preferably selected here to ensure the stability of output voltage, the battery is converted into stable 3V voltage through the low-dropout linear voltage regulator, and power supply of the Hall sensor for sensing the flow can be output.

The frequency conditioning unit 1 comprises an RC low-pass filter circuit, a Schmitt trigger and an NAND gate logic circuit, and filters high-frequency interference after passing through the RC low-pass filter circuit aiming at the frequency signal output by the flow sensor, so as to ensure that the signal exceeding 1MHz is effectively attenuated.

Drawings

Fig. 1 is a system block diagram of a liquid flow meter device circuit according to an embodiment of the present invention;

fig. 2 is a block diagram of a frequency conditioning unit according to an embodiment of the present invention;

fig. 3 is a block flow diagram provided by the embodiment of the present invention.

Wherein: 1. the device comprises a frequency conditioning unit, a display unit, a storage unit, a battery unit, a STM32L series single chip microcomputer, a RC filter circuit, a Schmitt trigger, a NOT gate circuit and a frequency control unit, wherein the frequency conditioning unit comprises 2, the display unit, 3, the storage unit, 4, the battery unit, 5, the STM32L series single chip microcomputer, 6, the RC filter circuit, 7, the Schmitt trigger and 8.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings.

As shown in figure 1, a concrete flowmeter device circuit, including STM32L series singlechip 5, frequency conditioning unit 1, display element 2, memory cell 3 and battery cell 4, frequency conditioning unit 1 is used for carrying out the shaping to the frequency signal of input to compensate the pulse number of loss, output equivalent pulse, STM32L series singlechip 5 accomplishes the collection of data, store through memory cell 3, and show through display element 2, battery cell 4 provides the power for STM32L series singlechip 5.

As shown in fig. 2, the frequency conditioning unit 1 includes an RC filter circuit 6, a schmitt trigger 7 and a not gate circuit 8, the frequency signal is filtered by the RC filter circuit 6 and enters the schmitt trigger 7 for further conditioning, the conditioned frequency signal is divided into two paths, one path is used for outputting equivalent pulse signals, the other path enters the nand gate circuit 8 together with compensation pulses generated by the single chip microcomputer for logic operation, and the frequency signal generated after the operation is sent to the STM 32L-series single chip microcomputer 5 for detection and used for internal calculation.

The Schmitt trigger 7 shapes the input frequency signal, the model of the Schmitt trigger 7 is SN74HC14, and the signal conditioned by the Schmitt trigger is converted into a 3V square wave signal.

And the output signal of the Schmitt trigger 7 is directly transmitted to a equivalent pulse signal wiring terminal of the flowmeter and is used for type evaluation and metering of the flowmeter.

The battery unit 4 is a replaceable battery, and the battery unit 4 is a lithium thionyl chloride battery.

The COG liquid crystal display module adopted by the display unit 2 has the power consumption less than 80uA and the working voltage of 3V during working.

The memory module selected by the memory unit 3 is AT24C256C, has 256K memory space, and uses I2C bus to complete communication.

The model of the STM32L series single chip microcomputer 5 is STM32L053R8T6.

As shown in fig. 3, after the STM 32L-series single-chip microcomputer 5 is started, it first initializes, reads the data associated with the storage unit 3, sets the real-time clock RTC to generate an interrupt once a second, initializes the display unit 2 and the low-power-consumption timer, displays the accumulated flow data, and enters a shutdown mode.

When the time interval (1 second for 1 time) set by a real-time clock (RTC) is reached, the system exits the shutdown mode, enters a normal working mode, calculates the number of pulses collected by the low-power consumption timer, and converts the number of the pulses into instantaneous flow and accumulated flow through an instrument coefficient preset in advance.

In order to further improve the stability of the instantaneous flow and prevent measurement errors caused by fluctuation of the instantaneous flow, the result of the moving average filtering is used as the value of the instantaneous flow.

After the instantaneous flow and the cumulative flow are calculated and displayed, the cumulative flow data is stored in the storage unit 3 at a frequency of once every 5 minutes. In order to prevent the overflow of the low-power consumption counter, the counter is cleared and enters a shutdown state again.

When the utility model discloses be applied to the gas flow timing, because the compressibility of gas and the characteristic that easily receives the temperature influence, need add temperature sensor and pressure sensor, convert into gaseous standard volume under standard atmospheric pressure, the room temperature 20 ℃ condition according to the gaseous equation.

The utility model discloses not be limited to above-mentioned embodiment, anybody should learn the structural change who makes under the teaching of the utility model, all with the utility model discloses have the same or close technical scheme, all fall into the utility model discloses an within the protection scope.

The technology, shape and construction parts which are not described in detail in the present invention are all known technology.

Claims (7)

1. A low-power consumption flowmeter circuit characterized by: the frequency modulation unit is used for shaping input frequency signals, compensating lost pulse numbers and outputting equivalent pulses, the STM32L series single-chip microcomputer finishes data acquisition, the data are stored through the storage unit and displayed through the display unit, the battery unit provides power for the STM32L series single-chip microcomputer, the frequency modulation unit comprises an RC filter circuit, a Schmidt trigger and a NOT gate circuit, the frequency signals are filtered by the RC filter circuit and then enter the Schmidt trigger for further modulation, the frequency signals after modulation are divided into two paths, one path is used for outputting the equivalent pulse signals, the other path enters a NAND gate circuit together with the compensation pulses generated by the single-chip microcomputer for logic operation, and the frequency signals generated after operation are sent to the STM32L series single-chip microcomputer for detection and internal calculation.

2. A low power consumption flow meter circuit according to claim 1, wherein: the Schmitt trigger shapes input frequency signals, the model of the Schmitt trigger is SN74HC14, and the signals conditioned by the Schmitt trigger are converted into 3V square wave signals.

3. A low power consumption flow meter circuit according to claim 1, wherein: and the output signal of the Schmitt trigger is directly transmitted to an equivalent pulse signal wiring terminal of the flowmeter and is used for type evaluation and metering of the flowmeter.

4. A low power consumption flow meter circuit according to claim 1, wherein: the battery unit is a replaceable battery, and the battery unit is a lithium thionyl chloride battery.

5. A low power consumption flow meter circuit according to claim 1, wherein: the COG liquid crystal display module adopted by the display unit has the power consumption of less than 80uA and the working voltage of 3V during working.

6. A low power consumption flow meter circuit according to claim 1, wherein: the memory module selected by the memory unit is AT24C256C, has 256K memory space, and uses I2C bus to complete communication.

7. A low power consumption flowmeter circuit according to claim 1 wherein: the model of the STM32L series single chip microcomputer is STM32L053R8T6.

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