CN216596242U - Low-power consumption wake-up circuit for electronic remote transmission water meter bus - Google Patents

Abstract

The utility model provides a low-power consumption wake-up circuit of an electronic remote water meter bus, which comprises a slave equipment main control unit, an RS485 chip and an RS485 bus, wherein the slave equipment main control unit comprises an MCU (microprogrammed control unit) supporting dormancy, and a tri-state buffer chip is added to provide a wake-up signal to equipment when the RS485 chip is dormant, so that the RS485 bus network has real-time wake-up capability on the premise of meeting the low-power consumption requirement, can completely and effectively replace a special chip such as MAX3471 and reduce the cost.

Description

Low-power consumption wake-up circuit for electronic remote transmission water meter bus

Technical Field

The utility model relates to the technical field of electronic water meters, in particular to a low-power consumption wake-up circuit of an electronic remote transmission water meter bus.

Background

The RS485 bus is one of communications commonly used in the field of industrial communication at present, and is frequently used in intelligent instruments, intelligent home and industrial control. If the current RS485 bus is to be applied in a battery-powered environment or in the field of micro power consumption, one way is to use a special chip with very low current in the receive mode, such as MAX 3471. Or the bus is abandoned to wake up the device, the device is used for self-waking up, and the RS485 chip with low standby power consumption can be used.

The special chip with very low current in the receiving mode, such as MAX3471, has the disadvantage of high price, and it is necessary to replace this chip for each node in the bus, which is undoubtedly very costly.

The bus is abandoned to wake up the capacity of the equipment, the equipment is used for self-waking up, and at the moment, the RS485 chip with low standby power consumption can be used. Although the disadvantage of high cost can be avoided by the method, abandoning the bus wakeup will undoubtedly reduce the real-time performance of the whole system, and if the device end wakeup time interval is shortened for the real-time performance, the power consumption of the whole system will be increased, and the advantage of the power consumption is not provided.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a low-power-consumption wake-up circuit for an electronic remote water meter bus, which is designed to solve the problems in the prior art by adding a circuit of a tri-state buffer chip.

The purpose of the utility model is realized by the following technical scheme:

the utility model provides an electron teletransmission water gauge bus low-power consumption awakening circuit, includes slave unit master control, RS485 chip, RS485 bus, the slave unit master control integration has the MCU that supports dormancy, its characterized in that: the circuit also comprises a tri-state buffer chip;

the RS485 chip and the tri-state buffer chip are respectively and electrically connected with the MCU, and the other ends of the RS485 chip and the tri-state buffer chip are respectively and electrically connected with the RS485 bus.

Further, an RX signal, a TX signal, an RE signal and a DE signal of the MCU are electrically connected with the RS485 chip;

a sleep _ en signal and an RX signal of the MCU and an A signal of the RS485 bus are electrically connected with a tri-state buffer chip;

the RS485 chip is electrically connected with the resistor R3, and the other end of the R3 is electrically connected with a B signal of an RS485 bus; the RS485 chip is electrically connected with the resistor R5, and the other end of the R5 is electrically connected with an A signal of the RS485 bus;

the power supply + signal of the RS485 bus is respectively and electrically connected with a VCC signal of the MCU, an RS485 chip and a tri-state buffer chip;

and the power supply negative GND signal of the RS485 bus is respectively and electrically connected with the GND signal of the MCU, the RS485 chip and the tri-state buffer chip.

Further, the RX signal of the MCU is electrically connected with 1 pin of the RS485 chip, the TX signal of the MCU is electrically connected with 4 pins of the RS485 chip, the RE signal of the MCU is electrically connected with 2 pins of the RS485 chip, and the DE signal of the MCU is electrically connected with 3 pins of the RS485 chip.

Further, a sleep _ en signal of the MCU is electrically connected with a pin 1 of the tri-state buffer chip, an RX signal of the MCU is electrically connected with a pin 4 of the tri-state buffer chip, and an A signal of the RS485 bus is electrically connected with a pin 2 of the tri-state buffer chip.

Further, the 7 pins of the RS485 chip are electrically connected with a resistor R3; and the 6 pins of the RS485 chip are electrically connected with a resistor R5.

Furthermore, the power supply + signal of the RS485 bus is respectively and electrically connected with the VCC signal of the MCU, the pin 8 of the RS485 chip and the pin 5 of the tri-state buffer chip.

Furthermore, a power supply negative GND signal of the RS485 bus is respectively and electrically connected with a GND signal of the MCU, a pin 5 of the RS485 chip and a pin 3 of the tri-state buffer chip.

The utility model has the beneficial effects that:

the utility model provides the awakening signal to the equipment when the RS485 chip is dormant by adding the tri-state buffer chip, so that the RS485 bus network has real-time awakening capability on the premise of meeting the requirement of low power consumption, can completely and effectively replace a special chip such as MAX3471, and reduces the cost.

Drawings

Fig. 1 is a block diagram of a low-power wake-up circuit of an electronic remote water meter bus according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a low-power consumption wake-up circuit of an electronic remote water meter bus according to an embodiment of the present invention.

Detailed Description

The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

The embodiments of the present disclosure are described below with specific examples, and other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from the disclosure in the specification. It is to be understood that the described embodiments are merely illustrative of some, and not restrictive, of the embodiments of the disclosure. The disclosure may be embodied or carried out in various other specific embodiments, and various modifications and changes may be made in the details within the description without departing from the spirit of the disclosure. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

In order to have real-time awakening capability and reduce cost on the premise of meeting the requirement of low power consumption, the utility model has the following specific contents.

With reference to fig. 1 and 2, an embodiment of the present invention is a low-power wake-up circuit for an electronic remote water meter bus, including a slave device main control, an RS485 chip, and an RS485 bus, where the slave device main control is integrated with an MCU supporting sleep, and the wake-up circuit is characterized in that: the circuit also comprises a tri-state buffer chip;

the RS485 chip and the tri-state buffer chip are respectively and electrically connected with the MCU, and the other ends of the RS485 chip and the tri-state buffer chip are respectively and electrically connected with the RS485 bus.

The RX signal, the TX signal, the RE signal and the DE signal of the MCU are electrically connected with the RS485 chip;

a sleep _ en signal and an RX signal of the MCU and an A signal of the RS485 bus are electrically connected with a tri-state buffer chip;

the RS485 chip is electrically connected with the resistor R3, and the other end of the R3 is electrically connected with a B signal of an RS485 bus; the RS485 chip is electrically connected with the resistor R5, and the other end of the R5 is electrically connected with an A signal of the RS485 bus;

the power supply + signal of the RS485 bus is respectively and electrically connected with a VCC signal of the MCU, an RS485 chip and a tri-state buffer chip;

and the power supply negative GND signal of the RS485 bus is respectively and electrically connected with the GND signal of the MCU, the RS485 chip and the tri-state buffer chip.

The RX signal of the MCU is electrically connected with 1 pin of the RS485 chip, the TX signal of the MCU is electrically connected with 4 pins of the RS485 chip, the RE signal of the MCU is electrically connected with 2 pins of the RS485 chip, and the DE signal of the MCU is electrically connected with 3 pins of the RS485 chip.

And a sleep _ en signal of the MCU is electrically connected with a pin 1 of the tri-state buffer chip, an RX signal of the MCU is electrically connected with a pin 4 of the tri-state buffer chip, and an A signal of the RS485 bus is electrically connected with a pin 2 of the tri-state buffer chip.

The 7 pins of the RS485 chip are electrically connected with a resistor R3; and the 6 pins of the RS485 chip are electrically connected with a resistor R5.

And the power supply + signal of the RS485 bus is respectively and electrically connected with the VCC signal of the MCU, the 8 pins of the RS485 chip and the 5 pins of the tri-state buffer chip.

And a power supply negative GND signal of the RS485 bus is respectively and electrically connected with a GND signal of the MCU, a pin 5 of the RS485 chip and a pin 3 of the tri-state buffer chip.

The specific work flow is as follows:

the RS485 bus supplies power to the MCU, the RS485 chip and the tri-state buffer chip through a power supply + signal and a power supply negative GND signal respectively.

After the MCU works, the sleep _ en signal of the MCU is controlled to set the pin 1 of the tri-state buffer chip high, so that the change of the pin 2 signal of the tri-state buffer chip can not be transmitted to the pin 4 of the tri-state buffer chip, and the RE and DE signals of the MCU are controlled to be set low, so that the RS485 chip works in a receiving mode.

At the moment, the RS485 bus passes through the A and B signal lines through R3 and R5, and is processed by the RS485 chip through pins 7 and 6, then is sent to the MCU for processing through an RX signal line through pin 1 of the RS485 chip.

And after the MCU processes the command of the RS485 bus, the MCU enters a sleep mode. Before the MCU enters the sleep mode, the RE signal of the MCU is controlled to be set high, and the DE signal of the MCU is controlled to be set low, so that the RS485 chip works in the sleep mode. And the MCU asserts pin 1 of the tri-state buffer chip low via the sleep _ en signal. At this time, the 2-pin signal change of the tri-state buffer chip can be transmitted to the 4 pins of the tri-state buffer chip and transmitted to the MCU through the RX signal. Therefore, after the MCU is in sleep, the RS485 chip also enters a sleep mode, and the power consumption of the tri-state buffer chip is very low, so that the aim of low power consumption is fulfilled.

At this time, if the level of the signal line of the RS485 bus a changes, the level-changed signal is transmitted to the 2 nd pin of the tri-state buffer through the signal line a, the 4 th pin of the tri-state buffer, and the RX signal line is transmitted to the MCU. The MCU transitions from the sleep state to the active state upon receiving a RX signal change.

After the MCU is converted into a working state from a sleep state, the sleep _ en signal of the MCU is controlled to be higher than the pin 1 of the three-state buffer chip, so that the change of the pin 2 signal of the three-state buffer chip cannot be transmitted to the pin 4 of the three-state buffer chip, and the RE signal and the DE signal of the MCU are controlled to be lower, so that the RS485 chip works in a receiving mode. Therefore, the low-power consumption wake-up circuit of the electronic remote water meter bus is completed.

The above description is for the purpose of illustrating embodiments of the utility model and is not intended to limit the utility model, and it will be apparent to those skilled in the art that any modification, equivalent replacement, or improvement made without departing from the spirit and principle of the utility model shall fall within the protection scope of the utility model.

Claims (1)

1. The utility model provides an electron teletransmission water gauge bus low-power consumption awakening circuit, includes slave unit master control, RS485 chip, RS485 bus, the slave unit master control integration has the MCU that supports dormancy, its characterized in that: the circuit also comprises a tri-state buffer chip;

the RS485 chip and the tri-state buffer chip are respectively and electrically connected with the MCU, and the other ends of the RS485 chip and the tri-state buffer chip are respectively and electrically connected with an RS485 bus;

the RX signal, the TX signal, the RE signal and the DE signal of the MCU are electrically connected with the RS485 chip;

a sleep _ en signal and an RX signal of the MCU and an A signal of the RS485 bus are electrically connected with a tri-state buffer chip;

the RS485 chip is electrically connected with the resistor R3, and the other end of the R3 is electrically connected with a B signal of an RS485 bus; the RS485 chip is electrically connected with the resistor R5, and the other end of the R5 is electrically connected with an A signal of the RS485 bus;

the power supply + signal of the RS485 bus is respectively and electrically connected with a VCC signal of the MCU, an RS485 chip and a tri-state buffer chip;

the power supply negative GND signal of the RS485 bus is respectively and electrically connected with the GND signal of the MCU, the RS485 chip and the tri-state buffer chip;

an RX signal of the MCU is electrically connected with a pin 1 of the RS485 chip, a TX signal of the MCU is electrically connected with a pin 4 of the RS485 chip, an RE signal of the MCU is electrically connected with a pin 2 of the RS485 chip, and a DE signal of the MCU is electrically connected with a pin 3 of the RS485 chip;

a sleep _ en signal of the MCU is electrically connected with a pin 1 of the tri-state buffer chip, an RX signal of the MCU is electrically connected with a pin 4 of the tri-state buffer chip, and an A signal of the RS485 bus is electrically connected with a pin 2 of the tri-state buffer chip;

the 7 pins of the RS485 chip are electrically connected with a resistor R3; the 6 pins of the RS485 chip are electrically connected with a resistor R5;

the power supply + signal of the RS485 bus is respectively and electrically connected with a VCC signal of the MCU, an 8 pin of the RS485 chip and a 5 pin of the tri-state buffer chip;

and a power supply negative GND signal of the RS485 bus is respectively and electrically connected with a GND signal of the MCU, a pin 5 of the RS485 chip and a pin 3 of the tri-state buffer chip.

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