CN211046925U - Concentrator - Google Patents

Abstract

The utility model relates to the technical field of the internet of things, and discloses a concentrator, which comprises a ZigBee chip, a serial port level conversion circuit, an NB-IoT chip, a singlechip and a battery circuit; the ZigBee chip is electrically connected with the NB-IoT chip through a serial port level conversion circuit, the ZigBee chip is also electrically connected with the single chip microcomputer, and the ZigBee chip, the single chip microcomputer and the NB-IoT chip are respectively and electrically connected with the battery circuit. The utility model discloses have low-cost, high reliability, simple to operate's technological effect.

Description

Concentrator

Technical Field

The utility model relates to a technical field of the thing networking, concretely relates to concentrator.

Background

The existing concentrator adopts commercial power supply, is inconvenient to install and wire, is easily influenced by lightning stroke, has poor signals in thunderstorm weather, influences signal transmission, can only avoid the influence of the lightning stroke by increasing a lightning protection device, but the cost of the concentrator can be greatly increased, and the concentrator is influenced to be popularized and used on a large scale.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome above-mentioned technique not enough, provide a concentrator, solve among the prior art concentrator installation inconvenient, with high costs, the technical problem that the reliability is low.

In order to achieve the technical purpose, the technical scheme of the utility model provides a concentrator, which comprises a ZigBee chip, a serial port level conversion circuit, an NB-IoT chip, a singlechip and a battery circuit; the ZigBee chip is electrically connected with the NB-IoT chip through a serial port level conversion circuit, the ZigBee chip is also electrically connected with the single chip microcomputer, and the ZigBee chip, the single chip microcomputer and the NB-IoT chip are respectively and electrically connected with the battery circuit.

Compared with the prior art, the beneficial effects of the utility model include: the utility model provides a concentrator adopts the battery circuit to supply power, owing to do not need commercial power supply, consequently does not have thunderbolt potential safety hazard, and the reliability is high, and thunderstorm weather can not influence the transmission of signal, therefore need not set up lightning protection device for the cost descends by a wide margin. Meanwhile, the utility model does not need commercial power supply, so the installation has no more limit and the installation is convenient.

Drawings

Fig. 1 is a schematic circuit diagram of an embodiment of a concentrator according to the present invention;

FIG. 2 is a circuit diagram of a single chip microcomputer and a battery circuit according to the present invention;

FIG. 3 is a circuit diagram of a ZigBee chip in the utility model;

fig. 4 is a circuit diagram of the NB-IoT chip and the serial port level shift circuit according to the present invention.

Reference numerals:

11. ZigBee chip, 12, serial port level conversion circuit, 13, NB-IoT chip, 14, singlechip, 15, battery circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1:

as shown in fig. 1, a concentrator provided in embodiment 1 of the present invention includes a ZigBee chip 11, a serial port level shift circuit 12, an NB-IoT chip 13, a single chip microcomputer 14, and a battery circuit 15;

the ZigBee chip 11 is electrically connected with the NB-IoT chip 13 through a serial port level conversion circuit 12, the ZigBee chip 11 is also electrically connected with the single chip microcomputer 14, and the ZigBee chip 11, the single chip microcomputer 14 and the NB-IoT chip 13 are respectively electrically connected with the battery circuit 15.

The concentrator comprises a ZigBee chip 11 for realizing ZigBee transmission and an NB-IoT chip 13 for realizing NB-IoT transmission, wherein the ZigBee chip 11 is used for collecting data, and the NB-IoT chip 13 is used for uploading the data to a server to realize the function of centralized data transmission. The single chip microcomputer 14 is used for receiving the data collected by the ZigBee chip 11 and providing a sleep clock for the ZigBee chip 11 to realize sleep of the ZigBee chip 11. The ZigBee chip 11, the single chip microcomputer 14 and the NB-IoT chip 13 are all powered by the battery circuit 15, and mains supply is not needed, so that lightning safety hidden dangers are avoided, reliability is high, thunderstorm weather does not affect signal transmission, a lightning protection device is not needed, and cost is greatly reduced. Meanwhile, the concentrator does not need to be powered by mains supply, so that the installation is not more limited, and the concentrator can be hung on a wall or a tree.

Specifically, the model of the ZigBee chip 11 is CC2530, the model of the NB-IoT chip 13 is BC26, the battery circuit 15 is powered by a 3.6V lithium battery, the model of the single chip microcomputer 14 is MSP430, and the serial port level conversion circuit 12 is required because the serial port level of the NB-IoT chip 13 is only 1.8V. The single chip microcomputer 14 provides a sleep clock for the ZigBee chip 11, the sleep clock can be up to 6 hours, for example, the data can be uploaded for 4 times every day, the working time of uploading the data each time is not more than 10 seconds, the rest time is in a sleep state, the sleep current is within 20uA, the average working current is 300mA, and the capacity of a single-section disposable 3.6V lithium battery is 1500mAH, and the single-section disposable 3.6V lithium battery can work for three to five years.

The utility model discloses have low-cost, high reliability and simple to operate's technological effect.

Preferably, as shown in fig. 2, the single chip microcomputer 14 is of a model MSP430, a Vcc pin of the single chip microcomputer 14 is electrically connected to the battery circuit 15, the pin P1.0, the pin P1.1, the pin P1.2, the pin P1.3, the pin P1.4, the pin P1.5 and the pin P1.6 of the singlechip 14 are respectively electrically connected with the ZigBee chip 11, the Vss pin of the single chip microcomputer 14 is grounded, the XIN pin of the single chip microcomputer 14 is electrically connected with the XOUT pin of the single chip microcomputer 14 through a crystal oscillator Y1, the TEST pin and the RST pin of the single chip 14 are electrically connected to the battery circuit 15 through a connector J1, the RST pin of the single chip 14 is electrically connected to the battery circuit 15 through a resistor R4, and is grounded through a capacitor C2, the pin P1.7 of the single chip microcomputer 14 is electrically connected with the cathode of a diode D3, and the anode of the diode D3 is electrically connected with the battery circuit 15 through a resistor R3.

Preferably, as shown in fig. 2, the battery circuit 15 includes a battery BT1, a battery BT2, a switch S1, a capacitor C1, and a capacitor C36;

the positive electrode of the battery BT1 is electrically connected with the positive electrode of the battery BT2 and is respectively electrically connected with the single chip microcomputer 14 and the ZigBee chip 11, the negative electrode of the battery BT1 is electrically connected with the negative electrode of the battery BT2 and is grounded through the switch S1, the positive electrode of the battery BT1 is grounded through the capacitor C1, and the capacitor C36 is connected with the capacitor C1 in parallel.

Preferably, as shown in fig. 3, the model of the ZigBee chip 11 is CC2530, the DVDD pin, the AVDD _ DREG pin, the AVDD5/AVDD _ SOC pin, the AVDD3 pin, the AVDD2 pin, the AVDD1 pin, the AVDD4 pin, and the AVDD _ GUARD pin of the ZigBee chip 11 are all electrically connected to the battery circuit 15, the DVDD pin of the ZigBee chip 11 is grounded through a capacitor C4, the AVDD _ DREG pin of the ZigBee chip 11 is grounded through a capacitor C5, the AVDD5/AVDD _ SOC pin of the ZigBee chip 11 is grounded through a capacitor C6, the AVDD3 pin of the ZigBee chip 11 is grounded through a capacitor C7, the AVDD2 pin of the ZigBee chip 11 is grounded through a capacitor C8, the capacitor C9 is connected in parallel to the capacitor C8, the AVDD _ GUARD pin of the ZigBee chip 11 is grounded through a capacitor C10, and the capacitor C11 is connected in parallel to the capacitor C10;

the DGND _ USB pin, the USB _ M pin, the USB _ P pin and the DVDD _ USB pin of the ZigBee chip 11 are all grounded;

the pin P2_0 of the ZigBee chip 11 is electrically connected to the single chip 14, the pin P2_1 and the pin P2_2 of the ZigBee chip 11 are electrically connected to the single chip 14 through the connector J2, respectively, the pin P1_0 of the ZigBee chip 11 is electrically connected to the cathode of the diode D1, the anode of the diode D1 is electrically connected to the battery circuit 15 through the resistor R1, the pin P1_1 of the ZigBee chip 11 is electrically connected to the cathode of the diode D2, the anode of the diode D2 is electrically connected to the battery circuit 15 through the resistor R2, the pin P1_4 and the pin P1_5 of the ZigBee chip 11 are electrically connected to the NB-IoT chip 13, the pin P1_7, the pin P0_0, the pin P0_1 and the pin P0_2 of the ZigBee chip 11 are electrically connected to the pin P0_3 of the triode 11 is electrically connected to the base of the Q67 2 through the resistor R7, the emitter of the triode Q2 is electrically connected with the base of the triode Q2 through a resistor R8, the collector of the triode Q2 is electrically connected with the NB-IoT chip 13, the pin P0_4 and the pin P0_5 of the ZigBee chip 11 are electrically connected to the battery circuit 15 through connectors Com1 respectively, the P0_6 pin of the ZigBee chip 11 is electrically connected with the battery circuit 15 through a switch S3, and is electrically connected with a pin P0_7 of the ZigBee chip 11 through a resistor R0, the pin P0_7 of the ZigBee chip 11 is electrically connected with the battery circuit 15 through a switch S2, the pin P0_7 of the ZigBee chip 11 is electrically connected with the connector P0, and is electrically connected with the single chip 14 through the connector P0, the RESET _ N pin of the ZigBee chip 11 is electrically connected with the battery circuit 15 through a resistor R5, the ZigBee chip 11 is grounded through a capacitor C3, and a RESET _ N pin is electrically connected with the singlechip 14 through the connector J2;

an RF _ P pin of the ZigBee chip 11 is electrically connected with an RF _ N pin of the ZigBee chip 11 sequentially through a capacitor C12, an inductor L1 and a capacitor C13, a capacitor C14 is connected with an inductor L3 in series and then connected with the inductor L1 in parallel, a common end of the capacitor C12 and the inductor L1 is grounded through an inductor L2, a common end of the capacitor C13 and the inductor L1 is grounded through a capacitor C15, a common end of the capacitor C14 and the inductor L3 is grounded through a capacitor C16 and sequentially connected with a capacitor C17 and a capacitor C18, and a common end of the capacitor C17 and the capacitor C18 is grounded through an antenna ANT;

the XOSC32M _ Q1 pin of the ZigBee chip 11 is electrically connected with the XOSC32M _ Q2 pin of the ZigBee chip 11 through a crystal oscillator Y2, a capacitor C21 is connected in series with a capacitor C20 and then connected in parallel with the crystal oscillator Y2, the common end of the capacitor C21 and the capacitor C20 is grounded, the DCOUP L pin of the ZigBee chip 11 is grounded through a capacitor C19, the RBIAS pin of the ZigBee chip 11 is grounded through a resistor R6, and the GND pin of the ZigBee chip 11 is grounded.

Specifically, CC2530 has three different sleep modes PM1, PM2, and PM3, with PM3 mode being the lowest power consumption. When CC2530 operates in PM1 and PM2 modes, CC2530 in a sleep state can be woken up by using a timer interrupt, but the sleep time is only 511 seconds, which is far from meeting the technical requirement of long sleep time (such as 6 hours); therefore, the preferred embodiment selects the PM3 mode, and when the CC2530 is in the deep sleep mode, i.e., the PM3 mode, the CC can only be waken up by an external interrupt or reset mode, so that the CC needs to be waken up by externally connecting a single chip microcomputer 14, and the externally connected single chip microcomputer 14 plays a role of "sleep nanny", thereby reducing the system power consumption as much as possible. The external singlechip 14 preferably has extremely low power consumption in a sleep mode, and the MSP430 singlechip 14 is selected in the embodiment.

CC2530 issues a sleep timing signal to MSP430 through P0_0 pin, and then CC2530 enters a sleep state, which MSP430 receives by setting P1_0 pin to interrupt. The stop of sleep is achieved by pin MSP 430P 1_0 sending a Reset signal to Reset pin Reset of CC 2530.

Preferably, as shown in fig. 4, the NB-IoT chip 13 is of a type BC26, VBAT _ RF pin and VBAT _ BB pin of the NB-IoT chip 13 are both electrically connected to the battery circuit 15, VBAT _ RF pin of the NB-IoT chip 13 is electrically connected to cathode of a voltage regulator tube D6, anode of the voltage regulator tube D6 is grounded, GND pin of the NB-IoT chip 13 is grounded, PWRKEY pin of the NB-IoT chip 13 is electrically connected to the ZigBee chip 11 and to cathode of a voltage regulator tube D11, and anode of the voltage regulator tube D11 is grounded;

the SIM _ GND pin of the NB-IoT chip 13 is electrically connected with the Vss pin of a SIM card, the Vss pin of the SIM card is electrically connected with the Vdd pin of the SIM card through a capacitor C28, the Vdd pin of the SIM card is grounded through a capacitor C24, the SIM _ DATA pin of the NB-IoT chip 13 is electrically connected with the I/O pin of the SIM card through a resistor R10, the I/O pin of the SIM card is grounded through a capacitor C26, the SIM _ RST pin of the NB-IoT chip 13 is electrically connected with the RST pin of the SIM card through a resistor R9, the RST pin of the SIM card is grounded through a capacitor C25, the SIM _ C L K pin of the NB-IoT chip 13 is electrically connected with the C L K pin of the SIM card through a resistor R11, the C L K pin of the SIM card is grounded through a capacitor C27, the SIM _ GND pin of the NB-IoT chip 13 is electrically connected with the SIM _ VDD pin of the NB-IoT chip 13 through a resistor R17;

the RESET pin of the NB-IoT chip 13 is electrically connected with the cathode of a voltage regulator tube D5, the anode of the voltage regulator tube D5 is grounded, the NET L IGHT pin of the NB-IoT chip 13 is electrically connected with the base of a triode Q1 through a resistor R14, the emitter of the triode Q1 is grounded, the collector of the triode Q1 is electrically connected with the cathode of a diode D4, and the anode of the diode D4 is electrically connected with the battery circuit 15 through a resistor R15;

the RXD pin and the TXD pin of the NB-IoT chip 13 are respectively and electrically connected with the ZigBee chip 11 through the serial port level conversion circuit 12; the VDD _ EXT pin of the NB-IoT chip 13 is grounded through a capacitor C35, the RF _ ANT pin of the NB-IoT chip 13 is grounded through a capacitor C34, and is grounded through a resistor R16 and a capacitor C33 in sequence, and the antenna E1 is connected in parallel with the capacitor C33.

Preferably, as shown in fig. 4, the serial port level shift circuit 12 includes a transistor Q4, a resistor R13, a resistor R18, a capacitor C23, a transistor Q3, a resistor R12, a resistor R19, and a capacitor C22

A collector of the triode Q4 is electrically connected with an RXD pin of the NB-IoT chip 13, a collector of the triode Q4 is electrically connected with a base of the triode Q4 sequentially through the resistor R18 and the resistor R13, the capacitor C23 is connected in parallel with the resistor R13, and an emitter of the triode Q4 is electrically connected with the ZigBee chip 11;

an emitter of the triode Q3 is electrically connected with a TXD pin of the NB-IoT chip 13, a base of the triode Q3 is electrically connected with a VDD _ EXT pin of the NB-IoT chip 13 through a resistor R12, the capacitor C22 is connected in parallel with the resistor R12, and a collector of the triode Q3 is electrically connected with the ZigBee chip 11 and is electrically connected with the battery circuit 15 through the resistor R19.

Specifically, the pins of the same name in fig. 2, 3, and 4 are electrically connected to each other.

The above description of the present invention does not limit the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the scope of the claims of the present invention.

Claims (5)

1. A concentrator is characterized by comprising a ZigBee chip, a serial port level conversion circuit, an NB-IoT chip, a singlechip and a battery circuit;

the ZigBee chip is electrically connected with the NB-IoT chip through a serial port level conversion circuit, the ZigBee chip is also electrically connected with the single chip microcomputer, and the ZigBee chip, the single chip microcomputer and the NB-IoT chip are respectively and electrically connected with the battery circuit;

the model of the ZigBee chip is CC2530, the ZigBee chip adopts a PM3 mode, and the single chip wakes up the ZigBee chip through external interruption or reset;

the battery circuit comprises a battery BT1, a battery BT2, a switch S1, a capacitor C1 and a capacitor C36;

the positive electrode of the battery BT1 is electrically connected with the positive electrode of the battery BT2 and is respectively electrically connected with the single chip microcomputer and the ZigBee chip, the negative electrode of the battery BT1 is electrically connected with the negative electrode of the battery BT2 and is grounded through the switch S1, the positive electrode of the battery BT1 is grounded through the capacitor C1, and the capacitor C36 is connected with the capacitor C1 in parallel.

2. The concentrator of claim 1, wherein the single chip microcomputer is of a model MSP430, a Vcc pin of the single chip microcomputer is electrically connected with the battery circuit, a P1.0 pin, a P1.1 pin, a P1.2 pin, a P1.3 pin, a P1.4 pin, a P1.5 pin and a P1.6 pin of the single chip microcomputer are respectively electrically connected with the ZigBee chip, a Vss pin of the single chip microcomputer is grounded, a XIN pin of the single chip microcomputer is electrically connected with an XOUT pin of the single chip microcomputer through a crystal oscillator Y1, a TEST pin and a RST pin of the single chip microcomputer are respectively electrically connected with the battery circuit through a connector J1, a RST pin of the single chip microcomputer is electrically connected with the battery circuit through a resistor R4 and is grounded through a capacitor C2, a P1.7 pin of the single chip microcomputer is electrically connected with a cathode of a diode D3, and an anode of the diode D3 is electrically connected with the battery circuit through a resistor R3.

3. The concentrator according to claim 1, wherein the ZigBee chip is of a type CC2530, the DVDD pin, the AVDD _ DREG pin, the AVDD5/AVDD _ SOC pin, the AVDD3 pin, the AVDD2 pin, the AVDD1 pin, the AVDD4 pin, and the AVDD _ GUARD pin of the ZigBee chip are electrically connected to the battery circuit, the DVDD pin of the ZigBee chip is grounded through a capacitor C4, the AVDD _ DREG pin of the ZigBee chip is grounded through a capacitor C5, the AVDD5/AVDD _ SOC pin of the ZigBee chip is grounded through a capacitor C6, the AVDD3 pin of the ZigBee chip is grounded through a capacitor C7, the AVDD2 pin of the ZigBee chip is grounded through a capacitor C8, the capacitor C9 is connected in parallel to the capacitor C8, the AVDD _ GUARD pin of the ZigBee chip is grounded through a capacitor C10, and the capacitor C11 is connected in parallel to the capacitor C10;

a DGND _ USB pin, a USB _ M pin, a USB _ P pin and a DVDD _ USB pin of the ZigBee chip are all grounded;

the pin P2_0 of the ZigBee chip is electrically connected with the single chip microcomputer, the pin P2_1 and the pin P2_2 of the ZigBee chip are electrically connected with the single chip microcomputer through a connector J2 respectively, the pin P1_0 of the ZigBee chip is electrically connected with the cathode of a diode D1, the anode of the diode D1 is electrically connected with the battery circuit through a resistor R1, the pin P1_1 of the ZigBee chip is electrically connected with the cathode of a diode D2, the anode of the diode D2 is electrically connected with the battery circuit through a resistor R2, the pin P1_4 and the pin P1_5 of the ZigBee chip are electrically connected with the NB-IoT chip respectively, the pin P1_7, the pin P0_0, the pin P0_1 and the pin P0_2 of the ZigBee chip are electrically connected with the single chip microcomputer respectively, and the pin P0_3 of the ZigBee chip is electrically connected with the base of a triode Q2 through a resistor R7, the emitter of the triode Q2 is electrically connected with the base of the triode Q2 through a resistor R8, the collector of the triode Q2 is electrically connected with the NB-IoT chip, the pin P0_4 and the pin P0_5 of the ZigBee chip are respectively and electrically connected with the battery circuit through a connector Com1, the pin P0_6 of the ZigBee chip is electrically connected with the battery circuit through a switch S3, and is electrically connected with the P0_7 pin of the ZigBee chip through a resistor R0, the P0_7 pin of the ZigBee chip is electrically connected with the battery circuit through a switch S2, the P0_7 pin of the ZigBee chip is electrically connected with a connector P0, and is electrically connected with the single chip microcomputer through the connector P0, a RESET _ N pin of the ZigBee chip is electrically connected with the battery circuit through a resistor R5, the ZigBee chip is grounded through a capacitor C3, and a RESET _ N pin of the ZigBee chip is electrically connected with the single chip microcomputer through the connector J2;

an RF _ P pin of the ZigBee chip is electrically connected with an RF _ N pin of the ZigBee chip sequentially through a capacitor C12, an inductor L1 and a capacitor C13, a capacitor C14 is connected with an inductor L3 in series and then connected with the inductor L1 in parallel, a common end of the capacitor C12 and the inductor L1 is grounded through an inductor L2, a common end of the capacitor C13 and the inductor L1 is grounded through a capacitor C15, a common end of the capacitor C14 and the inductor L3 is grounded through a capacitor C16 and sequentially connected with a capacitor C17 and a capacitor C18, and a common end of the capacitor C17 and the capacitor C18 is grounded through an antenna ANT;

an XOSC32M _ Q1 pin of the ZigBee chip is electrically connected with an XOSC32M _ Q2 pin of the ZigBee chip through a crystal oscillator Y2, a capacitor C21 is connected with a capacitor C20 in series and then connected with the crystal oscillator Y2 in parallel, the common end of the capacitor C21 and the capacitor C20 is grounded, a DCOUP L pin of the ZigBee chip is grounded through a capacitor C19, an RBIAS pin of the ZigBee chip is grounded through a resistor R6, and a GND pin of the ZigBee chip is grounded.

4. The concentrator of claim 1, wherein the NB-IoT chip is of a model BC26, VBAT _ RF pin and VBAT _ BB pin of the NB-IoT chip are both electrically connected to the battery circuit, VBAT _ RF pin of the NB-IoT chip is electrically connected to cathode of a voltage regulator tube D6, anode of the voltage regulator tube D6 is grounded, GND pin of the NB-IoT chip is all grounded, PWRKEY pin of the NB-IoT chip is electrically connected to the ZigBee chip and to cathode of a voltage regulator tube D11, anode of the voltage regulator tube D11 is grounded;

the SIM _ GND pin of the NB-IoT chip is electrically connected with the Vss pin of a SIM card, the Vss pin of the SIM card is electrically connected with the Vdd pin of the SIM card through a capacitor C28, the Vdd pin of the SIM card is grounded through a capacitor C24, the SIM _ DATA pin of the NB-IoT chip is electrically connected with the I/O pin of the SIM card through a resistor R10, the I/O pin of the SIM card is grounded through a capacitor C26, the SIM _ RST pin of the NB-IoT chip is electrically connected with the RST pin of the SIM card through a resistor R9, the RST pin of the SIM card is grounded through a capacitor C25, the SIM _ C L K pin of the NB-IoT chip is electrically connected with the C L K pin of the SIM card through a resistor R11, the C L K pin of the SIM card is grounded through a capacitor C27, the SIM _ GND pin of the NB-IoT chip is electrically connected with the NB-IoT pin through a resistor R17, and the SIM _ GND pin of the NB-IoT chip is electrically connected with the Vdd pin;

the RESET pin of the NB-IoT chip is electrically connected with the cathode of a voltage regulator tube D5, the anode of the voltage regulator tube D5 is grounded, the NET L IGHT pin of the NB-IoT chip is electrically connected with the base electrode of a triode Q1 through a resistor R14, the emitter of the triode Q1 is grounded, the collector of the triode Q1 is electrically connected with the cathode of a diode D4, and the anode of the diode D4 is electrically connected with the battery circuit through a resistor R15;

the RXD pin and the TXD pin of the NB-IoT chip are respectively and electrically connected with the ZigBee chip through the serial port level conversion circuit; the VDD _ EXT pin of the NB-IoT chip is grounded through a capacitor C35, the RF _ ANT pin of the NB-IoT chip is grounded through a capacitor C34 and is grounded through a resistor R16 and a capacitor C33 in sequence, and an antenna E1 is connected with the capacitor C33 in parallel.

5. The concentrator of claim 4, wherein the serial port level shift circuit comprises a transistor Q4, a resistor R13, a resistor R18, a capacitor C23, a transistor Q3, a resistor R12, a resistor R19, a capacitor C22

A collector of the triode Q4 is electrically connected with an RXD pin of the NB-IoT chip, a collector of the triode Q4 is electrically connected with a base of the triode Q4 sequentially through the resistor R18 and the resistor R13, the capacitor C23 is connected with the resistor R13 in parallel, and an emitter of the triode Q4 is electrically connected with the ZigBee chip;

an emitter of the triode Q3 is electrically connected with a TXD pin of the NB-IoT chip, a base of the triode Q3 is electrically connected with a VDD _ EXT pin of the NB-IoT chip through a resistor R12, the capacitor C22 is connected with the resistor R12 in parallel, and a collector of the triode Q3 is electrically connected with the ZigBee chip and is electrically connected with the battery circuit through the resistor R19.

Images