A battery-free thermometer and hygrometer device and its control method

Abstract

The present invention discloses a battery-free thermometer and hygrometer device and its control method. The device includes an energy harvesting system, a timing trigger system, and a thermometer and hygrometer system. The energy harvesting system includes a light energy harvesting converter, a first LX01 voltage detection circuit, an LX02 energy harvesting circuit, a first power management module, a pull-up resistor R1, and a super capacitor C1. The light energy harvesting converter is connected to the input end V of the first LX01 voltage detection circuit. in The output V of the first LX01 voltage detection circuit OD1 The output V of the first LX01 voltage detection circuit OD1 is connected to the enable end of the LX02 energy harvesting circuit. The output of the light energy harvesting converter is simultaneously connected to the input of the LX02 energy harvesting circuit. The output of the LX02 energy harvesting circuit is connected to the input of the first power management module. The output voltage of the first power management module powers the timing trigger system, and the voltage output end of the timing trigger system powers the thermometer and hygrometer system. Through zero-power continuous voltage detection technology, the power consumption of the energy harvesting system and the load is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic device design, and particularly relates to a battery-free thermometer and hygrometer device and its control method. Background Art

[0002] The temperature and humidity of the environment have a significant impact on production and life. Therefore, the measurement of temperature and humidity is extremely important. A thermometer and hygrometer is an electronic device that can measure temperature and humidity through a sensor at a certain time interval. Existing thermometers and hygrometers require batteries for power supply, and the standby power consumption is relatively large, accounting for more than half of the total power consumption. The replacement of batteries often reduces the user experience. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a battery-free thermometer and hygrometer device and its control method. Through a zero-power continuous voltage detection technology, the present invention reduces the power consumption of both the energy harvesting system and the load, enabling the light energy collected by the system to meet the load requirements, avoiding the inconvenience brought to users by battery replacement, and greatly improving the convenience of use.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a battery-free thermometer and hygrometer device, including an energy harvesting system, a timing trigger system, and a thermometer and hygrometer system; wherein, the energy harvesting system includes a light energy harvesting converter, a first LX01 voltage detection circuit, an LX02 energy harvesting circuit, a first power management module, a pull-up resistor R1, and a super capacitor C1; the light energy harvesting converter is connected to the input end V of the first LX01 voltage detection circuit in is connected, the output V of the first LX01 voltage detection circuit OD1 is connected to VBAT through the pull-up resistor R1, and the output V of the first LX01 voltage detection circuit OD1 is connected to the enable end of the LX02 energy harvesting circuit; the output of the light energy harvesting converter is simultaneously connected to the input of the LX02 energy harvesting circuit, the output of the LX02 energy harvesting circuit is VBAT, the output VBAT of the LX02 energy harvesting circuit is connected to the energy storage super capacitor C1, and the output VBAT of the LX02 energy harvesting circuit is simultaneously connected to the input of the first power management module. The output voltage of the first power management module powers the timing trigger system, and the voltage output end of the timing trigger system powers the thermometer and hygrometer system.

[0005] The timing trigger system includes an LX04 ultra-low power oscillator, a logic gate, a frequency divider, a MOS switch, an RC delay circuit, and a second power management module; the output of the oscillator LX04 is connected to the input of the frequency divider, and the two output ends of the frequency divider are respectively connected to the logic gate and the RC delay circuit; the positive electrode of the capacitor C2 is connected to the input of the logic gate, and the output of the logic gate is connected to the input end V of the second LX01 voltage detection circuitin Connection;

[0006] The output V of the second LX01 voltage detection circuit OD2 Is connected to the gate of the switching NMOS - Q1 through the pull - up resistor R2. The drain of the switching NMOS - Q1 is connected to the output VBAT of the LX02 energy harvesting circuit, and the source of the switching NMOS - Q1 is connected to the input V of the second power management module in Is connected. The output V of the second power management module DD2 Provides a stable voltage for the load thermometer system, and the negative electrode of the capacitor C2 is grounded; the grounding terminal of the LX01 voltage detection circuit is grounded, and the negative electrode of the supercapacitor C1 is grounded; the two output terminals of the frequency divider are the first output a and the second output b respectively, and the logic of the first output a and the second output b is opposite. Among them, the first output a is connected to the input interface a of the logic gate, and the second output b is connected to the RC delay circuit; the first LX01 voltage detection circuit is the same as the second LX01 voltage detection circuit, and the logic gate uses a NOR gate; the power supply interfaces of the oscillator, the frequency divider, and the logic gate are all connected to the voltage output V in the energy harvesting system OD1 Connected.

[0007] The thermometer system includes a signal processing and control unit, a low - power thermometer, and a paper screen. Among them, the temperature and humidity sensor is connected to the input end of the signal processing and control module, and the output end of the signal processing and control module is connected to the paper screen.

[0008] The output end of the signal processing and control module is connected with a ZigBee module.

[0009] The optical energy harvesting converter uses a solar panel.

[0010] The first LX01 voltage detection circuit includes a high - voltage monitoring circuit, a medium - voltage monitoring circuit, and a low - voltage monitoring circuit. The V of the high - voltage monitoring circuit O(H) Output is connected to the control end of the medium - voltage monitoring single - path. The V of the medium - voltage monitoring circuit O(M) Output is connected to the control end of the low - voltage monitoring circuit. The outputs of the high - voltage monitoring circuit, the medium - voltage monitoring circuit, and the low - voltage monitoring circuit are all connected to the output V of the LX01 voltage monitoring circuit OD1 .

[0011] For the control method of the battery - less thermometer device of the present invention, when the voltage of the input end V in of the first LX01 voltage detection circuit is lower than the threshold V TH of the LX01 voltage detection circuit, the output V OD1 of the first LX01 voltage detection circuit remains low. When the voltage of the input end V in of the first LX01 voltage detection circuit is higher than the threshold V THWhen the output V of the first LX01 voltage detection circuit OD1 converts to a high level and remains so until the voltage at the input V of the first LX01 voltage detection circuit in is lower than the falling threshold V of the LX01 voltage detection circuit TL When there is light indoors, the photo energy harvesting converter board outputs a high voltage, and the voltage exceeds V TH Then the LX02 energy harvesting circuit is enabled. When there is no light indoors, the photo energy harvesting converter outputs a low voltage, and the LX02 energy harvesting circuit enters the shutdown state. The output of the LX02 energy harvesting circuit is VBAT, and VBAT is connected to the super capacitor C1. The positive electrode of the super capacitor C1 is connected to the first power management module, and the output of the first power management module is V DD1 V DD1 powers the timing trigger system; when a high voltage is output in the timing trigger system, the load temperature and humidity meter system is activated, and the temperature and humidity sensor starts to measure the temperature and humidity parameters.

[0012] The temperature and humidity sensor measures the temperature and humidity parameters and transmits the parameters to the signal processing and control module. The signal processing and control module transmits the information to the bound gateway through the ZigBee module; the paper screen displays the corresponding temperature and humidity readings. When the NOR gate outputs a low level during a cycle or when the load temperature and humidity meter system is in the shutdown state, the paper screen still displays the temperature and humidity readings.

[0013] When the output V of the second LX01 voltage detection circuit OD2 outputs high, the switch NMOS-Q1 conducts, and the output voltage VBAT of the LX02 energy harvesting circuit is converted into the voltage required by the load through the second power management module, and the temperature and humidity meter system is activated. When the output V of the second LX01 voltage detection circuit OD2 outputs low, the switch NMOS-Q1 disconnects, the input of the second power management module is 0V, and its output is also 0V. The temperature and humidity meter system is in the shutdown state to remove the static power consumption of the temperature and humidity meter system and the second power management module.

[0014] The frequency divider is used to control the duration of the cycle, which is determined by the number of bits of the frequency divider. The values of the resistor R3 and the capacitor C2 in the RC delay circuit are adjusted to control the duty cycle of the cycle signal, that is, the ratio of the time when the load is activated to the shutdown time.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] The present invention adopts a zero-power continuous voltage detection technology. Through the first LX01 voltage detection circuit, the energy harvesting system can be made to operate only when the energy that can be harvested is greater than the static power consumption of the LX02 energy harvesting circuit itself; reducing the power consumption of the energy harvesting system and the load enables the light energy collected by the system to meet the load requirements, avoiding the inconvenience brought to users by charging or replacing batteries, and greatly enhancing the convenience of use; also, through an ultra-low-power timing trigger system, the thermometer and hygrometer system is awakened at preset intervals. After awakening, the thermometer and hygrometer works for a period of time and then enters the zero-power standby mode again, which not only reduces power consumption but also facilitates use.

[0017] Furthermore, the solar energy harvesting technology is adopted to provide power for the system. Therefore, the system does not require a battery or charging. The system provides Zigbee as the wireless communication method and integrates a display function at the same time.

[0018] Furthermore, when the output of the NOR gate is at a low level in a cycle and the load thermometer and hygrometer system is shut down, the paper screen still has a display, which will not affect the normal reading by the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the system structure of the present invention;

[0020] Figure 2 is a signal control schematic diagram of the LX01 voltage detection circuit in the present invention;

[0021] Figure 3 is a timing diagram of the timing trigger system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] A battery-free thermometer and hygrometer device provided by the present invention includes an energy harvesting system, a timing trigger system, and a thermometer and hygrometer system;

[0023] Among them, the energy harvesting system includes a solar panel, a first LX01 voltage detection circuit, an LX02 energy harvesting circuit, a first power management module, and resistors and capacitors.

[0024] Among them, the solar panel in the energy harvesting system is connected to the input terminal V of the first LX01 voltage detection circuit in is connected, and the output V of the LX01 voltage detection circuit OD1 , the output V of the first LX01 voltage detection circuit OD1 is connected to VBAT through a pull-up resistor R1. The output V of the first LX01 voltage detection circuit OD1It is connected to the enable terminal of the LX02 energy harvesting circuit; the output of the solar panel is simultaneously connected to the input of the LX02 energy harvesting circuit. The output of the LX02 energy harvesting circuit is VBAT. The output VBAT of the LX02 energy harvesting circuit is connected to the energy storage supercapacitor C1, and the energy storage supercapacitor C1 provides energy for other systems. The output VBAT of the LX02 energy harvesting circuit is simultaneously connected to the input of the first power management module, and the output voltage of the first power management module is V DD1 .

[0025] The timing trigger system includes an LX04 ultra-low power oscillator, a logic gate, a frequency divider, a MOS switch, an RC delay circuit, and a second power management module. Among them, the output of the LX04 ultra-low power oscillator is connected to the input of the frequency divider, and the oscillation frequency is adjusted within a large range through the number of bits of the frequency divider. The first output a and the second output b of the frequency divider have opposite logics. Among them, the output a of the frequency divider is connected to the input interface a of the logic gate, the second output b of the frequency divider is connected to the RC delay circuit, the positive electrode of the capacitor C2 is connected to the input interface b of the logic gate, and the output of the logic gate is connected to the input terminal V of the second LX01 voltage detection circuit in is connected; the power supply interfaces of the oscillator, the frequency divider, and the logic gate are all connected to the output V of the first power management module in the energy harvesting system DD1 is connected, and the output V of the second LX01 voltage detection circuit OD2 is connected to the output VBAT of the LX02 energy harvesting circuit through a pull-up resistor R2, and the output V of the LX01 voltage detection circuit OD2 is connected to the gate of the MOS switch NMOS-Q1. The drain of the MOS switch NMOS-Q1 is connected to the output VBAT of the LX02 energy harvesting circuit, and the source of the NMOS-Q1 is connected to the input V of the second power management module in is connected, and the output V of the second power management module DD2 provides a stable voltage for the load thermometer system, and the logic gate uses a NOR gate.

[0026] The thermometer system includes a Zigbee module, a signal processing and control unit, a low-power thermometer, and a paper screen. Among them, the temperature and humidity sensor is connected to the input terminal of the signal processing and control module, and the output terminal of the signal processing and control module is connected to the Zigbee module and the paper screen.

[0027] The thermometer system is woken up by the timing trigger system. In the wake-up state, the temperature and humidity sensor converts the temperature and humidity analog quantities into digital signals and then transmits them to the digital signal processing and control module. This module will control the paper screen to display the corresponding temperature and humidity, and control the Zigbee module to transmit the temperature and humidity information to the bound gateway.

[0028] As an alternative embodiment, the present invention can also provide electrical energy through a wireless energy harvesting system, such as the energy harvesting system described in the patent with the publication number CN212674276U, and is powered by the power management module therein.

[0029] As a preferred embodiment, the LX01 voltage detection circuit of the present invention adopts the voltage detection circuit described in the patent with the patent number ZL201710971531.9. The first LX01 voltage detection circuit includes a high-voltage monitoring circuit, a medium-voltage monitoring circuit, and a low-voltage monitoring circuit. The V O(H) output of the high-voltage monitoring circuit is connected to the control terminal of the medium-voltage monitoring single circuit. The V O(M) output of the medium-voltage monitoring circuit is connected to the control terminal of the low-voltage monitoring circuit. The outputs of the high-voltage monitoring circuit, the medium-voltage monitoring circuit, and the low-voltage monitoring circuit are all connected to the output V OD1 of the LX01 voltage monitoring circuit.

[0030] As Figure 1 shown, the present invention includes an energy harvesting system, a timing trigger system, and a temperature and humidity meter system. The solar panel in the energy harvesting system is connected to the input terminal V in of the first LX01 voltage detection circuit. When the voltage at the input terminal V in of the first LX01 voltage detection circuit is lower than the threshold V TH of the LX01 voltage detection circuit, the output V OD1 of the first LX01 voltage detection circuit remains low. When the voltage at the input terminal V in of the first LX01 voltage detection circuit is higher than the threshold V TH of the LX01 voltage detection circuit, the output V OD1 of the first LX01 voltage detection circuit is converted to high level and remains until the voltage at the input terminal V in of the first LX01 voltage detection circuit is lower than the falling threshold V TL of the LX01 voltage detection circuit. Its signal schematic diagram is as Figure 2 shown. The output V OD1 of the first LX01 voltage detection circuit is connected to the enable terminal En of the LX02 energy harvesting circuit through the pull-up resistor R1. When there is light indoors, the solar panel outputs a high voltage, and the voltage exceeds V TH . The LX02 energy harvesting circuit is enabled. When there is no light indoors, the solar panel outputs a low voltage, and the LX02 energy harvesting circuit enters the shutdown state. Through the first LX01 voltage detection circuit, the function that the energy harvesting system only works when the energy that can be harvested is greater than the static power consumption of the LX02 energy harvesting circuit itself is realized, improving the energy harvesting efficiency. The output of the solar panel is also connected to the input terminal V inConnection: The LX02 energy harvesting circuit adopts maximum power tracking to improve the energy harvesting efficiency. The output of the LX02 energy harvesting circuit is VBAT, which is connected to the supercapacitor C1. The supercapacitor C1 serves as the main energy storage capacitor and is the energy source for other systems. The positive electrode of the supercapacitor C1 is connected to the first power management module, and the output of the first power management module is V DD1 , V DD1 to power the LX04 ultra-low power oscillator NOR gate and frequency divider.

[0031] The timing trigger system can wake up the load thermometer at regular intervals. Compared with the signal processing and control center in the load system that measures temperature and humidity at a certain frequency through a timer, the static power consumption of the timing trigger system is much smaller. Under the power supply condition of 1.2V, the average consumption current is only about 110nA. When the load system is not activated by the timer, the power consumption of the load system is 0. In this way, the power consumption of the load thermometer is greatly reduced. The output of the LX04 ultra-low power oscillator in the timing trigger system is connected to the input of the frequency divider. The output of the LX04 ultra-low power oscillator itself is a square wave of about 50Hz - 1000Hz. The function of the frequency divider is to greatly control the duration of the period, which is determined by the number of bits of the frequency divider. The first output a and the second output b of the frequency divider have opposite logics. Among them, the first output a of the frequency divider is connected to the input interface a of the NOR gate, and the second output b of the frequency divider is connected to the RC delay circuit. The positive electrode of the capacitor C2 is connected to the input interface b of the NOR gate. By adjusting the values of the resistor R3 and the capacitor C2 in the RC delay circuit, the duty cycle of the periodic signal is controlled, that is, the ratio of the time when the load is activated to the downtime. The output of the NOR gate is connected to the input terminal V in of the second LX01 voltage detection circuit. The power supply interfaces of the oscillator, frequency divider, and NOR gate are connected to the output V DD1 of the first power management module in the energy harvesting system. The output V OD2 of the second LX01 voltage detection circuit is connected to the gate of the switch NMOS-Q1 through the pull-up resistor R2. The drain of the switch NMOS-Q1 is connected to the output VBAT of the LX02 energy harvesting circuit, and the source is connected to the input V in of the power management. Since the voltage of VBAT is not adjusted and is not suitable as the power supply for the load, the voltage VBAT is DC-converted through the first power management module to be converted into a power supply suitable for the load wireless switch system. The output V DD2 of the second power management module is connected to the positive electrode of the thermometer system. When the output V OD2The output is high, the switching NMOS - Q1 is turned on, and the output voltage VBAT of the LX02 energy harvesting circuit is converted into the voltage required by the load through the second power management module. The load system (i.e., the temperature and humidity meter system) is activated, and the output V of the second LX01 voltage detection circuit OD2 When the output is low, the switching NMOS - Q1 is turned off, and the power management output V DD2 The output is 0V, and the temperature and humidity meter system is in the shutdown state to remove the standby power consumption of the temperature and humidity meter system.

[0032] Figure 3 is the logic timing diagram of the timing trigger system, showing the output signal of the LX04 ultra - low - power oscillator, the first output a of the frequency divider, the second output b of the frequency divider, whose signals are div_a, div_b respectively, the signal nor of the NOR gate output, and the output signal V of the second LX01 voltage detection circuit OD2 The frequency division ratio of the frequency divider in the present invention is 1 / 8, which divides the signal output by the LX04 ultra - low - power oscillator. The logics of div_b and div_a are opposite. Because the signal div_b passes through the delay circuit composed of the resistor R3 and the capacitor C2, the rising edge and the falling edge will be extended and become gentle, resulting in a high - level pulse of the NOR gate signal nor during the rising edge stage of div_b. The output V of the second LX01 voltage detection circuit OD2 pulls up the high - level voltage of the nor signal through a pull - up resistor, and its logic is consistent with the nor signal.

[0033] The temperature and humidity meter load includes a low - power temperature and humidity sensor, a Zigbee module, a signal processing and control unit, and a paper screen; when the NOR gate in the timing trigger system outputs a high voltage, the load temperature and humidity meter system is activated, and the temperature and humidity meter starts to measure the temperature and humidity parameters and transmits the parameters to the signal processing and control module. This module controls the paper screen to display the corresponding temperature and humidity readings and transmits the information to the bound gateway through the Zigbee module. The paper screen can still have the display function without being powered. Therefore, when the NOR gate outputs a low level in a cycle and the load temperature and humidity meter system is in the shutdown state, the paper screen still has a display and does not affect the normal reading by the user.

Claims

1. A battery-free thermometer and hygrometer device, characterized in that, It includes an energy harvesting system, a timing trigger system, and a temperature and humidity meter system; among them, the energy harvesting system includes a light energy harvesting converter, a first LX01 voltage detection circuit, an LX02 energy harvesting circuit, a first power management module, a pull-up resistor R1, and a supercapacitor C1; the light energy harvesting converter is connected to the input terminal V of the first LX01 voltage detection circuit in is connected, and the output V of the first LX01 voltage detection circuit OD1 is connected to VBAT through the pull-up resistor R1, and the output V of the first LX01 voltage detection circuit OD1 is connected to the enable terminal of the LX02 energy harvesting circuit; the output of the light energy harvesting converter is simultaneously connected to the input of the LX02 energy harvesting circuit, the output of the LX02 energy harvesting circuit is VBAT, the output VBAT of the LX02 energy harvesting circuit is connected to the energy storage supercapacitor C1, the output VBAT of the LX02 energy harvesting circuit is simultaneously connected to the input of the first power management module, the output voltage of the first power management module supplies power to the timing trigger system, and the voltage output terminal of the timing trigger system supplies power to the temperature and humidity meter system; the timing trigger system includes an LX04 ultra-low power oscillator, a logic gate, a frequency divider, a MOS switch, an RC delay circuit, and a second power management module; the output of the oscillator LX04 is connected to the input of the frequency divider, and the two output terminals of the frequency divider are respectively connected to the logic gate and the RC delay circuit; the positive electrode of the capacitor C2 is connected to the input of the logic gate, and the output of the logic gate is connected to the input terminal V of the second LX01 voltage detection circuit in is connected; The output V of the second LX01 voltage detection circuit OD2 is connected to the gate of the switching NMOS - Q1 through the pull - up resistor R2. The drain of the switching NMOS - Q1 is connected to the output VBAT of the LX02 energy harvesting circuit, and the source of the switching NMOS - Q1 is connected to the input V in of the second power management module. The output V DD2 of the second power management module provides a stable voltage for the load temperature and humidity meter system, and the negative electrode of the capacitor C2 is grounded; the ground terminal of the LX01 voltage detection circuit is grounded, and the negative electrode of the super - capacitor C1 is grounded; the two output terminals of the frequency divider are the first output a and the second output b respectively, and the logic of the first output a and the second output b is opposite. Among them, the first output a is connected to the input interface a of the logic gate, and the second output b is connected to the RC delay circuit; the first LX01 voltage detection circuit is the same as the second LX01 voltage detection circuit, and the logic gate uses a NOR gate; the power supply interfaces of the oscillator, the frequency divider, and the logic gate are all connected to the voltage output V OD1 in the energy harvesting system.

2. The battery-free thermometer and hygrometer device according to claim 1, characterized in that, The thermometer and hygrometer system includes a signal processing and control unit, a low-power thermometer and hygrometer, and a paper screen. Among them, the temperature and humidity sensor is connected to the input end of the signal processing and control module, and the output end of the signal processing and control module is connected to the paper screen.

3. The battery-free thermometer and hygrometer device according to claim 1, characterized in that, The output end of the signal processing and control module is connected with a ZigBee module.

4. The battery-free thermometer and hygrometer device according to claim 1, characterized in that, The light energy collection converter uses a solar panel.

5. The battery-free thermometer and hygrometer device according to claim 1, characterized in that, The first LX01 voltage detection circuit includes a high-voltage monitoring circuit, a medium-voltage monitoring circuit, and a low-voltage monitoring circuit. The V output of the high-voltage monitoring circuit is connected to the control end of the medium-voltage monitoring single circuit. The V output of the medium-voltage monitoring circuit is connected to the control end of the low-voltage monitoring circuit. The outputs of the high-voltage monitoring circuit, the medium-voltage monitoring circuit, and the low-voltage monitoring circuit are all connected to the output V of the LX01 voltage monitoring circuit. O(H) The output of the high-voltage monitoring circuit is connected to the control end of the medium-voltage monitoring single circuit. The V output of the medium-voltage monitoring circuit is connected to the control end of the low-voltage monitoring circuit. O(M) The outputs of the high-voltage monitoring circuit, the medium-voltage monitoring circuit, and the low-voltage monitoring circuit are all connected to the output V of the LX01 voltage monitoring circuit. OD1 .

6. The control method of the battery-free thermometer and hygrometer device according to any one of claims 1-5, characterized in that, When the voltage at the input terminal V of the first LX01 voltage detection circuit in is lower than the threshold voltage V of the LX01 voltage detection circuit TH , the output V of the first LX01 voltage detection circuit OD1 remains low. When the voltage at the input terminal V of the first LX01 voltage detection circuit in is higher than the threshold voltage V of the LX01 voltage detection circuit TH , the output V of the first LX01 voltage detection circuit OD1 converts to high level and remains so until the voltage at the input terminal V of the first LX01 voltage detection circuit in is lower than the falling threshold voltage V of the LX01 voltage detection circuit TL . When there is light indoors, the photo energy harvesting converter board outputs a high voltage, and when the voltage exceeds V TH , the LX02 energy harvesting circuit is enabled. When there is no light indoors, the photo energy harvesting converter outputs a low voltage, and the LX02 energy harvesting circuit enters the shutdown state. The output of the LX02 energy harvesting circuit is VBAT, and VBAT is connected to the super capacitor C1. The positive electrode of the super capacitor C1 is connected to the first power management module, and the output of the first power management module is V DD1 , and V DD1 powers the timing trigger system. When a high voltage is output in the timing trigger system, the load temperature and humidity meter system is activated, and the temperature and humidity sensor starts to measure the temperature and humidity parameters. When the output V of the second LX01 voltage detection circuit OD2 is high, the switch NMOS-Q1 conducts, and the output voltage VBAT of the LX02 energy harvesting circuit is converted into the voltage required by the load through the second power management module, and the temperature and humidity meter system is activated. When the output V of the second LX01 voltage detection circuit OD2 is low, the switch NMOS-Q1 disconnects, the input of the second power management module is 0V, and its output is also 0V, and the temperature and humidity meter system is in the shutdown state, thereby removing the static power consumption of the temperature and humidity meter system and the second power management module. The frequency divider is used to control the duration of the period, which is determined by the number of bits of the frequency divider. The values of the resistor R3 and the capacitor C2 in the RC delay circuit are adjusted to control the duty cycle of the periodic signal, that is, the ratio of the time when the load is activated to the shutdown time.

7. The control method according to claim 6, characterized in that, The thermometer and hygrometer sensor measures the temperature and humidity parameters and transmits the parameters to the signal processing and control module. The signal processing and control module transmits the information to the bound gateway through the ZigBee module; the paper screen displays the corresponding temperature and humidity readings. When the load thermometer and hygrometer system is in shutdown during a cycle or when the output of the NAND gate is low, the paper screen still displays the temperature and humidity readings.

Images