Low-power electronic barometer and compressed oxygen self-rescuer

Abstract

This utility model discloses a low-power electronic barometer and a compressed oxygen self-rescue device, including a microcontroller and a power supply module. The microcontroller is electrically connected to a barometer circuit, an LCD screen, and a light intensity detection module. The light intensity detection module detects light intensity and outputs a light intensity signal to the microcontroller. The microcontroller switches between a working state and a low-power sleep / standby state based on the light intensity signal. This utility model employs a light-based wake-up mechanism, allowing the electronic barometer to remain in a low-power sleep / standby mode most of the time, only being woken up when needed. This effectively reduces power consumption, extends battery life, reduces battery replacement frequency, improves the ease of use and reliability of the device, and achieves significant energy savings.

Description

Technical Field

[0001] This utility model relates to the field of oxygen-related safety equipment technology, specifically, a low-power electronic pressure gauge and a compressed oxygen self-rescue device. Background Technology

[0002] Compressed oxygen self-rescue devices, used by coal miners or workers in special industries, are crucial equipment for ensuring life safety in emergencies by providing oxygen. Existing compressed oxygen self-rescue devices mainly consist of components such as a high-pressure oxygen cylinder, pressure gauge, pressure reducing valve, air bag, breathing apparatus, and safety valve, all housed in a waterproof casing. The high-pressure oxygen cylinder is the most critical component, equipped with a pressure gauge to indicate oxygen pressure. Currently, most self-rescue devices on the market use pointer-type pressure gauges, which do not require battery power. However, pointer-type pressure gauges have drawbacks such as less intuitive readings, lower accuracy, and limited functionality. With technological advancements, electronic pressure gauges have emerged. These gauges accurately measure oxygen pressure through microcontroller programming and related circuitry and software, displaying the readings intuitively on an LCD screen. This significantly improves the accuracy and intuitiveness of the readings and also allows for the expansion of functions such as communication and alarms.

[0003] However, electronic barometers require battery power. To ensure battery life, avoid frequent battery replacements, and reduce the overall circuit power consumption, this is an urgent problem to be solved.

[0004] When not in use, putting the circuitry of the electronic pressure gauge in a self-rescue device into sleep mode is the best way to reduce power consumption. However, after entering sleep mode, the electronic pressure gauge needs to be ready to be woken up at any time to provide pressure measurement and display to the user. Conventional electronic products typically wake up from sleep mode using physical buttons, communication commands, or a power button to shut down and restart. However, self-rescue devices are waterproof and sealed products, especially since the electronic pressure gauge is installed on the oxygen storage cylinder inside the device's casing. Using methods like buttons would complicate the structure, reduce waterproofing, safety, and reliability, and also increase costs. Utility Model Content

[0005] The purpose of this invention is to provide a low-power electronic barometer and a compressed oxygen self-rescue device, which solves the problems of continuous power supply to electronic barometers in the prior art, resulting in large battery power consumption, frequent battery replacement, and high power consumption of the entire circuit. It also addresses the issue that conventional button wake-up methods in the prior art are not suitable for electronic barometers in waterproof and sealed self-rescue devices.

[0006] The present invention solves the above problems through the following technical solution:

[0007] A low-power electronic barometer includes a microcontroller and a power module. The microcontroller is electrically connected to a barometer circuit, an LCD screen, and a light intensity detection module. The light intensity detection module is used to detect light intensity and output a light intensity signal to the microcontroller. The microcontroller switches between a working state and a low-power sleep / standby state according to the light intensity signal.

[0008] Working principle:

[0009] The microcontroller is set to a low-power sleep standby state that is woken up by I / O port interrupts. When the light intensity detection module detects that the light intensity exceeds the preset value, it outputs a signal to the microcontroller, and the I / O port interrupt wakes up the microcontroller. The microcontroller then switches from the low-power sleep standby state to the working state, starts and receives the pressure detection from the air pressure measurement circuit, and drives the LCD screen to display the air pressure value.

[0010] Alternatively, the microcontroller can be set to an internal low-frequency clock timer interrupt gap wake-up mode. Every so often (e.g., 1 or 2 seconds), the microcontroller is woken from its low-power sleep / standby state by this timer gap. After each wake-up, the microcontroller enters a working state, activates the light intensity detection module to detect the light intensity, inputs the detected value into the microcontroller, and compares it with a built-in preset light intensity threshold. If the light intensity exceeds the threshold, it activates and receives pressure detection from the air pressure measurement circuit and drives the LCD screen to display the air pressure value. If the light intensity does not exceed the threshold, or if an air pressure measurement observation ends after exceeding the threshold, the mining lamp is removed, and after a few seconds of delay, the microcontroller re-enters the low-power sleep / standby state of the internal low-frequency clock timer interrupt gap wake-up mode.

[0011] This invention enters a low-power sleep / standby state when the user is not monitoring the pressure reading, thus extending battery life. When the user needs to monitor the pressure reading, a self-rescue device is activated by illuminating it with a light source such as a mining lamp. The electronic pressure gauge detects the light intensity and is awakened, returning to the pressure measurement and display mode. This sleep / light-activated wake-up method significantly reduces the power consumption of the electronic pressure gauge and extends battery life.

[0012] Furthermore, the light intensity detection module includes a light detection unit and a light intensity comparison unit. The light intensity detection unit is used to detect the light intensity and input it to the light intensity comparison unit. The light intensity comparison unit is used to compare the detected light intensity with a preset light intensity threshold and output a high level or a low level to the microcontroller.

[0013] The light intensity detection unit detects the light intensity, and the light intensity comparison unit compares the detected value with a preset light intensity threshold. A high or low level output from the light intensity comparison unit interrupts and wakes the microcontroller, causing it to transition from a low-power sleep / standby state to an active state. The preset light intensity can be set using a voltage divider circuit; by changing the resistance value of the voltage divider resistor, the preset light intensity threshold can be altered.

[0014] Furthermore, the light detection unit includes a first photosensitive sensor and a resistor R1, and the light intensity comparison unit includes a first operational amplifier, a resistor R2, and a resistor R3. The first end of the first photosensitive sensor and the first end of the resistor R2 are connected to the power module. The second end of the first photosensitive sensor is connected to the first end of the resistor R1 and the positive input terminal of the first operational amplifier. The second end of the resistor R2 is connected to the first end of the resistor R3 and the negative input terminal of the first operational amplifier. The second ends of the resistor R1 and the second ends of the resistor R3 are grounded. The output terminal of the first operational amplifier is connected to the first I / O port of the microcontroller.

[0015] Furthermore, filter capacitors are connected in parallel across resistors R1 and R3 respectively.

[0016] Furthermore, the light intensity detection module includes a light detection unit and an impedance matching unit. The light detection unit is used to detect the light intensity and input it to the impedance matching unit. The impedance matching unit is used to achieve impedance matching with the internal analog-to-digital conversion circuit of the microcontroller. The impedance matching unit is connected to the input terminal of the analog-to-digital conversion circuit of the microcontroller. The light detection unit and the impedance matching unit are powered by one I / O port of the microcontroller.

[0017] The impedance matching unit achieves impedance matching with the internal A / D conversion circuit of the microcontroller. The voltage detected by the light detection unit is applied to the microcontroller's I / O port after passing through the impedance matching unit. The microcontroller compares the light detection value with a threshold preset by the internal software. When the light intensity exceeds the threshold, the microcontroller initiates and receives pressure detection from the air pressure measurement circuit and drives the LCD screen to display the air pressure value. If the light intensity does not exceed the threshold, or after the observation ends and the mining lamp is removed, the microcontroller enters a low-power state after a preset interval.

[0018] Furthermore, the light detection unit includes a second photosensitive sensor and a resistor R1', and the impedance matching unit includes a second operational amplifier. The first end of the second photosensitive sensor and the positive power supply terminal of the second operational amplifier are connected to the second I / O port of the microcontroller. The second end of the second photosensitive sensor is connected to the first end of the resistor R1' and the positive input terminal of the second operational amplifier. The negative input terminal and output terminal of the second operational amplifier are connected and connected to the third I / O port of the microcontroller. The second end of the resistor R1' and the negative power supply terminal of the second operational amplifier are grounded.

[0019] Furthermore, a filter capacitor is connected in parallel across the resistor R1'.

[0020] Furthermore, the fourth I / O port of the microcontroller is connected to an alarm device, which is used by the air pressure measurement circuit to issue an alarm when abnormal air pressure is detected.

[0021] The electronic barometer is also equipped with a waterproof housing, and the microcontroller, power module, barometer circuit, LCD screen and light intensity detection module are all installed inside the waterproof housing.

[0022] A compressed oxygen self-rescue device includes the aforementioned low-power electronic pressure gauge.

[0023] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0024] (1) By adopting a light-awakening mechanism, the electronic barometer is in a low-power sleep standby mode most of the time and is only awakened to work when needed, which effectively reduces power consumption, extends battery life, reduces battery replacement frequency, improves the convenience and reliability of the equipment, and has a significant energy-saving effect.

[0025] (2) Users of this utility model, miners, can easily wake up the barometer and enter working state by simply shining the observation window with the miner's lamp they carry with them, and check the oxygen pressure. The operation is simple and quick, which is in line with the actual use scenario in coal mines and is easy to operate.

[0026] (3) Based on the existing electronic barometer, this utility model only adds a light intensity detection module to its circuit board, which achieves low power consumption and low cost.

[0027] (4) This utility model provides a self-rescue device with a low-power electronic barometer. The electronic barometer with light wake-up function is installed on the oxygen storage cylinder inside the sealed shell of the self-rescue device. The user can use a light source such as a miner's lamp to shine on the observation window to wake up the electronic barometer and enter the working mode to measure and display the current air pressure value, which greatly facilitates the user and can extend the service time. It also eliminates the need for frequent battery replacements and facilitates underground mining operations.

[0028] (5) The reference light intensity value in this invention is adjustable, allowing for the design of a light-awakening reference point based on the specific application of the product. In particular, the size of the self-rescue device's observation window may vary, and the amount of ambient light entering may differ. Therefore, different actual products require different light-awakening reference points. The self-rescue device will only activate when the light intensity reaches a suitable level. This "suitability" is determined by comprehensively considering the battery capacity, the expected battery lifespan, and the lighting conditions of the operating environment.

[0029] (6) The entire casing of the self-rescue device is waterproof and sealed, except for the air pressure observation window, which is transparent and designed to allow users to easily observe the oxygen pressure. The pressure gauge and its front display panel are visible through the observation window. The rest of the casing is opaque. An electronic air pressure gauge with a light-activated wake-up function is installed on the oxygen storage cylinder inside the sealed casing. Users can illuminate the observation window with a light source such as a miner's lamp to activate the electronic air pressure gauge, which then measures and displays the current air pressure value. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the principle of this utility model;

[0031] Figure 2 This is a schematic diagram of one specific embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of another specific embodiment of the present invention;

[0033] Among them, IC1 is a three-terminal voltage regulator; IC2 is an operational amplifier; IC3 is a microcontroller; and PW1 is a battery. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0035] Example 1:

[0036] Combined with appendix Figure 1 As shown, a low-power electronic barometer includes a microcontroller IC3 and a power supply module. The microcontroller IC3 is electrically connected to a barometer circuit, an LCD screen, and a light intensity detection module. The light intensity detection module detects light intensity and outputs a light intensity signal to the microcontroller IC3. The microcontroller IC3 switches between a working state and a low-power sleep / standby state based on the light intensity signal. The power supply module supplies power to the microcontroller IC3. The light intensity detection module can be powered by either the microcontroller or the power supply module.

[0037] Working principle:

[0038] The microcontroller IC3 is set to a low-power sleep standby state that is woken up by I / O port interrupt. When the light intensity detection module detects that the light intensity exceeds the preset value, it outputs a signal to the microcontroller IC3, which is then woken up by the I / O port interrupt. The microcontroller IC3 then switches from the low-power sleep standby state to the working state, starts up and receives the pressure detection from the air pressure measurement circuit, and drives the LCD screen to display the air pressure value.

[0039] Alternatively, the microcontroller IC3 can be set to an internal low-frequency clock timer interrupt gap wake-up mode. Every so often (e.g., 1 or 2 seconds), the microcontroller IC3 is woken from its low-power sleep standby state by this timer gap. After each wake-up, the microcontroller IC3 enters a working state, activates the light intensity detection module to detect the light intensity, inputs the detected value to the microcontroller IC3, and compares it with a built-in preset light threshold. If the light intensity exceeds the threshold, it activates and receives pressure detection from the air pressure measurement circuit and drives the LCD screen to display the air pressure value. If the light intensity does not exceed the threshold, or if an air pressure measurement observation ends after exceeding the threshold, the mining lamp is removed, and after a few seconds of delay, the microcontroller IC3 re-enters the low-power sleep standby state of the internal low-frequency clock timer interrupt gap wake-up mode.

[0040] This invention enters a low-power sleep state when the user is not monitoring the pressure reading, thus extending battery life. When the user needs to monitor the pressure reading, a self-rescue device is activated by illuminating it with a light source such as a mining lamp. The electronic pressure gauge detects the light intensity and is awakened, returning to the pressure measurement and display mode. This sleep / light-activated wake-up method significantly reduces the power consumption of the electronic pressure gauge and extends battery life.

[0041] Existing electronic pressure gauges are constantly operating, consuming significant amounts of electrical energy. Self-rescue devices, on the other hand, are carried or stored in specialized work environments for emergency oxygen supply. The electronic pressure gauge within the device primarily allows workers to ascertain whether the oxygen supply is sufficient, i.e., whether the oxygen pressure is adequate, providing peace of mind. Therefore, this electronic pressure gauge does not need to operate continuously. Users only need to monitor the pressure when concerned about insufficient oxygen or inadequate pressure. For the majority of the time, users have neither the time nor the need to constantly monitor the pressure. Measuring and displaying pressure values ​​during these periods is meaningless. Putting the electronic pressure gauge into a low-power standby mode (sleep mode) is the best way to reduce power consumption and save electricity; standby current consumption can be kept below 10uA.

[0042] In outdoor or other work environments where self-rescue devices are carried, users can activate the electronic barometer to enter working mode by facing the observation window of the self-rescue device toward a strong light source in the environment, such as sunlight, streetlights, or searchlights.

[0043] Example 2:

[0044] Based on Embodiment 1, the light intensity detection module is powered by a power supply module. The light intensity detection module includes a light detection unit and a light intensity comparison unit. The light intensity detection unit is used to detect the light intensity and input it to the light intensity comparison unit. The light intensity comparison unit is used to compare the detected light intensity with a preset light intensity and output a high level or a low level to the microcontroller IC3.

[0045] The light detection unit detects the light intensity, and the light intensity comparison unit compares the detected value with the preset light intensity. A high or low level output from the light intensity comparison unit interrupts and wakes up the microcontroller IC3, causing it to switch from a low-power state to an active state. The preset light intensity can be set using a voltage divider circuit; changing the resistance value of the voltage divider resistors alters the preset light intensity value.

[0046] Combination Figure 2 As shown, the light detection unit includes a photosensitive sensor GM1 and a resistor R1. The light intensity comparison unit includes an operational amplifier IC2, resistors R2 and R3. The first terminal of the photosensitive sensor GM1 and the first terminal of the resistor R2 are connected to the power module (the power module uses a battery PW1, which outputs a 3.0V voltage through a three-terminal regulator IC1). The second terminal of the photosensitive sensor GM1 is connected to the first terminal of the resistor R1 and the positive input terminal of the operational amplifier IC2. The second terminal of the resistor R2 is connected to the first terminal of the resistor R3 and the negative input terminal of the operational amplifier IC2. The second terminals of the resistors R1 and R3 are grounded. The output terminal of the operational amplifier IC2 is connected to the first I / O port (PA3 pin) of the microcontroller IC3. Furthermore, a filter capacitor C1 is connected in parallel across the resistor R1, and a filter capacitor C2 is connected in parallel across the resistor R3.

[0047] principle:

[0048] The battery PW1 is labeled with a voltage of 3.6V, but its actual allowable voltage range is 3.2V to 4.2V. A low-dropout, low-self-discharge three-terminal regulator IC1 outputs a stable 3.0V voltage to power the entire circuit. The model number of the three-terminal regulator IC1 is CJ6101B30M, but other models of low-dropout, low-self-discharge three-terminal regulators can also be used. GM1 is a photosensitive sensor; in practical applications, a photodiode, phototransistor, or photoresistor can be used. This embodiment uses a PT0805BC photodiode. The 3.0V power supply is divided by resistors R2 and R3 to generate a reference voltage REF, which is applied to the "-" terminal of operational amplifier IC2. The photosensitive sensor GM1 outputs a current of 1uA to 30uA depending on the light intensity, which is then converted into a voltage through resistor R1 and applied to the "+" terminal of operational amplifier IC2. The output of operational amplifier IC2 is connected to the PA3 port of microcontroller IC3, and microcontroller IC3 sets PA3 to a high-level interrupt mode. Operational amplifier IC2 is designed to operate as a comparator, but a dedicated comparator chip can also be used. In this embodiment, operational amplifier IC2 is model RS8031XF, a low-power op-amp. When there is no light or the light is weak, the output current of the photosensor GM1 is small, the voltage across resistor R1 is lower than the set reference voltage REF, and operational amplifier IC2 outputs a low level. When the miner's lamp illuminates the area, the light intensity increases to the desired value, the voltage across resistor R1 rises above the reference voltage REF, and operational amplifier IC2 outputs a high level. This high level triggers an interrupt through the PA3 port of microcontroller IC3, waking up microcontroller IC3 and enabling the air pressure measurement and display. After observation, the miner's lamp is removed, and after a timer delay of 3-5 seconds (e.g., by the microcontroller), the electronic air pressure gauge enters a low-power sleep standby mode, waiting for the next light exposure to wake it up. In actual products, a suitable reference voltage REF is set by selecting an appropriate value for resistor R3 to determine the appropriate wake-up light intensity. Figure 2 In this example, the microcontroller IC3 is a low-power STM8L151F3U6TR. Other models can also be used.

[0049] Example 3:

[0050] Based on Example 1, the light intensity detection module is powered by a microcontroller IC3. The light intensity detection module includes a light detection unit and an impedance matching unit. The light detection unit is used to detect the light intensity and input it to the impedance matching unit. The impedance matching unit is used to achieve impedance matching with the analog-to-digital conversion circuit inside the microcontroller IC3. The impedance matching unit is connected to the input terminal of the analog-to-digital conversion circuit inside the microcontroller IC3. The light detection unit and the impedance matching unit are powered by one I / O port of the microcontroller IC3.

[0051] The impedance matching unit achieves impedance matching with the A / D conversion (analog-to-digital conversion) circuit inside the microcontroller IC3. The voltage detected by the light detection unit is applied to the I / O port of the microcontroller IC3 after passing through the impedance matching unit. The microcontroller IC3 compares the light detection value with a threshold value, which is a voltage value corresponding to a reference light intensity preset and stored in the microcontroller's internal memory during the microcontroller software design. When the light intensity exceeds the threshold, the pressure detection of the receiving air pressure measurement circuit is activated, and the LCD screen is driven to display the air pressure value. If the light intensity does not exceed the threshold, or after the observation ends and the mining lamp is removed, the microcontroller IC3 enters a low-power sleep standby state again after a certain delay display period.

[0052] Combination Figure 3 As shown, the light detection unit includes a photosensitive sensor GM1 and a resistor R1'. The impedance matching unit includes an operational amplifier IC2. The second terminal of the photosensitive sensor GM1 is connected to the first terminal of the resistor R1' and the positive input terminal of the operational amplifier IC2. The negative input and output terminals of the operational amplifier IC2 are connected and connected to the third I / O port (PB0 port) of the microcontroller IC3. The second terminal of the resistor R1' and the negative power supply terminal of the operational amplifier IC2 are grounded. Furthermore, a filter capacitor C1 is connected in parallel across the resistor R1'.

[0053] principle:

[0054] Battery PW1 has a labeled voltage of 3.6V, but its actual allowable voltage range is 3.2V to 4.2V. A low-dropout, low-self-discharge three-terminal regulator IC1 outputs a stable 3.0V voltage to power microcontroller IC3. The model number of the three-terminal regulator IC1 is CJ6101B30M, but other models of low-dropout, low-self-discharge three-terminal regulators can also be used. The photosensitive sensor GM1 can be a photodiode, phototransistor, or photoresistor in practical applications. This embodiment uses a PT0805BC photodiode. The photodiode outputs a current of 1uA to 30uA depending on the light intensity, which is then converted to voltage through resistor R1'. Operational amplifier IC2 is designed as a voltage emitter follower to achieve impedance matching with the internal A / D conversion circuit of microcontroller IC3. The voltage across resistor R1' is then applied to port PB0 of microcontroller IC3 after passing through operational amplifier IC2. Port PB0 is set to A / D conversion input mode. The photosensitive sensor GM1 and operational amplifier IC2 are powered by one I / O port of microcontroller IC3, such as... Figure 3 The PA2 port of IC3 is shown.

[0055] The principle behind achieving low power consumption and wake-up is as follows:

[0056] A timer was designed using the microcontroller's internal 32.768kHz low-frequency clock, with a suitable timing interval, such as 1 or 2 seconds. This timer was configured to operate in interrupt mode. After the microcontroller enters low-power sleep mode, this ultra-low-power timer interrupts and wakes the microcontroller every 1 or 2 seconds. Each time the microcontroller is woken up, it immediately sets the PA2 port to output a high level, powering the photosensitive and emitter follower circuits. Then, it initiates an A / D conversion to measure the voltage at the PB0 port, i.e., the voltage value of the photosensitive sensor's output signal, indirectly measuring the light intensity. This value is then compared with a software-preset reference voltage threshold. When the light intensity does not reach the preset threshold, the related measurement and display circuits are not activated. Instead, the PA2 port is immediately set to output a low level, shutting off the power supply to the photosensitive sensor GM1 and the emitter follower circuit. This allows the microcontroller IC3 to enter a low-power sleep standby state, waiting for the next timer interrupt to wake it up. This process is completed within 100µs, resulting in very low average system power consumption. Once the light intensity reaches the preset threshold, a barometric pressure measurement and display cycle is initiated. Then, another preset timer is activated, for example, 3-5 seconds. After this, the microcontroller IC3 shuts down the relevant circuits and enters a low-power sleep / standby state, awaiting the next timer interrupt wake-up and A / D conversion to measure the light intensity. Figure 3 The microcontroller IC3 used is the low-power STM8L151F3U6TR. Other microcontrollers with a built-in 32.768kHz low-frequency clock source can also be used. The improvement of this invention lies in the fact that the air pressure measurement circuit and LCD display are activated based on the detected light intensity, and the microcontroller remains in a low-power sleep / standby state most of the time when the light intensity does not meet the preset conditions.

[0057] Furthermore, the fourth I / O port of the microcontroller IC3 is connected to an alarm device, used to issue an alarm when the air pressure measurement circuit detects an abnormal air pressure. Figure 2 and Figure 3 As shown, the PC0 port of the microcontroller IC3 is connected to an LED through a resistor R4. When the air pressure is not up to standard, the LED flashes to sound an alarm.

[0058] Preferably, the electronic barometer is further provided with a waterproof housing, and the microcontroller, power module, barometer circuit, LCD screen and light intensity detection module are all installed inside the waterproof housing.

[0059] Example 4:

[0060] A compressed oxygen self-rescue device includes the aforementioned low-power electronic pressure gauge.

[0061] Although the present invention has been described herein with reference to illustrative embodiments, the above embodiments are merely preferred embodiments of the present invention, and the implementation of the present invention is not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A low-power electronic barometer, comprising a microcontroller and a power module, characterized in that, The microcontroller is electrically connected to a barometric pressure measurement circuit, an LCD screen, and a light intensity detection module. The light intensity detection module is used to detect light intensity and output a light intensity signal to the microcontroller. The microcontroller switches between a working state and a low-power sleep / standby state based on the light intensity signal.

2. The low-power electronic barometer according to claim 1, characterized in that, The light intensity detection module includes a light detection unit and a light intensity comparison unit. The light intensity detection unit is used to detect the light intensity and input it to the light intensity comparison unit. The light intensity comparison unit is used to compare the detected light intensity with a preset light intensity and output a high level or a low level to the microcontroller.

3. A low-power electronic barometer according to claim 2, characterized in that, The light detection unit includes a first photosensitive sensor and a resistor R1. The light intensity comparison unit includes a first operational amplifier, a resistor R2, and a resistor R3. The first end of the first photosensitive sensor and the first end of the resistor R2 are connected to the power module. The second end of the first photosensitive sensor is connected to the first end of the resistor R1 and the positive input terminal of the first operational amplifier. The second end of the resistor R2 is connected to the first end of the resistor R3 and the negative input terminal of the first operational amplifier. The second ends of the resistor R1 and the second ends of the resistor R3 are grounded. The output terminal of the first operational amplifier is connected to the first I / O port of the microcontroller.

4. A low-power electronic barometer according to claim 3, characterized in that, Filter capacitors are connected in parallel across resistors R1 and R3 respectively.

5. A low-power electronic barometer according to claim 1, characterized in that, The light intensity detection module includes a light detection unit and an impedance matching unit. The light detection unit is used to detect the light intensity and input it to the impedance matching unit. The impedance matching unit is used to achieve impedance matching with the analog-to-digital conversion circuit of the microcontroller. The impedance matching unit is connected to the input terminal of the analog-to-digital conversion circuit of the microcontroller. The light detection unit and the impedance matching unit are powered by one I / O port of the microcontroller.

6. A low-power electronic barometer according to claim 5, characterized in that, The light detection unit includes a second photosensitive sensor and a resistor R1'. The impedance matching unit includes a second operational amplifier. The first end of the second photosensitive sensor and the positive power supply terminal of the second operational amplifier are connected to the second I / O port of the microcontroller. The second end of the second photosensitive sensor is connected to the first end of the resistor R1' and the positive input terminal of the second operational amplifier. The negative input terminal and output terminal of the second operational amplifier are connected and connected to the third I / O port of the microcontroller. The second end of the resistor R1' and the negative power supply terminal of the second operational amplifier are grounded.

7. A low-power electronic barometer according to claim 6, characterized in that, A filter capacitor is connected in parallel across the resistor R1'.

8. A low-power electronic barometer according to any one of claims 1-7, characterized in that, The microcontroller's fourth I / O port is connected to an alarm device.

9. A low-power electronic barometer according to any one of claims 1-7, characterized in that, The electronic barometer is also equipped with a waterproof casing.

10. A compressed oxygen self-rescue device, characterized in that, Including a low-power electronic barometer as described in any one of claims 1-9.

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