Circuit for realizing distance and existence detection based on infrared transmitting tube and receiving tube

Abstract

The utility model discloses a circuit for realizing distance and existence detection based on an infrared transmitting tube and an infrared receiving tube, which is characterized by comprising a power supply circuit, a voltage stabilizing circuit, a signal amplifying, filtering and sampling circuit and an MCU (Microprogrammed Control Unit) processor, the power supply circuit is connected with one end of the voltage stabilizing circuit, the other end of the voltage stabilizing circuit is connected with one end of the signal amplification filtering sampling circuit, and the other end of the signal amplification filtering sampling circuit is connected with the MCU processor. According to the utility model, the infrared transmitting tube and the infrared receiving tube are arranged side by side, the infrared transmitting tube is driven by a circuit to transmit light, when an object shields, the infrared receiving tube is connected with the operational amplifier circuit to amplify a signal, the signal is filtered by the filter circuit, and then the ADC acquires the signal and detects the signal strength, so that distance measurement and object existence induction are realized. An IC does not need to be driven, only a transmitting tube and a receiving tube are needed, distance detection and existence detection are achieved through a hardware circuit, and cost is lower.

Description

Technical Field

[0001] This utility model relates to the field of infrared detection technology, specifically to a distance and presence detection circuit based on an infrared emitting tube and a receiving tube. Background Technology

[0002] The basic principle of infrared detection is that an infrared emitting tube emits invisible infrared light, which is reflected by the detection surface and received by the infrared receiving tube, thereby detecting objects or distances.

[0003] Typically, an infrared detection device has a pair of infrared signal transmitters and receivers. The transmitter emits infrared signals, and the receiver receives them. When the infrared signal encounters an obstacle in the detection direction, it is reflected back and received by the receiver. The closer the obstacle, the stronger the reflected infrared signal received by the receiver. After receiving the infrared signal, the receiver outputs a certain voltage; the stronger the infrared signal, the higher the output voltage.

[0004] In existing technologies, infrared emitting diodes are typically driven by driver ICs to emit light, which results in higher costs when designing infrared detection devices. Utility Model Content

[0005] In view of this, in order to solve the above-mentioned problems in the prior art, this utility model proposes a distance and presence detection circuit based on an infrared emitting tube and a receiving tube, which does not require a driver IC, and drives the infrared emitting tube to emit light through the circuit, thus reducing costs.

[0006] This utility model solves the above problems through the following technical means:

[0007] A distance and presence detection circuit based on an infrared emitting and receiving tube includes a power supply circuit, a voltage regulator circuit, a signal amplification, filtering and sampling circuit, and an MCU processor. The power supply circuit is connected to one end of the voltage regulator circuit, the other end of the voltage regulator circuit is connected to one end of the signal amplification, filtering and sampling circuit, and the other end of the signal amplification, filtering and sampling circuit is connected to the MCU processor.

[0008] Preferably, the power supply circuit includes a chip U7. Pin 1 of chip U7 is grounded. Pin 3 of chip U7 is connected to one end of resistor R30, one end of capacitor C30, one end of capacitor C28, one end of capacitor C27, the positive terminal of polarized capacitor C29, one end of bidirectional TVS diode D3, and the negative terminal of diode D2. The positive terminal of diode D2 is connected to the positive terminal of the power supply. The other end of bidirectional TVS diode D3 is grounded. The negative terminal of polarized capacitor C29 is grounded. The other end of capacitor C30 is connected to the other ends of capacitors C28 and C27 and grounded. Pin 5 of chip U7 is connected to the other end of resistor R30 and one end of resistor R31. The other end of resistor R31 is grounded. Pin 6 of chip U7 is connected to one end of capacitor C32. The other end of capacitor C32 is connected to pin 2 of chip U7 and the coil. One end of L2 and the other end of coil L2 are connected to one end of capacitor C37, one end of capacitor C39, one end of resistor R37, one end of capacitor C41, one end of capacitor C42, one end of capacitor C43 and one end of resistor R47 respectively. The other end of resistor R47 is connected to the positive terminal of LED D5, and the negative terminal of LED D5 is grounded. The other end of capacitor C37 is connected to the other end of capacitor C39 and grounded. The other end of capacitor C42 is connected to the other end of capacitor C43 and grounded. Pin 4 of chip U7 is connected to one end of capacitor C40, one end of resistor R38, one end of resistor R39 and one end of resistor R44 respectively. The other end of resistor R39 is grounded. The other end of capacitor C40 is connected to the other ends of resistor R38 and resistor R37 respectively. The other end of resistor R44 is connected to the other end of capacitor C41.

[0009] Preferably, the chip U7 is model number 54302.

[0010] Preferably, the power supply circuit is a 12V to 5V power supply circuit.

[0011] Preferably, the voltage regulator circuit includes a chip U3. Pin 1 of chip U3 is connected to one end of capacitor C15, one end of capacitor C16 and one end of capacitor C43 respectively. The other end of capacitor C15 is grounded, the other end of capacitor C16 is grounded, pin 3 of chip U3 is grounded, and pin 5 of chip U3 is connected to one end of capacitor C21 and one end of capacitor C22 respectively. The other end of capacitor C21 is grounded, and the other end of capacitor C22 is grounded.

[0012] Preferably, the chip U3 is model SCT74331Q.

[0013] Preferably, the voltage regulator circuit is a 3.3V voltage regulator circuit.

[0014] Preferably, the signal amplification, filtering, and sampling circuit includes an amplifier U1A. The non-inverting input terminal of the amplifier U1A is connected to one end of a capacitor C7, one end of a resistor R1, and the emitter (E) of a phototransistor Q1. The other end of the capacitor C7 is grounded, and the other end of the resistor R1 is grounded. The collector (C) of the phototransistor Q1 is connected to the anode of an LED D1 and pin 5 of a chip U3. The cathode of the LED D1 is connected to one end of a resistor R3, and the other end of the resistor R3 is grounded. The positive power supply terminal of the amplifier U1A is connected to pin 1 of the chip U3, and the negative power supply terminal of the amplifier U1A is grounded. The inverting input terminal of the amplifier U1A is connected to the output terminal of the amplifier U1A and one end of a resistor R4. The other end of the resistor R4 is connected to one end of a capacitor C8, and the other end of the capacitor C8 is grounded.

[0015] Preferably, the MCU processor includes a chip U2. Pin 5 of chip U2 is connected to one end of resistor R6 and one end of capacitor C5. The other end of resistor R6 is connected to the collector (C) of phototransistor Q1. The other end of capacitor C5 is grounded. Pin 10 of chip U2 is connected to one end of resistor R7, and the other end of resistor R7 is grounded. Pin 11 of chip U2 is connected to one end of capacitor C6, one end of capacitor C4, and one end of ferrite bead FB1. The other end of ferrite bead FB1 is connected to one end of capacitor C3, one end of capacitor C2, one end of capacitor C1, and the other end of resistor R6. One end of capacitor C3 is connected to the other ends of capacitor C2, capacitor C1, and resistor R2 and grounded. The other end of capacitor C6 is connected to the other ends of capacitor C4 and resistor R2 and grounded. Pin 13 of chip U2 is grounded. Pin 14 of chip U2 is connected to the other end of resistor R6. Pin 15 of chip U2 is connected to the other end of resistor R4. Pin 16 of chip U2 is connected to one end of capacitor C13. The other end of capacitor C13 is grounded. Pin 25 of chip U2 is connected to one end of capacitor C17 and one end of capacitor C18. The other end of capacitor C17 and the other end of capacitor C18 are grounded. Pin 27 of chip U2 is connected to one end of resistor R20. Pin 28 of chip U2 is connected to one end of resistor R19. Pin 39 of chip U2 is connected to one end of resistor R28. The other end of resistor R28 is connected to pin 4 of terminal P4. Pin 40 of chip U2 is connected to one end of resistor R29. Resistor R29... The other end is connected to pin 5 of terminal P4. Pin 41 of chip U2 is connected to pin 3 of terminal P4. Pin 42 of chip U2 is connected to pin 2 of terminal P4 and one end of resistor R18. The other end of resistor R18 is connected to the other end of resistor R6. Pin 1 of terminal P4 is connected to the other end of resistor R6. Pin 6 of terminal P4 is grounded. Pin 7 of terminal P4 is connected to pin 8 of terminal P4 and grounded. Pin 43 of chip U2 is connected to one end of resistor R17. Pin 45 of chip U2 is connected to one end of resistor R16.

[0016] Preferably, the chip U2 is model KF32A141IQS.

[0017] Compared with the prior art, the beneficial effects of this utility model include at least the following:

[0018] This invention features an infrared emitting tube and an infrared receiving tube placed side-by-side. The emitting tube is driven by a circuit to emit light. When an object blocks the light, the receiving tube amplifies the signal via an operational amplifier circuit, filters it through a filter circuit, and then acquires the signal via an ADC to detect the signal strength, thereby achieving distance measurement and object presence detection. No driver IC is required; only the emitting and receiving tubes are needed. Distance and presence detection are achieved through hardware circuitry, resulting in lower costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the distance and presence detection circuit based on an infrared emitting tube and a receiving tube.

[0021] Figure 2 This is a schematic diagram of the power supply circuit of this utility model;

[0022] Figure 3 This is a schematic diagram of the voltage regulator circuit of this utility model;

[0023] Figure 4 This is a schematic diagram of the signal amplification, filtering, and sampling circuit of this utility model;

[0024] Figure 5 This is the schematic diagram of the MCU processor of this utility model. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the described embodiments are merely some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0026] like Figure 1As shown, this utility model provides a distance and presence detection circuit based on an infrared emitting tube and a receiving tube, including a power supply circuit, a voltage regulator circuit, a signal amplification, filtering and sampling circuit and an MCU processor; the power supply circuit is connected to one end of the voltage regulator circuit, the other end of the voltage regulator circuit is connected to one end of the signal amplification, filtering and sampling circuit, and the other end of the signal amplification, filtering and sampling circuit is connected to the MCU processor.

[0027] This invention features a transmitter and receiver arranged side-by-side on a circuit board. A constant current source circuit continuously emits light signals. The receiver is connected to an operational amplifier circuit with a low-pass or band-pass filter to extract the signal. The signal is then acquired by an ADC (Analog-Digital Converter) peripheral on the main control MCU and converted into a voltage signal. The received signal strength is recorded at different distances to establish a distance-voltage curve or mapping table, thereby achieving distance measurement. However, the signal can be affected by ambient light or other interference. Therefore, the reference value needs to be dynamically updated. When there is no target object, the ADC continuously acquires the receiver output value, performs a moving average filter, averages the noise (by averaging sampled values ​​over a certain period), and continuously updates the reference value. The updated value is always proportional to the unupdated value, and a new mapping relationship is calculated.

[0028] Presence sensing involves setting a threshold based on distance measurement; if the distance is less than the trigger threshold, it indicates presence, and vice versa.

[0029] like Figure 2As shown, the power supply circuit includes chip U7. Pin 1 of chip U7 is grounded. Pin 3 of chip U7 is connected to one end of resistor R30, one end of capacitor C30, one end of capacitor C28, one end of capacitor C27, the positive terminal of polarized capacitor C29, one end of bidirectional TVS diode D3, and the negative terminal of diode D2. The positive terminal of diode D2 is connected to the positive terminal of the power supply. The other end of bidirectional TVS diode D3 is grounded. The negative terminal of polarized capacitor C29 is grounded. The other end of capacitor C30 is connected to the other ends of capacitors C28 and C27 and grounded. Pin 5 of chip U7 is connected to the other end of resistor R30 and one end of resistor R31. The other end of resistor R31 is grounded. Pin 6 of chip U7 is connected to one end of capacitor C32. The other end of capacitor C32 is connected to pin 2 of chip U7 and coil L2. One end of the coil L2 is connected to one end of capacitor C37, one end of capacitor C39, one end of resistor R37, one end of capacitor C41, one end of capacitor C42, one end of capacitor C43 and one end of resistor R47 respectively. The other end of resistor R47 is connected to the positive terminal of LED D5, and the negative terminal of LED D5 is grounded. The other end of capacitor C37 is connected to the other end of capacitor C39 and grounded. The other end of capacitor C42 is connected to the other end of capacitor C43 and grounded. Pin 4 of chip U7 is connected to one end of capacitor C40, one end of resistor R38, one end of resistor R39 and one end of resistor R44 respectively. The other end of resistor R39 is grounded. The other end of capacitor C40 is connected to the other ends of resistor R38 and resistor R37 respectively. The other end of resistor R44 is connected to the other end of capacitor C41.

[0030] In this embodiment, the chip U7 is model 54302; the power supply circuit is a 12V to 5V power supply circuit.

[0031] like Figure 3 As shown, the voltage regulator circuit includes a chip U3. Pin 1 of chip U3 is connected to one end of capacitor C15, one end of capacitor C16, and one end of capacitor C43, respectively. The other end of capacitor C15 is grounded, the other end of capacitor C16 is grounded, and pin 3 of chip U3 is grounded. Pin 5 of chip U3 is connected to one end of capacitor C21 and one end of capacitor C22, respectively. The other end of capacitor C21 is grounded, and the other end of capacitor C22 is grounded.

[0032] In this embodiment, the chip U3 is model SCT74331Q; the voltage regulator circuit is a 3.3V voltage regulator circuit.

[0033] like Figure 4As shown, the signal amplification, filtering, and sampling circuit includes amplifier U1A. The non-inverting input terminal of amplifier U1A is connected to one end of capacitor C7, one end of resistor R1, and the emitter (E) of phototransistor Q1. The other end of capacitor C7 is grounded, and the other end of resistor R1 is grounded. The collector (C) of phototransistor Q1 is connected to the anode of LED D1 and pin 5 of chip U3. The cathode of LED D1 is connected to one end of resistor R3, and the other end of resistor R3 is grounded. The positive power supply terminal of amplifier U1A is connected to pin 1 of chip U3, and the negative power supply terminal of amplifier U1A is grounded. The inverting input terminal of amplifier U1A is connected to the output terminal of amplifier U1A and one end of resistor R4. The other end of resistor R4 is connected to one end of capacitor C8, and the other end of capacitor C8 is grounded.

[0034] like Figure 5 As shown, the MCU processor includes chip U2. Pin 5 of chip U2 is connected to one end of resistor R6 and one end of capacitor C5. The other end of resistor R6 is connected to the collector (C) of phototransistor Q1. The other end of capacitor C5 is grounded. Pin 10 of chip U2 is connected to one end of resistor R7, and the other end of resistor R7 is grounded. Pin 11 of chip U2 is connected to one end of capacitor C6, one end of capacitor C4, and one end of ferrite bead FB1. The other end of ferrite bead FB1 is connected to one end of capacitor C3, one end of capacitor C2, one end of capacitor C1, and the other end of resistor R6. One end of capacitor C3 is connected to the other ends of capacitor C2, capacitor C1, and resistor R2 and grounded. The other end of capacitor C6 is connected to the other ends of capacitor C4 and resistor R2 and grounded. Pin 13 of chip U2 is grounded. Pin 14 of chip U2 is connected to the other end of resistor R6. Pin 15 of chip U2 is connected to the other end of resistor R4. Pin 16 of chip U2 is connected to one end of capacitor C13. The other end of capacitor C13 is grounded. Pin 25 of chip U2 is connected to one end of capacitor C17 and one end of capacitor C18, respectively. The other end of capacitor C17 and the other end of capacitor C18 are grounded. Pin 27 of chip U2 is connected to one end of resistor R20. Pin 28 of chip U2 is connected to one end of resistor R19. Pin 39 of chip U2 is connected to one end of resistor R28. The other end of resistor R28 is connected to pin 4 of terminal P4. Pin 40 of chip U2 is connected to one end of resistor R29. Resistor R29... The other end is connected to pin 5 of terminal P4. Pin 41 of chip U2 is connected to pin 3 of terminal P4. Pin 42 of chip U2 is connected to pin 2 of terminal P4 and one end of resistor R18. The other end of resistor R18 is connected to the other end of resistor R6. Pin 1 of terminal P4 is connected to the other end of resistor R6. Pin 6 of terminal P4 is grounded. Pin 7 of terminal P4 is connected to pin 8 of terminal P4 and grounded. Pin 43 of chip U2 is connected to one end of resistor R17. Pin 45 of chip U2 is connected to one end of resistor R16.

[0035] In this embodiment, the chip U2 is model KF32A141IQS.

[0036] This invention features an infrared emitting tube and an infrared receiving tube placed side-by-side. The emitting tube is driven by a circuit to emit light. When an object blocks the light, the receiving tube amplifies the signal via an operational amplifier circuit, filters it through a filter circuit, and then acquires the signal via an ADC to detect the signal strength, thereby achieving distance measurement and object presence detection. No driver IC is required; only the emitting and receiving tubes are needed. Distance and presence detection are achieved through hardware circuitry, resulting in lower costs.

[0037] This invention can be applied to smart surfaces in automotive interiors. When a person is detected approaching, the smart surface will perform corresponding actions, such as turning on ambient lighting or making voice announcements.

[0038] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A distance and presence detection circuit based on an infrared emitting diode and a receiving diode, characterized in that, It includes a power supply circuit, a voltage regulator circuit, a signal amplification, filtering and sampling circuit, and an MCU processor; the power supply circuit is connected to one end of the voltage regulator circuit, the other end of the voltage regulator circuit is connected to one end of the signal amplification, filtering and sampling circuit, and the other end of the signal amplification, filtering and sampling circuit is connected to the MCU processor.

2. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 1, characterized in that, The power supply circuit includes chip U7. Pin 1 of chip U7 is grounded. Pin 3 of chip U7 is connected to one end of resistor R30, one end of capacitor C30, one end of capacitor C28, one end of capacitor C27, the positive terminal of polarized capacitor C29, one end of bidirectional TVS diode D3, and the negative terminal of diode D2. The positive terminal of diode D2 is connected to the positive terminal of the power supply. The other end of bidirectional TVS diode D3 is grounded. The negative terminal of polarized capacitor C29 is grounded. The other end of capacitor C30 is connected to the other ends of capacitors C28 and C27 and grounded. Pin 5 of chip U7 is connected to the other end of resistor R30 and one end of resistor R31. The other end of resistor R31 is grounded. Pin 6 of chip U7 is connected to one end of capacitor C32. The other end of capacitor C32 is connected to pin 2 of chip U7 and coil L2. One end of coil L2 is connected to one end of capacitor C37, one end of capacitor C39, one end of resistor R37, one end of capacitor C41, one end of capacitor C42, one end of capacitor C43, and one end of resistor R47. The other end of resistor R47 is connected to the positive terminal of LED D5, and the negative terminal of LED D5 is grounded. The other end of capacitor C37 is connected to the other end of capacitor C39 and grounded. The other end of capacitor C42 is connected to the other end of capacitor C43 and grounded. Pin 4 of chip U7 is connected to one end of capacitor C40, one end of resistor R38, one end of resistor R39, and one end of resistor R44. The other end of resistor R39 is grounded. The other end of capacitor C40 is connected to the other ends of resistor R38 and resistor R37. The other end of resistor R44 is connected to the other end of capacitor C41.

3. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 2, characterized in that, The model number of the chip U7 is 54302.

4. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 2, characterized in that, The power supply circuit is a 12V to 5V power supply circuit.

5. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 2, characterized in that, The voltage regulator circuit includes a chip U3. Pin 1 of chip U3 is connected to one end of capacitor C15, one end of capacitor C16 and one end of capacitor C43 respectively. The other end of capacitor C15 is grounded, the other end of capacitor C16 is grounded, and pin 3 of chip U3 is grounded. Pin 5 of chip U3 is connected to one end of capacitor C21 and one end of capacitor C22 respectively. The other end of capacitor C21 is grounded, and the other end of capacitor C22 is grounded.

6. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 5, characterized in that, The chip U3 is model SCT74331Q.

7. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 5, characterized in that, The voltage regulator circuit is a 3.3V voltage regulator circuit.

8. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 5, characterized in that, The signal amplification, filtering, and sampling circuit includes amplifier U1A. The non-inverting input terminal of amplifier U1A is connected to one end of capacitor C7, one end of resistor R1, and the emitter (E) of phototransistor Q1. The other end of capacitor C7 is grounded, and the other end of resistor R1 is grounded. The collector (C) of phototransistor Q1 is connected to the anode of LED D1 and pin 5 of chip U3. The cathode of LED D1 is connected to one end of resistor R3, and the other end of resistor R3 is grounded. The positive power supply terminal of amplifier U1A is connected to pin 1 of chip U3, and the negative power supply terminal of amplifier U1A is grounded. The inverting input terminal of amplifier U1A is connected to the output terminal of amplifier U1A and one end of resistor R4. The other end of resistor R4 is connected to one end of capacitor C8, and the other end of capacitor C8 is grounded.

9. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 8, characterized in that, The MCU processor includes chip U2. Pin 5 of chip U2 is connected to one end of resistor R6 and one end of capacitor C5. The other end of resistor R6 is connected to the collector (C) of phototransistor Q1. The other end of capacitor C5 is grounded. Pin 10 of chip U2 is connected to one end of resistor R7, and the other end of resistor R7 is grounded. Pin 11 of chip U2 is connected to one end of capacitor C6, one end of capacitor C4, and one end of ferrite bead FB1. The other end of ferrite bead FB1 is connected to one end of capacitor C3, one end of capacitor C2, one end of capacitor C1, and the other end of resistor R6. One end of capacitor C3 is connected to the other ends of capacitor C2, capacitor C1, and resistor R2 and grounded. The other end of capacitor C6 is connected to the other ends of capacitor C4 and resistor R2 and grounded. Pin 13 of chip U2 is grounded. Pin 14 of chip U2 is connected to the other end of resistor R6. Pin 15 of chip U2 is connected to the other end of resistor R4. Pin 16 of chip U2 is connected to one end of capacitor C13. The other end of chip 13 is grounded. Pin 25 of chip U2 is connected to one end of capacitor C17 and one end of capacitor C18, respectively. The other end of capacitor C17 and the other end of capacitor C18 are grounded. Pin 27 of chip U2 is connected to one end of resistor R20. Pin 28 of chip U2 is connected to one end of resistor R19. Pin 39 of chip U2 is connected to one end of resistor R28. The other end of resistor R28 is connected to pin 4 of terminal P4. Pin 40 of chip U2 is connected to one end of resistor R29. The other end of resistor R29... One end is connected to pin 5 of terminal P4, pin 41 of chip U2 is connected to pin 3 of terminal P4, pin 42 of chip U2 is connected to pin 2 of terminal P4 and one end of resistor R18 respectively, the other end of resistor R18 is connected to the other end of resistor R6, pin 1 of terminal P4 is connected to the other end of resistor R6, pin 6 of terminal P4 is grounded, pin 7 of terminal P4 is connected to pin 8 of terminal P4 and grounded, pin 43 of chip U2 is connected to one end of resistor R17, and pin 45 of chip U2 is connected to one end of resistor R16.

10. The distance and presence detection circuit based on an infrared emitting tube and a receiving tube according to claim 9, characterized in that, The chip U2 is model number KF32A141IQS.

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