Here we will consider sound and touch sensors, most often used as part of alarm systems.

Touch sensor module KY-036

The module is essentially a touch button. As the author understands, the principle of operation of the device is based on the fact that, by touching the contact of the sensor, a person becomes an antenna for receiving interference at the frequency household network AC. These signals are sent to the comparator LM393YD

The module dimensions are 42 x 15 x 13 mm, weight 2.8 g, the module board has a mounting hole with a diameter of 3 mm. Power is indicated by LED L1.

When the sensor is triggered, LED L2 lights up (flashes). Current consumption is 3.9 mA in standby mode and 4.9 mA when triggered.

It is not entirely clear what sensitivity threshold of the sensor should be regulated by a variable resistor. These modules with the LM393YD comparator are standard and various sensors are soldered to them, thus obtaining modules for various purposes. Power terminals “G” – common wire, “+” – +5V power supply. There is a low logic level at the digital input “D0”; when the sensor is triggered, pulses with a frequency of 50 Hz appear at the output. At pin “A0” there is a signal inverted relative to “D0”. In general, the module works discretely, like a button, which can be verified using the LED_with_button program.

The touch sensor allows you to use any metal surface as a control button; the absence of moving parts should have a positive effect on durability and reliability.

Sound sensor module KY-037

The module must be triggered by sounds whose volume exceeds a specified limit. The sensitive element of the module is a microphone that works together with a comparator on the LM393YD chip.

The module dimensions are 42 x 15 x 13 mm, weight 3.4 g, similar to the previous case, the module board has a mounting hole with a diameter of 3 mm. Power indication is provided by LED L1. Power terminals “G” – common wire, “+” – +5V power supply.

Current consumption is 4.1 mA in standby mode and 5 mA when triggered.

At pin “A0” the voltage changes in accordance with the volume level of the signals received by the microphone; as the volume increases, the readings decrease, this can be verified using the AnalogInput2 program.

There is a low logic level at the digital input “D0” when the specified threshold is exceeded low level changes to high. The response threshold can be adjusted with a variable resistor. In this case, LED L2 lights up. With a sharp loud sound, there is a delay of 1-2 s when switching back.

Overall, a useful sensor for organizing a smart home or alarm system.

Sound sensor module KY-038

At first glance, the module seems similar to the previous one. The sensitive element of the module is the microphone; it should be noted that there is not much information on this module on the network.

The module dimensions are 40 x 15 x 13 mm, weight 2.8 g, similar to the previous case, the module board has a mounting hole with a diameter of 3 mm. Power is indicated by LED L1. Power terminals “G” – common wire, “+” – +5V power supply.

When the reed switch is activated, LED L2 lights up. Current consumption is 4.2 mA in standby mode and up to 6 mA when triggered.

At pin “A0”, when the volume level increases, the readings increase (the AnalogInput2 program was used).

There is a low logic level at pin “D0”; when the sensor is triggered, it changes to high. The response threshold is adjusted using a trimming resistor (using the LED_with_button program).

This sensor really is practically no different from the previous one, but their interchangeability is not always possible, because When the volume level changes, the nature of the level change causes the voltage at the analog output to differ.

Conclusions

This concludes the review of a large set of various sensors for the Arduino hardware platform. In general, this set made a mixed impression on the author. The set includes both fairly complex sensors and completely simple designs. And if, if there are current-limiting resistors, LED indicators, etc. on the board, the author is ready to admit the usefulness of such modules, then a small part of the modules is a single radio element on the board. Why such modules are needed remains unclear (apparently, mounting on standard boards serves the purpose of unification). Overall, the kit is a good way to get acquainted with most of the common sensors used in Arduino projects.

Useful links

1. http://arduino-kit.ru/catalog/id/modul-datchika-kasaniya
2. http://www.zi-zi.ru/module/module-ky036
3. http://robocraft.ru/blog/arduino/57.html
4. http://arduino-kit.ru/catalog/id/modul-datchika-zvuka
5. http://www.zi-zi.ru/module/module-ky037
6. http://arduino-kit.ru/catalog/id/modul-datchika-zvuka_
7. http://smart-boards.ml/module-audiovideo-4.php

With the development of civilization, electricity has become an integral part of our daily life. Today it is possible to use a wide variety of innovations and technical innovations right in your home.

Lighting in the home has always been one of the most important aspects comfortable stay in it. But how many times have you encountered a situation when you need to turn on the light, but you can’t immediately find the switch in the dark? Modern technologies, which are now ubiquitous in our homes, are designed to eliminate such awkward moments. Now you can use it to turn on the light in the room sensor responsive to sound.

Sound sensor

A device such as a sound sensor has recently begun to enjoy noticeable popularity, since to a certain extent it allows us to make our lives more comfortable and practical.

Let's talk about the sensor

Sensor for turning on the light in the room using sound signal appeared on sale relatively recently. It is a special device consisting of a special structure into which a light bulb is inserted. Sometimes it has the form of a cartridge, but most often it is found in the form of a plastic box.

It responds to sound signals, thanks to which the light turns on. A clap of your hands can act as a sound signal.

Pay attention! This method of switching on is very convenient, but only in a situation where your hands are free. Therefore, some sensors can be programmed for a specific sound signal, which will turn on the light.

Installing such equipment allows you to reduce energy costs, since many of us, being too lazy to reach for the switch, simply do not turn off the light when it is not particularly needed. In addition, moving around the house in the evening will become more comfortable and safe, since when entering a room the light can be turned on using sound, avoiding blind actions. It is the light that is not turned on in time that very often leads to injuries.

Types of devices

Today, sensors for turning on light in a room via an audio signal can be of the following types:

• standard sound;
• a sound device that also reacts to movement;

Motion sensor

• sensor with photocells. It monitors the level of general illumination present in the room and, if necessary, independently monitors whether the lights are turned on or off.

Pay attention! Installation of this device It is very popular in places where emergency power outages often occur, as well as where periodic electrical wire breaks are possible.

Sensor with photocells

As you can see, there are several types of devices that can be used to turn on the light in a room without using a standard switch. In this case, the signal to turn on for each product will be different: sound, movement or light level.

Each of these devices has its own technical specifications, advantages and disadvantages. Before choosing a device, make sure that this is the type of device you need. Remember that this pleasure does not come cheap. Therefore, your choice must be balanced.

Purpose of the device

Typically, sensors that are designed to turn on lights are used in different rooms:

• in rooms that are rarely visited;
• they are in demand in warehouses or other premises where it is not always possible to turn on the light with your hands;
• in private homes;
• often installed in rooms intended for transition. For example, today such technical innovations can be found in the corridors of office buildings and government institutions;
• It is rational to install them in garages, in summer cottages, as well as in those rooms where it is not possible to install a standard switch. Usually these are sterile rooms or rooms with increased hygiene requirements.

Installed sensor

In addition, depending on the type of device, it can be used in a variety of situations where its functions are in demand. For example, thanks to the installation of some types of products, after turning off the electricity, the light will remain on for some time, which is very convenient and allows a person to leave the room without any problems.

The use of such products in the home allows you to use energy more rationally, saving and not wasting it. Connecting a sensor will allow you to significantly increase the operating resources of the light sources you use.

Of course, there is not always a need to install a sound recorder for turning lights on/off in a private or apartment building. But if you want to make your home more technologically advanced or just surprise your friends, then the best way what to buy sensor For Sveta, No.

Operating principle

The sound sensor required to turn on the light belongs to the group acoustic mechanisms. The principle of its operation is based on the detection of an acoustic wave by the device. Such a wave propagates throughout the device, penetrating inside. At the same time, he registers any deviations from standard parameters, which arise as a result of the propagation of a sound wave. The wave speed and its amplitude are used as reference points. The wave speed, in turn, is recorded through the frequency and phase indicator.

Any device designed to turn on lighting in a room using an audible signal must be installed in a break in the power line of the lighting device.

Sensor installation diagram

The operation of the device itself follows the following algorithm:

• The device is in the " acoustic control" In this mode, the sensor is able to suppress the sound signal;
• in the presence of a loud acoustic signal, the device picks it up due to a sharp change in the sound background;

Pay attention! The sensor can interpret a door slam, a person’s steps, a door opening, a voice, etc. as a sound signal.

• When a sound wave is detected, the device turns on the light for 50 seconds. During this time, it does not respond to changes in the sound background in the room.

According to this algorithm, the device operates until the next change in the sound background in the room. If it has not registered the acoustic waves, the light will be automatically turned off.

If noise is detected, the operation of the device will be extended for another 50 seconds. This algorithm will be repeated throughout the operation of the device.

It should also be noted that the sound sensor uses piezoelectric materials in its operation. In physics, piezoelectricity is understood as a certain type of electric charge that is formed due to the presence of mechanical stress. Piezoelectric materials, when applied to an electric field of a certain charge, cause mechanical stress. Thus, piezoelectric sound sensors promote the development of mechanical waves using an electric field. Based on these phenomena, the operation of acoustic sensors occurs.

Acoustic sensor

The microphone serves as the receiver of the sound signal. It serves as a converter of acoustic vibrations into the existing alternating electrical voltage.

These microphones come in the following types:

• low-resistance - is an inductor equipped with moving magnets. They act as variable resistors;
• high-resistance - is the equivalent of a variable capacitor.

In addition, microphones can be:

• electret two-terminal;
• three-terminal electret.

But such microphones have somewhat poor signal transmission. To improve their performance, a special amplifier is needed that will pre-amplify the acoustic wave.

Despite the fact that electret microphones are similar to piezo transducers, they differ from them in linear transmission, as well as a significantly wider frequency. This allows the device to process the received signal without distorting it.

As practice shows, this operating principle is very reliable, which guarantees long-term operation of the device. Therefore, you will enjoy this technological device for quite a long time.

With a sensor focused on receiving the audio signal, you optimize the switching process Sveta in your home or in a separate room. Installing the device will allow you to save more, and you will no longer look at your electricity receipts with the same fear.

How to select and install volume sensors for automatic control light
Homemade adjustable transistor power supplies: assembly, practical application

Diagram of an acoustic sensor in amateur radio designs

In the first circuit considered, the sensor acoustic type assembled on the basis of a piezoelectric sound emitter, reacts to various vibrations in the surface to which it is leaning. The basis of other designs is a standard microphone.

This sensor will be effective if the surface it monitors is a good conductor acoustic waves(metal, ceramics, glass, etc.). The acoustic transducer in this amateur radio design is a typical piezoelectric sound emitter from a Chinese multimeter type M830. It is round plastic case, in which the brass plate is placed. On its surface opposite the body there is a piezoelectric element, the outer side of which is silver-plated. Wires come out from the silver plated surface and from the brass plate. The sensor must be installed on the controlled surface so that its plastic body is in good contact with the controlled surface. When installing an acoustic transducer on glass, to increase sensitivity, you can remove the emitter from the housing and attach it so that its smooth brass surface is pressed against the glass.

When exposed to the surface with which transducer B1 is in contact, electrical oscillations are generated in it, which intensify preamplifier and are converted into logical pulses by a comparator on op-amp A1. The sensitivity of the device is adjusted by tuning resistance R3. If the generated voltage appearing in the converter exceeds the sensitivity threshold of the op-amp. At its output, logical impulses are formed that are chaotic in nature.

The logical device is built on the K561LA9 microassembly. The circuit implementation is a typical one-shot RS-trigger circuit, with input blocking. When voltage is applied from the power source, the trigger switches to the single state and remains immune to input pulses for as long as capacitor C2 is charging through resistor R6. Once this capacity has completed charging, the trigger will unlock.

With the arrival of the first pulse from the acoustic sensor, the trigger switches to the zero state. Transistor switch VT1-VT2 unlocks and connects the relay load or siren from the system burglar alarm. (The load is connected in parallel with diode VD2). This starts charging capacitance C3 through resistor R13. While this charging is going on, the trigger is kept in the zero state. Then, it is reset to single and the load is turned off.

To prevent the circuit from cycling due to its own acoustic vibrations created by the siren, there is a C4-R11 chain that will block the input of the logical device and will open it only after a short time interval after disconnecting the load. You can block the logic circuit by pressing toggle switch S1. The structure will return to operating mode 10 seconds after releasing toggle switch S1. The supply voltage U p should be in the range of 5-15 Volts.

Pre-amplification of the signal occurs on the left side of the circuit. VT1 type KT361 or its more modern analogue, to the base of which the signal from microphone M1 follows through capacitance C2, which, together with resistance R4, forms a single-stage microphone amplifier. Transistor VT2 type KT315 is a typical emitter follower and performs the function of a dynamic load of the first stage. The current consumed by it should not exceed 0.4-0.5 mA.

Further amplification of the signal is carried out by a DA1 microcircuit of type KR1407UD2 with low current consumption. It is connected according to a differential amplifier circuit. Therefore, common-mode interference induced in the connecting wires is perfectly suppressed. The common mode rejection factor for input voltages is 100 dB. The signal taken from load resistances R6 and R7 follows through capacitors C3 and C4 to the inverting and non-inverting inputs of op-amp DA1. The signal amplification factor can be adjusted by changing the values ​​of resistances R8 and R9. Resistors R10, R11 and capacitance C5 create an artificial midpoint at which the voltage is equal to half the voltage of the power supply. Using resistance R13 we set the required current consumption of the microcircuit.

The figure below shows the circuit of a simple, highly sensitive sound sensor that controls a load using a relay. An electret microphone is used in the development; when using ECM, a resistor R1 with a resistance of 2.2 kOhm to 10 kOhm is required. First two bipolar transistor are a pre-microphone amplifier, R4 C7 in this circuit eliminate the instability of the amplifier.

After the amplifier on BC182B, the acoustic signal is supplied to a rectifier using 1N4148 diodes and capacitor C5, the resulting constant voltage after the rectifier, it controls the operation of the BC212B transistor, which in turn controls the relay.

Option 2

The circuit is simple and does not require adjustment; the disadvantages include the following: the relay reacts to any loud sounds, especially low frequencies. In addition, unstable operation of the structure was observed at sub-zero temperatures.