Sensor

IR Module

The IR sensor module consists mainly of the IR Transmitter and Receiver, Op-amp, Variable Resistor (Trimmer pot), output LED in brief. IR LED Transmitter. IR LED emits light, in the range of Infrared frequency. IR light is invisible to us as its wavelength (700nm – 1mm) is much higher than the visible light range.

Sound Sensor Module

Sound detection sensor module detects the intensity of sound where sound is detected via a microphone and fed into an LM393 op-amp. It comprises an onboard potentiometer to adjust the setpoint for sound level.

Flame Sensor Module

A flame sensor module that consists of a flame sensor (IR receiver), resistor, capacitor, potentiometer, and comparator LM393 in an integrated circuit. The far-infrared flame probe converts the light detected in the form of infrared light into current changes.

Flame Sensor Module

Thermistor Sensor Module is used to sense temperature and convert it into output signals. Basically thermistor sensors are mostly Negative Temperature Coefficient (NTC), which means NTC thermistors will have their electrical resistance decreased when subjected to an increase in body temperature.

Ultrasonic Sensor Module

Ultrasonic ranging module HC - SR04 provides 2cm - 700cm non-contact measurement function, the ranging accuracy can reach to 3mm.Ensured stable signal within 5m, gradually faded signal outside 5m till disappearing at 7m position.

The modules includes ultrasonic transmitters, receiver and control circuit. The basic principle of work:

• Using IO trigger for at least 10us high level signal；

• The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back.

• IF the signal back, through high level , time of high output IO duration is the time from sending ultrasonic to returning. Test distance = (high level time×velocity of sound (340M/S) / 2.

Gas Sensor Module

The gas sensitive material used in the MQ-2 gas sensor is SnO2, a low electrically conductive material in clean air. When there is combustible gas in the surrounding air, the electrical conductivity of the sensor will increase with the higher intensity of the combustible gas. Here, we can convert the changing electrical conductivity into output signal by building a simple circuit.

Metal Detector Module

A metal detector is an instrument that detects the presence of metal nearby. Metal detectors are useful for finding metal inclusions hidden within objects, or metal objects buried underground. They often consist of a handheld unit with a sensor probe which can be swept over the ground or other objects. If the sensor comes near a piece of metal this is indicated by a changing tone in earphones, or a needle moving on an indicator. Usually the device gives some indication of distance; the closer the metal is, the higher the tone in the earphone or the higher the needle goes. Another common type are stationary "walk through" metal detectors (see § Security screening below) used at access points in prisons, courthouses, and airports to detect concealed metal weapons on a person's body.

The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal is close to the coil, eddy currents will be induced (inductive sensor) in the metal, and this produces a magnetic field of its own. If another coil is used to measure the magnetic field (acting as a magnetometer), the change in the magnetic field due to the metallic object can be detected.

The first industrial metal detectors were developed in the 1960s and were used extensively for mineral prospecting and other industrial applications. Uses include detecting land mines, the detection of weapons such as knives and guns (especially in airport security), geophysical prospecting, archaeology and treasure hunting. Metal detectors are also used to detect foreign bodies in food, and in the construction industry to detect steel reinforcing bars in concrete and pipes and wires buried in walls and floors.

Motion Sensor Module

The Passive Infrared Sensor (PIR) sensor module is used for motion detection. It is used to sense movement of people, animals, or other objects. They are commonly used in burglar alarms and automatically-activated lighting systems.

Alcohol Sensor Module

This module is made using Alcohol Gas Sensor MQ3. It is a low cost semiconductor sensor which can detect the presence of alcohol gases at concentrations from 0.05 mg/L to 10 mg/L. The sensitive material used for this sensor is SnO2, whose conductivity is lower in clean air.

Water Level Sensor Module

The water level sensor (sometimes called a leak detection sensor). Included are wiring diagrams, code examples, pinouts, and technical data. This sensor connects to an an analog input pin and provides an integer value generally from 0 to 500 indicating the level of water. When used with a digital pin and a pull up resistor, it can give an indication of the presence of water without reporting its depth.

RFID Sensor Module

Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder, a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods.

There are two types of RFID tags:

• Passive tags are powered by energy from the RFID reader's interrogating radio waves.

• Active tags are powered by a battery and thus can be read at a greater range from the RFID reader, up to hundreds of meters.