The advent of the new technological revolution, the world began to enter the information age. To get a lot of human senses can not directly access the information, there is no suitable sensor is not possible. IoT makes artificial intelligence a reality. The Internet of Things provides off-the-shelf sensors that provide more meaningful ways to perceive the physical world, thereby allowing artificial intelligence to "survive." Sensors give artificial eyesight to see the world with "eyes", giving them a "good ear" that gives artificial intelligence "a keen sense of things." In many ways, sensors are giving artificial intelligence the ability to be "superhuman."
一、the ultrasonic sensor
Ultrasonic sensors are transducers that convert ultrasonic signals into other energy signals (usually electrical signals). Mainly used in robot barrier. The most common sensor is the HC-SR04. The price is 2-5 yuan, very cheap.
The principle of operation is to input a trigger signal of at least 10 μs to the TRIG pin first. Eight 40 kHz cycle levels will be generated internally and the echo will be detected. ECHO outputs a high-level echo signal once an echo signal is detected. The pulse width of the echo signal is proportional to the measured distance. The distance can thus be calculated by transmitting the signal to the received echo signal interval. Formula: Distance = High time * Sound speed (340M / S) / 2.
二、the temperature and humidity sensor
Temperature and humidity sensor is only one of the sensors only, the air temperature and humidity through a certain detection device, measured the temperature and humidity, according to certain laws into electrical signals or other forms of information required to meet the user demand. The most common sensor is the DHT11.
DHT11 is a calibrated digital signal output temperature and humidity sensor. The accuracy of humidity + -5% RH, temperature + -2 ℃, humidity range 20-90% RH, temperature 0 ~ 50 ℃.
三、infrared sensors
Infrared sensor is a can detect human or animal infrared and output electrical signals sensor. The most common sensor is the HC-SR501.
HC-SR501 is an automatic control module based on infrared technology. It adopts LHI778 probe design. It has high sensitivity, high reliability and ultra-low voltage operation mode. It is widely used in various automatic induction electrical equipment, especially the battery-operated automatic control products.
四、the raindrop sensor
Rain sensor is a sensing device, mainly used to detect whether it is raining and rainfall size, and is widely used in automotive automatic wiping system, intelligent lighting system and intelligent sunroof system. The most common sensor is the YL-83. The price is 4-5 yuan, very cheap.
How it works: Connected to the 5V power supply light is on, there is no water drop on the sensor board, the DO output is high, the switch light is off, a drop of water is dripped, the DO output is low, the switch indicator is on, , And returned to the output high state. AO analog output, you can connect the microcontroller's AD port drops in the above rainfall. DO TTL digital output can also be connected to the microcontroller to detect whether there is rain.
五、flame sensor
Flame sensor is a robot dedicated to search for the source of fire sensor, of course, the flame sensor can also be used to detect the brightness of light, but the sensor is particularly sensitive to the flame. Flame sensor uses infrared light is very sensitive to the characteristics of the flame, the use of special infrared receiver to detect the flame, and then the brightness of the flame into high and low level signal changes, input to the central processor, the central processor according to signal changes Make the appropriate procedures. The most common is the flame sensor. The price is 2-5 yuan, very cheap.
working principle:
1, the flame sensor is the most sensitive to the flame, is also a response to ordinary light, generally used for flame alarm and other purposes.
2, a small board output interface can be connected directly with the microcontroller IO port
3, the sensor and the flame to maintain a certain distance, so as to avoid damage to the sensor temperature.
六、 the sound sensor
The sound sensor acts like a microphone (microphone). It is used to receive sound waves and display vibrating images of the sound but not to measure the intensity of the noise. The sensor has a built-in sound-sensitive condenser electret microphone. The sound wave makes the electret film in the microphone vibrate, resulting in the change of the capacitance, resulting in a slight voltage changing correspondingly. This voltage is then converted into a voltage of 0-5V, which is accepted by the data collector via A / D conversion and sent to the computer.
Work is mainly used for voice control module. Sound control switch in the corridor generally use this module switch lights.
七、gas sensors
A gas sensor is a converter that converts a gas volume fraction into a corresponding electrical signal. The probe uses a gas sensor to condition the gas sample, usually including filtering out impurities and interfering gases, and drying or cooling the instrument display. A gas sensor is a device that converts information such as gas composition, concentration, etc., into information that can be used by personnel, Carling instruments, computers, etc.! Gas sensors are generally classified as chemical sensors, although this classification is not necessarily scientific.
Common 9 gas sensors include:
MQ-2-smoke gas sensor
MQ-3 - Alcohol sensor
MQ-4 - methane sensor
MQ-5 - LNG city gas sensor
MQ-6 - Isobutane propane sensor
MQ-7 - Carbon monoxide sensor module
MQ-8 - hydrogen sensor
MQ-9 - carbon monoxide combustible gas sensor
MQ-135 - air quality detection sensor
八、 brightness sensor
Brightness sensor, refers to the feeling of brightness and converted into a usable output signal sensor.
Detection of ambient brightness and light intensity.
