LED display basics
Modern society has entered the information age, information dissemination has become more and more important, and people's demands for visual media are getting higher and higher, requiring the media to reflect quickly, realistic (real-time), eye-catching (colorful, lifelike), The screen is super-large and powerful. In recent years, with the rapid development of microelectronics technology, automation technology and computer technology, the semiconductor manufacturing process has become more and more mature, resulting in smaller and smaller LED display points and higher resolution. The three primary colors (red, green, and blue) of the display light can be integrated into one body to achieve a full-color effect, so that the application range of the LED display screen is expanding.
LED display features
LED is the abbreviation of Light Emitting Diode. It is a widely used material for illuminating display in the field of optoelectronics. Different materials can be used to produce red, green, yellow, blue and other colors under certain conditions. LEDs have the following characteristics, making them Become the material of choice for making large screens:
â—†High brightness, the brightness of outdoor single lamp is close to 6,000mcd;
â—† Low power consumption and high photoelectric conversion efficiency;
â—†Long life, LED life is up to 200,000 hours or more;
â—† fast response, ns level, no residual ash;
◆ Low voltage and low current drive, easy to interface with the computer. ·Characteristics of LED display
Compared with other large screen displays, LED displays have the following characteristics:
â—†The screen size can be large or small, and the maximum can be 500m2.
◆The viewing angle is large, the indoor screen viewing angle is greater than ±80 degrees, and the outdoor screen viewing angle is greater than ±60 degrees.
â—†The line of sight can be adjusted by selecting products with different diameters and different dot pitches. It can be as small as several tens of centimeters and as large as several hundred meters. The minimum diameter of pixels can be 1.9mm.
â—†Flexible configuration, simple to digital display, complex to full-color video screens have different types of products to meet the requirements, indoor and outdoor have corresponding products.
â—† Easy to interface with computer, support software rich.
At present, other large-screen displays mainly have the following types, and their performances have their own advantages.
Screen type advantages and disadvantages
Magnetic flaps have low power consumption and low response speed, making it impossible to display video and high failure rate
TV wall full color with separate lines, low brightness, not suitable for text, can not be used outdoors
Projection full-color picture has low brightness and low brightness, can not be used outdoors, and has poor definition (uneven picture is uneven)
CRT full color cost, high power consumption, area can not be too large
PDP full color picture is delicate and costly, the angle of view is small, and the area cannot be too large
1.3 classification of LED display
1.3.1 According to the application site classification, depending on the application site, the LED display can be divided into indoor and outdoor.
The indoor screen is mainly used indoors. In the production process, the light-emitting die is first made into a dot matrix module (or digital tube), and then the module is spliced ​​into a certain size display unit board. According to user requirements, the display unit board is basically used. The units are spliced ​​to the size required by the user. According to the size of the pixel, the indoor screen is divided into Ф2, Ф3, Ф3.75, Ф4.8, Ф5, Ф8, Ф10, and the like.
What is 2.4g wireless module?
2.4g line module operating frequency in the range of 24400-2484mhz, can communicate through the scanning protocol, air rate up to 1Mbps, output power up to +4dBm, the module has the advantages of low power consumption, cost-effective. Movingcomm's current 2.4g antenna modules are: IOT04, IOT05, IOT09, IOT18, IOT60, etc. Users can choose a variety of modules with a transmission distance of 50-500 meters according to cost considerations.
Second, the role of 2.4g wireless module
Function 1, for the formation of a star topology wireless communication network, and must be a multi-point star topology, some extraordinary places need wireless communication. On the one hand, the transmitting and receiving module is cheap, and the cost of forming the star topology is relatively low. On the other hand, the transmitting and receiving module can adopt the modular design, which is small in size, easy to use and easy to integrate. For the wireless network with low communication speed and close distance, the transmitting and receiving module is very practical.
Function 2, for wireless multi-channel (parallel) control. Such as complex remote-controlled robots, some places require multi-channel (parallel) control. One method is to use the receiving module to directly connect to the decoder, and then connect to the relays and other electronic components to drive the subsequent controlled object; the other method is to use the receiving module to connect to the single chip microcomputer, and after the data is disposed of, the single chip microcomputer is connected to the relays and other electronic components to drive the subsequent controlled object. Usually a pair of transmitting and receiving modules can achieve up to six parallel wireless control, if the required number of channels is greater than six, you can use multiple pairs of transmitting and receiving modules, and work at the same time to meet the actual needs.
Function 3, used for general serial port, RS232 antenna data transmission, there are usually many control instruments and equipment using serial port, and communication with these devices must meet the requirements of serial port. In some extraordinary places, when the industrial control site must use the antenna transmission mode, it is natural to choose the transmitting and receiving modules mentioned in this article, but it must be explained here that to use this communication mode, the corresponding software must be prepared at the transmitting end and the receiving end respectively to achieve the conversion of file formats, in order to achieve the purpose of wireless communication, if the communication system is full-duplex. It can be achieved by using two pairs of transmitting and receiving modules, working simultaneously.
Third, 2.4g wireless module application field
2.4G wireless module is widely used in wireless health sports products, wireless mouse and keyboard, product information push, wireless remote sensing, wireless ranging system, alarm security system, smart home, toy control, tire pressure monitoring and other fields. With the 2.4G wireless module, all the whole house wireless smart home can be linked together, you can control all the smart home devices through the link of the network, and then you can control the switch of all the whole house wireless home, adjust the brightness of the lamp, adjust the rise and fall of the curtain, etc., through the continuous innovation of technology, The whole house wireless smart home can be controlled by a small white robot voice, can be controlled by a smart scene panel, can be controlled by sensors and so on.
Four, 2.4g wireless module how to choose antenna
In general, the 2.4g wireless module requires an impedance of 50 ohms, a red wire used with 2.4g, a 2.4g folded rod antenna, a 2.4g gold-plated straight head rod antenna, a 2.4g gold-plated elbow rod antenna, and a 2.4g small suction cup antenna. These antennas are special antennas designed for 2.4g wireless communication system, antenna standing wave ratio performance is good, small size, clever structure, easy installation, stable performance, with good anti-vibration and aging ability.
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Shenzhen MovingComm Technology Co., Ltd. , https://www.movingcommiot.com