Below will answer the questions of DMX512.

I has question of DMX512 for you，this is roughly thought as follows:
I will be do a system that is simply control the lights products with MCU to process a signal of DMX512。so that there are several lamps can be terminal. A very simple system, a controller, a few lamp terminal。The controller sends a 512 signal to control each lamp state。Now 512 protocol is based on RS４８５, is half duplex, how to identify the data packets belong to the lamp terminal。

Flexible LED lamp(LED strip) belt adopted a flexible circuit board
Flexible LED lamp belt is used in flexible circuit boards, which is we usually refer to the FPC. FPC itself as soft。Thin (generally having a thickness of 0.15 ~ 0.2mm), so the great difficulty when assembling.

1, difficulty of the circuit board print
Because FPC is too soft, too thin, so positioning became a problem. Previously, many people are using double-sided tape to fix, but the shortcomings that the printing job is finished after the double – sided tape is difficult to take down, affecting production efficiency and quality. Later someone with a jig, using in the fixture to achieve a fixed position, so although using fixture to progress than some, but because of the use of edge location is not very accurate (FPC is too soft, it will moves), will also affect the quality. Later on the use of self-stick silicone to make the jig, efficiency and quality are guaranteed.

2, the patch of difficulty
Because the LED lamp belt are relatively long ，most is 50CM long, the shortest has 30CM, SMT machine stroke are not enough，if the pasted half back again with the other half of the words, it will affect the efficiency, and because mobile positioning, so stick Precision sheet is also not guaranteed.

3, the difficulty of reflux
Because FPC lights with long, with thin, and reflux temperature lead-free solder paste is also very high, which will result in overheating and warping FPC, the impact of LED placement position thus affecting the quality of products, and if the reflux temperature down and reach the melting point of solder affect welding results.
The general practice is to use a jig, there have place of fixture hole in the LED below, so that the reflux temperature of the heating for the needs of the welding place, and its places due to fixture barrier and lower the temperature, no warping effects of welding accuracy.

4, the difficulty of repair
Because the FPC is thinner,so the perseverance of high temperature relatively short time. LED lamp belt if adverse goods need to rework the words, then you need to pay attention to the temperature of the soldering iron (not more than 300 degrees) and welding time (not more than 5 seconds), otherwise it will cause FPC blistering, soak the entire product is scrapped. So when maintenance is critical to control these two aspects, maintenance personnel Skill to master is also critical. These are some tips and considerations LED lights with the chip assembly process。

1, overview
The function positioning stage is: to held various meetings, and can also be To give a performance or shows.

2, the scope of design:
According to architectural design plan of center stage light system designed of center stage divided into as follows:
1)Stage light

2)The top stage light

3)Electric hanger stage lighting, stage along the screen, lintel curtain, vertical curtain, two curtain, screen frame, empty spare rod up and down for maintenance for the scene, need be designed.

3)design principle:
Light system project, in whole process of the implementation scheme and design schem. Light configuration, pay attention to actual effect, to achieve the best price performance ratio。which is one of the design principles. Combining the function orientation, the input of funds, to ensure the effect and leave room for expansion, is the design principle of the two.
4, Description of stage lighting plan
1) stage light:
The stage surface light by 6 PCS(2*36w) stage soft light component. Surface light main function is light to the front of the stage, is the basic lighting figures and table scenery. According to the need for all kinds of stage. with light volume through simple control timely(by LED controllers), the lamp is 2 PCS 36W/U lamp tube.average illumination lamp for 3600K, soft light, color temperature lamp eye open quasi, almost no harsh feeling, is the essential source of photography. Is the first choice of lamps and stage and studio.
2) The top light of stage,
Over the traditional stage is almost always a curtain lamp and PAR to compose. Even the lamps in the large stage venue with a inconceivability。such lamps in use not only the low illumination; and more of a risk to the safety!If used for a long time, but also make the stage suspension brought into light heat, A new three color cold light lamp will be completely resolved in the past can not solve the problem.
Three color cold light lamphas 5 major characteristics:

1, long service life: 10000 hours service life of the lamp, isten times than thermal light bulb, if use 10 hours per day calculated, does not need to replacement lamp for three years.

2, low temperature: tube surface temperature is low, the irradiated object almost no warming phenomenon， is the real meaning of “cold” light, so completely solves the stage due to high temperature phenomenon.

3, small power: the average power of each lamp in between 72~330W, power-saving 70% above than the heat light source lamp, a small stage or power consumption does not exceed 2KW.

4, color temperature quasi: lamp color temperature to 3200K, the upper and lower error only less than 1.5%, can fully meet the requirements of light source technology . The color index is 95, with good color reduction. Completely solved due to temperature is not stable and cause the announcer facial partial color phenomena caused by the past with the heat lamp light source.

5, soft light: light uniform, soft, stager thinks generally, eyes feel comfortable, no glare phenomenon.

The layout design of the lamp according to the construction plan are provided, namely placed 8 pcs three primary color lamps on the stage at the top

In automatic control system, MCU to realized a music control of automatic and intelligent。In automation technology control system, the use of MCU realization of the music lighting control automation, intelligent, and without the need of human intervention then automatically adjust a better feeling with light musical transformation, to achieve the integration of sound and light.
This system is only a simple design idea, it’s just a model, hasn’t directly put into use.But the success of this system shows that the design can be realized, and as long as the appropriate hardware and software modifications may be applied to many fields. For example, you can design LED display, LED lighting decoration series products etc..LED display series can be: LED variable message signs, LED variable speed limit signs, LED lane controller, traffic lights, countdown display for licensing fees, card, canopy lights, and various series of indoor and outdoor LED display. Making LED decorative lighting series are: used in bars, dance halls, nightclubs, clubs, leisure centers and other places of entertainment LED color curtain, LED color, LED color ground smallpox, the external walls of buildings (or profile) night lighting and decorative wall display etc.. Here’s to the bar display screen as an example to analyze how to improve the system will be applied to reality. Prospects for the development of a system application and development 1.1 system。First, the display part with full-color LED instead of uncolored LED, with a MCU to control full-color LED display screen will become DISCO upscale bars, night show, the most advanced lighting products market. Due to the application of the MCU technology and digital signal processing technology, , so different from the ordinary decorative lighting, is also different from traditional laser stage lights. It appears on the traditional decorative lighting night show presented a great challenge, but also make decorative lighting night show entered a completely new era.

By appropriate control, it can produce a variety of dynamic screen effect according to the melody, rhythm and shade and color changes and, express a kind of secret dream away, dazzling mysterious, gorgeous colorful background lighting. DISCO thus caters to upscale bars, night show  arena has requirements for lighting background, will become the latest highlights of the current night show  decoration.

MCU control of full color LED display screen has the advantages:

1, a great variety of colors, 256 gray levels, more than 1670 million colors let you choice;

2, To make realistic— realized a music control, can be controlled through a MCU according to DJ playing disc and live music control LED display and wall led changes, to realized the music and light seamless connection, let the light and sound volume capacity in one;

3, well-designed control software, a friendly user interface, and with multi-window multi-page display, shortcut keys, make DJ easy deployment of sound and light show wonderful, fantastic changes; development of such applications to adapt to the times , keep synchronous development with the advanced technology in future, there will be more development prospect.

1. Explosion-proof lamp shall be provided a permanent and eye-catching logo “Ex” with embossed or concave pattern。 A prominent place in the shall to be provided nameplate. Warning signs should be clearly visible, set in propriety place. Such as “off the power after opening the lid” warning signs shall be install at openings nearby.
2 because of explosive dangerous location is often associated with the presence of corrosive gases, so the symbol of explosion-proof lamp shell shall be with thickness not less than 1mm (small lamps and lanterns thickness not less than 0.5mm) bronze, brass, stainless steel or corrosion resistance than other material made。 Should also be reliable fixed, not easy to fade or fall off.
3,The methods of test marker durability is: after using water-soaked cloth graze 15s to be dry, and then using gasoline soaked cloth graze 15s, visual inspection, signs should be clear, not falling.
4. Content of nameplate signs should include:
A) explosive proof mark.
B) basic signs: including product name, model number, manufacturer name, registered trademark, manufactured date.
C) performance safety signs include: rated voltage, current, nominal frequency, light source power , quantity, allowable ambient temperature (the range is -20 ~ +40 ℃ not standard), the specific application of environmental labels (such as to apply only one kind of explosive gas mixture of products, shall be marked with the name and molecular formula of combustible gas), luminaire classification symbol (such as “digital) and so on.
D) explosion-proof certificate number, that the product has the explosion-proof test stations officially tested by. Some products are explosion-proof certificate No. with the “X” symbol, which shows that this kind of product can only be used in some special security conditions of use, should be clearly marked to indicate the conditions prescribed in the lamp shell or product specification. Special security conditions there are many types, users see the proof certificate number after the “x” symbol, they should pay attention to understand the kinds of products to find exactly what special security conditions, in order to properly operate the installation process to avoid danger.
D) annotated. In addition to the mark, in order to ensure the correct installation details required, use and maintenance of detail required, shall be in the lighting, or the built-in ballast and lighting products provided with the manufacturer’s instructions are given. For example:
A allowable working position of explosion-proof lamp, explosion-proof lamps are only allowed to use some installed in a position or a certain angle range, this is because the position the change, the heat distribution explosion-proof lamps surface and the maximum surface temperature will change, the reason for the explosion-proof lamp position limits, the main the reason is that in order to control the maximum surface temperature, not to let the temperature over explosion-proof lamp itself marks, brings dangerous temperature. Therefore, the explosion-proof lamp installation position limit must be clear.

An safe explosion proof LED lights, belong to the electric equipment of specially industry。Mainly to resolve the lighting problem。Which include a lamp shell， lamp shade , inner light , battery ,and set in switch lamp shell surface。Which is feature：the luminous is high power LED module。the input driving voltage is widely between the luminous body and battery ;widely voltage includes: constant current chip, battery and constant current mode together to comprises a power module。LED module is connected to the constant current chip, power supply module and the LED module encapsulation together; between the lampshade and lamp for ultrasonic welding。a switch connected between the chip and the battery, and a constant current waterproof switch,It uses LED low heat characteristics to achieve proof intrinsically safe level, and long battery services time of LED light source; LED con be maintain a constant brightness in full charge and discharge stage; cooling device is arranged in the lamp shell, which can be effective heat dissipation, and to ensure the stability, suitable for coal mine, petroleum, railway, flood control etc. a variety of lighting industry.

Three-color LED driving design applications typically by adjusting current to reach the balance and maximum brightness values。In general,we using most easiest and optimal way to design the full color display technology。White balance is most single for check the combination of color。The three primary colors are red and green and blue ， the three primary colors are mixed according to brightness proportion。blending after human eyes feel is pure white. Earlier CRT TV to the now LCD liquid crystal display are so constituted, LED course will mature technology copying.Chromaticity coordinates LED red, green, blue is unable to achieve the full effect of the chromatogram due to process and other reasons, and the control of the primary colors including a deviation of the brightness to achieve the white light, called the match color. When performing full-color LED display before，in order to achieve optimum brightness and the lowest cost, you should try to choose RGB luminous intensity of roughly 3: 6: 1 ratio of LED devices composed of pixels balance requires the synthesis of the three primary colors in the allocation value synthesis ，it is remains the same for pure white.merely a LED is very difficult to achieve, in order to solve this problem, in general， IC will set the current size, convenient for different batches of LED can be to achieve the same white light effectWe have synthesized color called original color; Application of the red, green, and blue color is primary called, three vertices is an ideal primary color wavelength in the chromaticity diagram。if there are deviations, the color synthesized area will be reduced, the triangle will shrink in the spectral table,from a visual point of view, the color deviation will not only reduce, as shown below.LED emitted Red, green, purple and blue light according to their different wavelength characteristics ，can be roughly divide into pure red, orange, orange, orange, yellow, green, pure green, green, blue-green, blue, violet, etc., orange , green, blue and purple , pure red, pure green, pure blue price is very cheap . Three primary colors of green is most important, because the green occupy 69% brightness white and color at the center of the transverse row of the table. Therefore when the relationship between the color of purity and price trade-offs between, green is the object of important consideration.

29,what is the static driver? What is the scan driver? What is the difference between the static driver and scan driver?
From the driver IC output pin to implement the pixel “point to point control” is called static drive; from drive IC output pin to implement the pixel “point to control the column” called the scanning driving, it needs the row control circuit; from the drive plate can clearly see: static drive not the need for control circuit, high cost, but the display effect is good, good stability, brightness loss is smaller; scanning drive need the row control circuit, but the cost is low, shows effect is poor, poor stability, brightness loss;

30,what is a constant current driving? What is the constant voltage driving?
Constant flow refers to the IC driver working of allows environment, the design of a constant predetermined output
current value; constant pressure refers to the IC driver
working of allows the environment, the design of a constant predetermined output voltage value;
31, what is the nonlinear Calibration?
If computer output without Verify digital signal is displayed on the LED screen will appear color distortion, so at the system control circuit, the computer will be output a signal that is via nonlinear function to counter a result, and it’s display needs.the signal will be the original computer signal output by a nonlinear function to calculate the display needs, due to the nonlinear relationship between signal, so, we often call it as nonlinear correction; due to non-linear relationship between the front and rear signals, so we often call for nonlinear Calibration;

32, what is the rated working voltage? What is the working voltage? What is the power supply voltage?
Rated working voltage refers to the voltage value during normal operation ; work with electrical voltage is within the rated voltage range, voltage value during normal operation; supply voltage divide into AC and DC supply voltage,
33,what is the color distortion?
Refer to the same object in nature and displayed on the screen, both for human sensory visual difference;

34, what is the synchronization system, what is the asynchronous system?
Synchronous and asynchronous is relative to the computer, so-called synchronization system,refers to the control system of LED display screen shows the contents and computer display the contents is asynchronous to show out. asynchronous system refers to a computer edited to display data previously stored in the display control within the system, the computer shut down will not affect the normal display LED display, this control system is asynchronous system;

35,what is the blind spot detection technique?
Through the PC software and hardware, can display the blind spot (LED open circuit and short circuit) is detected, and the formation of the report told LED screen management, so a technique called blind spot detection technique;

36, What is the power supply detection?
Through the PC software and hardware,can be detect the work status of display power supply, and the formation of the report to information of LED screen body management, so a kind of technology is called power detection technology;

37: what is the brightness detecting? What is the brightness adjustment?
Brightness brightness detection refers to the LED display locate on the environment brightness, with light sensor, will display the environmental brightness is detected, the detection method called brightness detection; brightness adjustment that refers to a LED display screen brightness, the detected data back to the LED display control system or control computer, then according to the brightness adjusting screen, called the brightness adjustment;

38: what is the real pixel? What is the virtual pixel? The dummy pixel is divided into several? What is the pixel sharing?
Real pixel refers to physical pixels on the screen and the display pixels is 1:1, display the actual number of points, how many points can only display the image information;     Refers to physically dummy pixel is the number of pixels displayed on the display and the actual number of pixels is 1: N (N = 2,4) of the relationship between the image pixels can be displayed twice or four times more than the actual pixels of the display;Virtual pixel in accordance with the virtual control can be divided into: virtual and hardware virtualization software; divided according to multiple relationship: two times and four times the virtual virtual, according to the row of lights on the way to divided into: 1R1G1B virtual and 2R1G1GB virtual;

LED basic knowledge quiz(part 2)
14,what is the dual color, pseudo color, full-color display?
With different colors of light-emitting diodes can be composed of different screen, double color is red, green or yellow green two colors,pseudo color is red, yellow, blue consisting of three different colors,full color is red , pure green, blue consisting of three different colors;

15, What is the luminous intensity?
LED display light intensity emitted per unit area, the unit is cd / ㎡, it simply is the light intensity emitted by one square meter display;

16: what is the level of brightness?
The entire screen brightness at the lowest to the highest brightness between manual or automatic adjustment of the series;

17: what is the gray level?
Under the same brightness level, the display technology from the darkest to the brightest among processing stages;

18: what is the maximum brightness?
Under certain environmental illumination, LED display primary colors at the maximum brightness and the maximum gray scale level;

19, What is PCB?
PCB is (Printed Circuit Board abbreviation) printed circuit board;

20, What is BOM?
BOM (Bill of material abbreviation) Bill of material;
21, what is the white balance? What is the white balance adjustment?
We said white balance, refers to the white balance, i.e., R, G, B three color brightness of 3: 6: 1 ratio balanced;

22,what is the contrast?
Under certain environmental illumination, ratio of LED maximum brightness and LED background brightness;adjust R, G, B three color brightness ratio and the coordinates of white, called for white balance adjustment;
23, what is color temperature ?
The color and the blackbody of source emitting light to Radiation light is same at a temperature
temperature of Blakbody called the color temperature of light source.

24, what is change the frequency of frame?
Screen information update times in unit time.

25,what is the refresh frequency? ;
Display information is repeated time by display screen.

26,what is the view point? What is a perspective? What is best viewing point?
Viewing point is the brightness of the viewing direction to decrease the brightness of the LED display of half the normal direction, and the angle formed with a plane two observation direction and the normal direction of the. Divided into horizontal and vertical perspective;      Perspective is just to be able to see the direction of the display image content on the display, and the angle formed by the normal display;The best viewing point is just able to see the full content on the display ,meanwhile without color cast, the clearest image content with the normal to form an angle;

27, what is the best line of sight?
The best viewing point is just able to see the full content on the display ,meanwhile without color cast, the clearest image content position relative to the vertical distance is the best line of sight

28, what is a point out of control? Several minutes?
Pixel lighting and control requirements do not match; out of control points are divided into: blind spot (or called dead), often highlights (or dark), flash point;

LED basic knowledge quiz
1,what is LED?
LED is light emitting diode , display industry call”LED” especially point to can emit light LED.

2, what is pixel?
It is minimum light luminous on led display. , meanings is same with the ordinary computer display.

3, what is pixel spacing”?
distance between one center of pixel to center of pixel

4, what is LED display module ?
Multi-pixel and special circuit to compose a minimum LED display, meanwhile the   structure is independent, typical module has “8 x 8″, “5 x 7″, “5 x 8″ etc.,

5, what is DIP?
DIP is Double-in-line Package acronym, dual in-line assembly;

6, What is SMT? What is the SMD?
SMT is Surface Mounted Technology acronym, it’s a kind of technology and technique most popular on the electronic assembly industry’s.   SMD is Surface mounted device acronym

7, what is LED display module?
To determined by circuit and installation of the basic unit, with display function. Through simply install to achieve the base unit function.

8, what is LED display screen ?
Through certain control method, the display screen is composed of LED array.

9, what is the inserted lamp module? What are the advantages and disadvantages?
Refers to the DIP package light the lamp foot through the PCB board, the tin filled in the lamp holes with welding, this technology module is call “inserted lamp module”; the advantages is: large visual angle, high brightness, good heat dissipation; disadvantage is the pixel density;

10, what is the Surface mount? What are the advantages and disadvantages?
Surface mount is also called the SMT, SMT package light through the welding process of welding on the surface of the PCB, the foot of lamp not through the PCB board, made ​​by this process is called surface-mount module; advantages are: the perspective of large, display image soft, large pixel density, suitable for indoor viewing; drawback is that the brightness is not enough, the heat dissipation is not good enough;

11, what is the sub surface mount module? What are the advantages and disadvantages?
Sub surface mount is a product between DIP and SMT, the LED lamp package surface like SMT, but its positive and negative pin and DIP, production is through the PCB board to welding, the advantages are: high brightness, good display effect, the shortcoming is: complex process, difficult to repair;

12, What is the 3-in-1? What are the advantages and disadvantages?
Refers to the R, G, B three different colors of LED chip package in the same gel; advantages are: the production of simple, good display effect, the disadvantage is: spectrophotometric color difficult, high cost;

13, What is three and one? What are the advantages and disadvantages?
refers to the R, G, B three independent SMT package tied together in a certain light vertical spacing, so that not only has the 3-in-1 All individual advantages, but also to solve the shortcomings of 3-in-1;