Guide to Buy Wireless Keyboard for Dell Laptop in Crowberry

Guide to Buy Wireless Keyboard for Dell Laptop in Crowberry

2022-03-05
Crowberry laptop replacement parts
29

On this page, you can find quality content focused on wireless keyboard for dell laptop. You can also get the latest products and articles that are related to wireless keyboard for dell laptop for free. If you have any questions or want to get more information on wireless keyboard for dell laptop, please feel free to contact us.

Crowberry laptop repair parts never stops to innovate wireless keyboard for dell laptop facing the highly competitive market. We partner with leading raw material manufacturer and select high-precision materials for production. They prove to be of significance to the long-time stability and premium performance of the product. The R&D department works on breakthroughs that will bring value to the product. In such a case, the product is updated constantly to meet market needs.Crowberry laptop replacement parts products have helped us to gain greater revenues in recent years. They are produced with high cost-performance ratio and appealing appearance, leaving a deep impression on customers. From the feedback of customers, our products are able to bring them increasing benefits, which results in the sales growth. Most customers claim that we have been their top choice in the industry.At Crowberry, we promise that we provide the most considerate shipping service. As one of the most reliable partners of our freight forwarder, we guarantee all products like our wireless keyboard for dell laptop will be delivered to you safely and completely.
more products
recommended articles
FAQ
A Good Quality of Laptop Keys for Sale
A Good Quality of Laptop Keys for Sale
Why laptop keys for sale?It is so easy to make mistakes when using your laptop. A good laptop will be able to be changed in no time. Laptop can be very dangerous if you do not take good care of it. The key to making sure that your laptop is working well is to have a clean and neat notebook. If you use your laptop often, it is important to keep it clean and tidy. The right way to clean your laptop is to use a cleaning solution that will help you get rid of any dirt that might be stuck on the screen.The first key to success is an effect. An effect is something that affects someone or something. It can be positive or negative. When you have an effect it will affect people and things around you. If you have an effect it will cause a reaction. You can create an effect by using a word that means something. A good example of an effect is using a name that means something. The key to success is an effect. An effect is something that affects someone or something. It can be positive or negative. When you have an effect it will cause a reaction.When you need to sell your laptop, it is best to sell your laptop keys for sale instead of having to spend time cleaning them. When you have used your laptop for a long time, it is easy to get tired of using it. A laptop key for sale is an investment that you can't just throw away.Most of the time, people don't know what to do with their laptop or desktop computer. People who have an internet connection use it for work, and sometimes they use it for play. They may use it to access online games, check emails, watch movies, and many more. When you use your laptop or desktop computer for work, you need to make sure that you have the right key for the keyboard that you use. If you don't have the right key for the keyboard, you will not be able to use your computer properly.laptop keys for sale featuresWhen you are looking for a laptop, laptop is the only word that will come to your mind. I'm sure that many people are looking for a laptop. The truth is that there are so many different types of laptops available today. They can be made of any type of material, such as carbon, leather, etc.It is important to choose the right laptop key for your needs. When you buy a laptop, you should check that the laptop key for your computer is compatible with your computer model. The key for your computer model is the device that controls the functions of your computer. If you have an older computer, you may not be able to find the right key for your computer model. So you should go to the manufacturer's website and see if they have a list of compatible laptop keys for your computer model. After you have found the laptop key for your computer model, it is important to get it working properly.You can't use your smartphone as a remote control for your computer. It is not an essential feature of a laptop. You can use your smartphone as a remote control for your computer. The same goes for any other device that you have in your home. Laptop has no key to be used as a remote control for your computer. Laptop does not have any key to be used as a remote control for your computer. If you want to use your smartphone as a remote control for your computer, you need to use it as a remote control for your computer.When choosing a laptop, it is important to take into account the size of the screen, and to consider the number of screens that will be required to make the computer work. Some laptops are very small, so it is best to have more than one screen. The first screen should be smaller than the next screen. It is better to have more than one screen so that you can see more content on the screen. For example, if you have two screens, you will need to use two keyboards.Details of laptop keys for saleThis is what people who work in an office think about when they hear the word laptop. That is because laptops are not usually called laptops, but rather laptops. The key to this kind of blog is that it uses keywords and doesn't just describe the keyboard in a positive way. A good example of this kind of blog is 'How to choose the right type of laptop for you.With a click of a mouse, you can have your laptop in no time. The key to success is simple: when you use the keyboard to type, it will be as easy as pressing a button. A good laptop keyboard will make typing a lot easier. It will make it much easier to type and also make it much easier to remember. When you use the keyboard, it will be as easy as pressing a button.This computer key is an EOL key that will be sold by me, it is very hard to find and if you need to buy it, I recommend you go to my site. You can find me at www.TheLaptopGuy.com.When you are done typing this, then click here to see more examples of good content. I would say that the first few lines of this blog should look like this 'It is easy to type with your keyboard and don't need to type in long letters. There are lots of apps that will make it easier to type and there are also many websites that will make it easier to type. So when you are done typing this, then click here to see more examples of good content.There are no reviews for this product. There are no videos available for this product. There are no articles available for this product. There are no videos available for this product. There are no articles available for this product. There are no videos available for this product. There are no articles available for this product. There are no videos available for this product. There are no articles available for this product. There are no videos available for this product. There are no articles available for this product. There are no videos available for this product. There are no articles available for this product.Applications of laptop keys for saleIf you need to be able to do something quickly, it is best to have a computer with keyboard and mouse. For this reason, people are using keyboards and mice as a way to access their computer. People can also use them to type in an email or text message. But there are many problems with using a keyboard and mouse in the office. They can also be dangerous if you don't use them properly. It is best to have a computer with keyboard and mouse.I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well. I can do it myself, but not well.I am very pleased to say that I have just bought a new laptop. The machine is a notebook which is quite powerful and it is an Acer Aspire 5 2 in 1. It is the first time that I have bought a new laptop. I have been using it for several years and it is still in good condition. The computer is really easy to use and the user interface is very clean. The software that I use on the computer is Windows 7 Professional and it is very easy to use. I can't recommend this computer enough. It is an amazing machine and it is worth every penny.The key to success is hard work. The key to success is not luck. The key to success is dedication. The key to success is never giving up. The key to success is staying humble. The key to success is working hard. The key to success is being patient. The key to success is making good decisions. The key to success is having a plan. The key to success is getting more done in less time.
How to Make Ultrasonic Measuring Tool with Display Screen
How to Make Ultrasonic Measuring Tool with Display Screen
Step 1: MaterialsArduino or any Arduino compatible microcontrollerHC - SR04 ultrasonic sensorLCD displaypotentiometerJumperBread boardStep 2: LCD connectionI recently wrote a complete generalized instructionable for this, so you can see the following: https://www.instructables.com/id/Temp-1/Or, read on, and I'll still cover everything in detail here:1aConnect the brown wire (pin 16) to the GND pin of ArduinoConnect the red wire (pin 15) to the 3.3V VCC pin of ArduinoConnect orange, yellow, green and blue (pins 14-11) to pins 2 to 5 on ArduinotwoConnect the white wire (pin 1 on the LCD) to the common ground (pin 16)Connect the gray wire (pin 2 on the LCD) to the universal VCC source (pin 15)Connect the purple wire to the signal pin of the potentiometer (pin 2 on the potentiometer)threeConnect purple wire (pin 1 on potentiometer) to common ground (pin 16)Connect the grey wire (pin on pin) to the universal VCC source (pin 15) on the potentiometerfourConnect the yellow lead (pin 4 on LCD) to pin 12 on ArduinoConnect the black wire (pin 5 on the LCD) to a common ground (pin 1 on the potentiometer or pin 16 on the LCD)Connect the green lead (pin 6 on the LCD) to pin 11 on the ArduinoStep 3: ultrasonic connection5aConnect the red wire from the VCC pin (pin 1) of the ultrasonic sensor to any common VCC source (such as pin 3 of the potentiometer or pin 2 of the LCD)Connect the black wire from the GND pin (pin 4) of the ultrasonic sensor to any common ground (e.g. pin 16 of the LCD or pin 1 of the potentiometer)5bConnect the blue wire from the trigger pin (send) (pin 2) of the ultrasonic sensor to pin 9 of ArduinoConnect the echo (receive) pin (pin 3) of the ultrasonic sensor to pin 10 on the ArduinoStep 4: Code#includeconst int echoPin = 10;long duration;distanceCm= duration*0.034/2;distanceInch = duration*0.0133/2; lcd.setCursor00; // Sets the location at which subsequent text written to the LCD will be displayedlcd.printdistanceCm; // Prints the distance value from the sensorStep 5: complete!
What Is the Best Battery to Mains Converter for You? - Battery to Mains Converter Reviews
What Is the Best Battery to Mains Converter for You? - Battery to Mains Converter Reviews
What are the important factors to consider before purchasing battery to mains converter?If you need to have an electrical device that will power your home or office, then you need to know how to use it. You need to know how to keep it running smoothly. You need to know how to charge it up and keep it running well. You need to know how to check that it is working well and make sure that it is safe to use. You need to know how to test it before you use it. You need to know how to check that it is working well and make sure that it is safe to use.Battery to mains converter is an electrical device that converts electrical energy into mechanical energy.There are so many types of batteries that we have to buy different types of batteries for different purposes. If you want to be able to use your battery for longer then you need to be sure that you are using the right type of battery. When you use a battery that is too heavy then it will fail and that is why you need to check that you are using the right type of battery. There are so many types of batteries that we have to use and when you use a battery that is too heavy then it will fail and that is why you need to check that you are using the right type of battery.Battery to mains converter is a really cheap way to save money. It is very easy to use and you can buy it from anywhere. The main advantage of using it is that you don't have to spend much money on buying it. If you need to buy it, it is very easy to find it. You just need to make sure that you buy it from a good store.Size of battery to mains converterBattery to mains converter is too small to run large computers. You need to be careful about how you use it. If you are using it to run a computer, then you need to use it wisely. It is important to know how to use it safely.The size of battery to mains converter is large. You need to use a bigger battery for your power bank or an external power source for your mobile phone. The larger the battery, the better your mobile phone will perform. Also, if you are using a smartphone with high capacity, it is better to use a larger battery than a smaller battery.This is a very basic concept, but it will make your life easier. You will be able to put together a lot of simple circuits that will save you from buying new batteries every time you want to use your device. If you need to know how to do this, go to www.batteryto-power.com and read through the instructions.Battery to mains converter is not suitable for people who need to use it in their car. They can also use it in their home or office and will save money on your electric bill. This is because they are cheaper than using a larger battery and using a larger size charger. You can also use the smaller size charger if you have an old car that needs to be recycled.This size of battery to mains converter is too small to power all your devices in your home. You need to have a bigger battery to power your devices in your home. It is not easy to make a big size of battery to mains converter because it is expensive. If you are looking for a cheap way to power your devices in your home, then this size of battery to mains converter is the best choice for you. You can use this size of battery to mains converter to make sure that your devices will work properly.How to install battery to mains converterBattery to mains converter is an electrical device that uses batteries to supply electricity to a computer or other device. It can also be used to charge your mobile phone or any other device that requires electricity. The main function of a battery to mains converter is to supply electricity to a device that uses batteries to supply electricity to a computer or other device. A battery to mains converter is an electrical device that uses batteries to supply electricity to a computer or other device. It can also be used to charge your mobile phone or any other device that requires electricity.In order to fix a problem with your current setup, you need to change your system's output. For example, if you have a series power supply that has been programmed to produce 9 volts, then you need to change the output to 12 volts. If you have a different input voltage, you need to change the output to 5 volts. You can also use the input and output of your system to create a low-voltage or high-voltage connection that will provide a better connection between your system and the device that it is connected to.If you need to fix a problem with your system, then you need to check if you have the right person in your life. When you need to fix a problem with your system, then you need to check if you have the right person in your life. When you need to fix a problem with your system, then you need to check if you have the right person in your life. When you need to fix a problem with your system, then you need to check if you have the right person in your life.Battery to mains converter is a means of converting electricity into electrical energy. It is used to produce light, such as in the night time. The electricity is stored in the battery and when the need for electricity is greater, the battery produces electricity. When the need for electricity is less, the battery produces electricity.
A Look Behind the Advantages of a Apple Laptop Keyboard Price
A Look Behind the Advantages of a Apple Laptop Keyboard Price
Introduction to apple laptop keyboard priceI'm really looking forward to buying a new laptop. It's hard to buy a new laptop because there are so many different models. There are some great laptops that I have, but they cost a lot of money. The only way to save money is to get a good laptop that you can use for a long time. So it's important to know how to choose a good laptop for a long time. You can also learn how to use a laptop by reading through this article.Apple laptops are becoming more and more popular. A good way to choose a laptop is to go through reviews of different laptops, which will give you a good idea of what you can expect from a laptop. For example, if you are looking for a good laptop that will be compatible with Windows 10, you should go through the Windows 10 compatibility list and see what other laptops are compatible with it. You can also use the software tools that are available to help you determine what kind of laptop you need.Apple laptops are so cheap that it is hard to find one that will work for you. The prices of Apple laptops are quite expensive and if you need to buy a new laptop then you need to make sure that you have enough money to pay for it. There are some things that you can do to help you save money on your new laptop. It is best to check out the reviews of other people who have bought the same laptop and compare them with your own experience. This will make it easier for you to know what to look for in a laptop and how to choose the best one for you.Apple laptops are more affordable than most people think. A good laptop is one that can be had for a price that will allow you to use it for years to come. If you need to purchase a new laptop then you should be aware of the various different options that are available to you. You should also make sure that you get the best deal possible. There are many different companies that offer laptops at very cheap prices. The only way to ensure that you are getting the best deal possible is to check out their websites.First impression and using experience of apple laptop keyboard priceApple laptops are very cheap, but if you need to use it for work, you should be careful. People with good computers can get better results from laptops that have higher processor and RAM. But if you need to use it for work, you should be careful. People with good computers can get better results from laptops that have higher processor and RAM. But if you need to use it for work, you should be careful. People with good computers can get better results from laptops that have higher processor and RAM. But if you need to use it for work, you should be careful.I don't know how to write a good first impression, but what do you think? what is the most important thing to remember when you are creating a good first impression? some people have said that it is hard to create a good first impression, but what do you think? what is the most important thing to remember when you are creating a good first impression? some people have said that it is hard to create a good first impression, but what do you think? what is the most important thing to remember when you are creating a good first impression?Apple laptops are made to be simple to use and comfortable to use. And they are easy to learn. Apple laptops are designed to be as light as possible. They are small enough to fit in your pocket. And they are very flexible. So you can do anything you want with them. They are so light that you can move around without feeling any trouble. And they are so flexible that you can move around without feeling any trouble. So you can do anything you want with them.You need to know that you are going to be able to create an initial impression of your customers. The more people that you know about the company, the better your company will be. They will also know that you have their business in mind. When you use their feedback, they will feel that you are doing something for them. And when they see that you are working on their behalf, they will feel that you are working for them.Pros and cons of apple laptop keyboard priceApple laptops are great computers that will make your life easier. I am going to give you a short list of some of the main advantages of using an apple laptop keyboard: They are small and light weight, they are easy to use and operate, they are very fast and reliable, they are flexible and can be used in many different applications, they are easy to take out of your pocket and store in your bag, they are cheap and affordable, they are environmentally friendly and you can get them at very cheap prices. The only disadvantage of using an apple laptop keyboard is that they are quite bulky and expensive.It is hard to make an accurate estimate of the popularity of each type of keyboard. It is also hard to make an accurate estimate of the market share of each type of keyboard. The more expensive the keyboard, the more it will be difficult to find good quality keyboards in the market. The more expensive the keyboard, the more it will be difficult to find good quality keyboards in the market. In order to help people make an accurate estimate of the market share of each type of keyboard, we have compiled a list of some of the most popular types of keyboards available in the market.Apple laptops are affordable and easy to use. They also have some of the best features in the world. A good laptop is not just a tool to make work easier. It is a machine that allows you to use your brain, work more efficiently and be more productive. If you want to be a better writer, learn how to write better, or improve your creativity, then a good laptop is a must have.The key to winning at business is having a positive attitude. I always have been able to come up with ideas that work for me. There are so many things that can go wrong in business. People sometimes think that they can do anything and it will work out well. It is not true. The only thing that will work is if you are willing to put in the work. You have to put in the work to make things work.Overall evaluation of apple laptop keyboard priceThere are many things that people have in mind when they think of buying a laptop.If you are interested in learning more about the keypad, it is important to understand that there are two main types of keyfob: USB keyfob and Wi-Fi keyfob. A USB keyfob is a small electronic device that plugs into a computer or smartphone. It has an electrical connection to the computer or smartphone and allows you to use the computer or smartphone to perform various functions. A Wi-Fi keyfob is a small electronic device that connects to a mobile phone or other mobile device and allows you to use the mobile phone to perform various functions.Apple laptops are very cheap and good for people who don't have much money to spend on them. I know that people who are really into computer games can be very happy with their Apple laptops, but it is also possible that they might not be as happy with their computers as they should be. It is possible that people who are very serious about computer games might not be as happy with their computers as they should be. People who are serious about computer games might not be as happy with their computers as they should be. Apple laptops are very cheap and good for people who don't have much money to spend on them.Apple laptops are always looking for new things to do. They want to try out new ideas and learn new things. The good thing about these computers is that they can be very fun to use. You can learn a lot about how to use them and have fun doing it. It is easy to use and will make you want to use them more.The overall evaluation of apple laptop keyboard price is very good. I really like the whole thing. It is really easy to use and I can't say that it is easy to get lost in the simplicity of the software. It is very simple to use and it is very easy to get lost in the simplicity of the software. It is very easy to use and it is very easy to get lost in the simplicity of the software. It is very easy to use and it is very easy to get lost in the simplicity of the software.
How Can the Heat Dissipation of LED Display Screen Be Improved
How Can the Heat Dissipation of LED Display Screen Be Improved
In practical application, improving the heat dissipation of LED display screen can not only effectively improve the efficiency of heat dissipation of LED display screen, but also save power, which is more conducive to improving the service life of LED display screen.1. It is a common method to use a long-life and high-efficiency fan to strengthen heat dissipation inside the lamp shell. This method has low cost and good effect.2. Aluminum cooling fins are the most common way of heat dissipation. Aluminum cooling fins are used as part of the shell to increase the heat dissipation area.3. Aerodynamics, using the shape of the lamp shell to produce convective air, which is the lowest cost method to strengthen heat dissipation.4. Surface radiation heat dissipation treatment: the surface of the lamp shell is treated with radiation heat dissipation. The simpler thing is to apply radiation heat dissipation paint, which can bring the heat away from the surface of the lamp shell by radiation.5. Integration of heat conduction and heat dissipation -- the application of high heat conduction ceramics. The purpose of heat dissipation of lamp shell is to reduce the working temperature of LED HD display chip. Because the expansion coefficient of LED chip is very different from that of our common metal heat conduction and heat dissipation materials, the LED chip cannot be directly welded to avoid high and low temperature thermal stress damaging the chip of LED display.6. The heat conduction tube is used for heat dissipation, and the heat is guided from the LED display chip to the shell heat dissipation fin by using the heat conduction tube technology.7. The thermal conductive plastic shell is filled with thermal conductive materials during injection molding of the plastic shell, so as to increase the thermal conductivity and heat dissipation capacity of the plastic shell.It can be seen that the maturity and progress of LED display heat dissipation technology will be conducive to its concept of saving and environmental protection. LED electronic display manufacturers have a variety of methods to improve the heat dissipation of LED display in the production of LED display. There will be different considerations according to the power and place of use.
The Solution of DC / DC Converter with Integrated Power Supply Magnetic Components Is Discussed
The Solution of DC / DC Converter with Integrated Power Supply Magnetic Components Is Discussed
Many communication equipment architecture standards have fixed base size and power supply. Maintaining a high-efficiency point of load (POL) power supply solution with reduced size helps to improve the card density, save space and achieve the effect of product differentiation. Designers must quickly solve technical problems in the development stage. Simple power solutions can reduce the burden and enable engineers to focus on the development of core competitiveness. The single package DC / DC converter of the integrated magnetic kit can solve many problems. This paper will discuss the advantages and disadvantages of integrated power solutions compared with discrete solutions, and briefly explain the effects of external components, heat dissipation, solution size, noise generation and circuit board adhesion.Integrated power solutionWith the progress of magnetic component design and manufacturing technology, the inductor with smaller size and higher current is placed on the same substrate as the integrated circuit of DC / DC converter. Integrated power solution (IPS) adopts the inductance suitable for DC / DC converter, the package is welded, and the IC, inductance and passive components are attached to the customized metal lead frame. Epoxide is cast on the whole package to completely cover the components, and then a large number of automatic testing equipment (ATE) check the fully encapsulated IPS.Figure 1 shows the back of the Texas Instruments 4.5V to 14.5V input 6A integrated power solution tps84620. The complete load point power supply design can be directly loaded on the circuit board to replace the traditional open power pol DC / DC module. Many semiconductor manufacturers currently use packaging, ate, lead frame and DC / DC converter design expertise to develop pol IPS to power high-performance processors suitable for DSP, FPGA, ASIC and wireless infrastructure. IPS has the same appearance as the integrated circuit and is loaded on the circuit board in the same way.Benefits of integrated power solutionsIntegrated power solutions are easy to use and require fewer external components than discrete solutions. There is no need for small high current inductors matched with DC / DC converters. When selecting the inductance of the power solution, the limits of input voltage, output voltage, switching frequency and output current are determined. Most integrated power solutions require only input / output capacitors and voltage setting resistors, which are listed in the data sheet according to the required input voltage, output voltage, transient efficiency and ripple requirements. After the compensation elements are integrated into the package, the stability demand of the compensation circuit under different temperatures and various load conditions decreases. There is no need to design or load the compensation circuit on the circuit board, and the design time is shortened.The integrated power solution uses a thin QFN package to achieve extremely high power density. Developing discrete solutions of similar size requires a lot of expertise, and digital designers do not need power management expertise to use the size and efficiency designed by senior power designers.balanceAs shown in equation 1, the higher the switching frequency, the smaller the magnetic element. When the switching frequency (FS) increases, the inductance (L) value will decrease. Although fast frequency switching helps to encapsulate small inductors in DC / DC converters, it also limits the achievable load cycle (d), which is the ratio of the output voltage divided by the input voltage.Take 1.2V driven low-voltage processor as an example, 5V or 12V input is the input voltage that can be considered. The integrated power supply solution can operate at a higher input voltage, but due to the limitation of the shortest on time of the DC / DC converter, it is limited to some output voltages. For the input voltage above 28V, the output voltage of 3.3V or 5V is more practical, and the switching frequency must be fast enough to meet the needs of a small amount of inductance. In the data sheet, the IPS shall specify the minimum on time or the minimum output voltage that can be achieved by the specified input voltage.When small solution area or height is not a key factor, the inductance inside the power solution may reach a higher DC impedance than the inductance selected in the discrete design. If a small solution size is not required, designers can design discrete inductors with very low DC impedance, which helps to achieve efficiency goals, depending on application requirements and designer skills.costWhen browsing on the Internet, the retail unit price per thousand of integrated power solutions at first glance seems to be higher than that of discrete DC / DC converters and inductors. However, other costs such as manpower, external component inventory, manufacturing and PCB loading that are not visible to end customers are absorbed by integrated power solution manufacturers. The price of power solutions has the opportunity to be more competitive than discrete solutions, depending on the output of terminal equipment and the time to market.
Current Situation and Optimization of FPGA Heterogeneous Computing
Current Situation and Optimization of FPGA Heterogeneous Computing
The general CNN accelerated design based on FPGA can greatly shorten the FPGA development cycle and support the rapid iteration of service depth learning algorithm; It provides computing performance comparable to GPU, but has the delay advantage of orders of magnitude compared with GPU, and builds the strongest real-time AI service capability for business.WHEN Current situation of deep learning heterogeneous computingWith the rapid growth of Internet users and the rapid expansion of data volume, the demand for computing in data centers is also rising rapidly. At the same time, with the rise of computing intensive fields such as artificial intelligence, high-performance data analysis and financial analysis, the demand for computing power has far exceeded the capacity of traditional CPU processors.Heterogeneous computing is considered to be the key technology to solve this computing gap at this stage. At present, "CPU GPU" and "CPU FPGA" are the heterogeneous computing platforms most concerned by the industry. They have the advantages of higher efficiency and lower latency than traditional CPU parallel computing. In the face of such a huge market, a large number of enterprises in the science and technology industry have invested a lot of funds and manpower, the development standards of heterogeneous programming are gradually maturing, and the mainstream cloud service providers are actively layout.The industry can see that giant companies such as Microsoft have deployed a large number of FPGAs to accelerate AI information. What are the advantages of FPGAs over other devices?Flexibility: programmability naturally adapts to the rapidly evolving ML algorithmDNN, CNN, LSTM, MLP, reinforcement learning, decision tree, etcArbitrary precision dynamic supportModel compression, sparse network, faster and better networkPerformance: build real-time AI service capabilityImproved low latency prediction capability compared to GPU / CPUImproved single watt performance compared to GPU / CPUScaleHigh speed interconnection IO between boardsIntel CPU FPGA ArchitectureAt the same time, the short board of FPGA is also very obvious. FPGA uses HDL hardware description language for development, which has long development cycle and high entry threshold. Taking separate classic models such as Alex net and Google net as examples, it often takes months to customize and accelerate the development of a model. The business side and FPGA acceleration team need to consider both algorithm iteration and adapting FPGA hardware acceleration, which is very painful.On the one hand, we need FPGA to provide low latency and high-performance services that are competitive compared with CPU / GPU. On the other hand, we need the development cycle of FPGA to keep up with the iteration cycle of deep learning algorithm. Based on these two points, we design and develop a general CNN accelerator. Considering the general design of mainstream model operators, the compiler generates instructions to drive model acceleration, which can support model switching in a short time; At the same time, for the emerging deep learning algorithm, the rapid development iteration of relevant operators is carried out on this general basic version, and the accelerated development time of the model is reduced from a few months to one to two weeks.The overall framework of the general CNN accelerator based on FPGA is as follows. The CNN model trained by Caffe / tensorflow / mxnet and other frameworks generates the instructions corresponding to the model through a series of optimization of the compiler; At the same time, the image data and model weight data are preprocessed and compressed according to the optimization rules, and then distributed to the FPGA accelerator through PCIe. The FPGA accelerator works completely according to the instruction set in the instruction buffer. The accelerator executes the instructions in the complete instruction buffer once to complete the calculation and acceleration of a picture depth model. Each functional module is relatively independent and is only responsible for each individual module calculation request. The accelerator is separated from the deep learning model, and the data dependency and pre and post execution relationship of each layer are controlled in the instruction set.In short, the main work of the compiler is to analyze and optimize the model structure, and then generate the instruction set efficiently executed by FPGA. The guiding ideology of compiler optimization is: higher MAC DSP computing efficiency and less memory access requirements.Next, we take the Google net V1 model as an example to make a simple analysis of the accelerator design optimization idea. The network of inception V1 combines 1x1, 3X3, 5x5 conv and 3x3 pooling stack, which increases the width of the network and the adaptability of the network to scale. The following figure shows the basic structure of inception in the model.Data dependency analysisThis part mainly analyzes the pipelined and parallelized computing in the mining model. Pipelining design can improve the utilization of computing units in the accelerator, and parallel computing can use as many computing units as possible at the same time.As for pipelining, the analysis part includes the operation of loading data from DDR to SRAM on FPGA chip and the pipelining calculated by PE. Through this optimization, the memory access time is overlapped; DSP calculates the calculation control process of the whole column to ensure the improvement of DSP utilization.As for parallelism, we need to focus on analyzing the parallel relationship between PE computing array and "post-processing" modules such as activation, pooling and normalization. How to determine the data dependency and prevent conflict is the key to the design here. In inception, it can be seen from its network structure that 1x1 convolution calculation in branch A / B / C and pooling in branch D can be calculated in parallel, and there is no data dependency between them. By optimizing here, the calculation of 3x3 Max pooling layer can be completely overlapped.Model optimizationIn the design, two aspects are mainly considered: finding the optimization of model structure and supporting the fixed-point adjustment of dynamic accuracy.FPGA is a device that supports a large number of parallel computing. Looking for higher dimensional parallelism from the model structure is of great significance for computing efficiency and reducing memory access. In inception V1, we can see that the input data of 1x1 convolution layer in the first layer of branch a branch B branch C is completely consistent, and the strip and pad of convolution layer are consistent. Can we align and overlay on the output feature map dimension? After superposition, the memory access demand for input data is reduced to 1 / 3 of the original.On the other hand, in order to give full play to the acceleration characteristics of FPGA hardware, the influence process of the model needs to carry out fixed-point operation on the model. In FPGA, the performance of int8 can be twice that of int16. However, in order to enable customers in the company and on Tencent cloud to deploy their trained floating-point model without perception, and do not need retrain int8 model to control accuracy loss, we adopt a customized int16 scheme that supports dynamic accuracy adjustment. Through this method, the user trained model can be deployed directly through the compiler without any loss of accuracy.Memory architecture designBandwidth is always one of the bottlenecks restricting the performance of computer architecture. At the same time, memory access directly affects the power consumption efficiency of accelerator devices.In order to minimize DDR memory access during model calculation, we designed the following memory architecture:Input buffer and output buffer ping pong are designed to maximize pipelining and parallelismSupport the inner copy operation between the input buffer and the output buffer itselfCross copy operation between input buffer and output bufferThrough this architecture, for most current mainstream models, the accelerator can hold all the intermediate data on the FPGA chip. In addition to the loading of model weight, the intermediate does not need to consume any additional memory operation. For the model that cannot completely store the middle tier feature map on the slice, we introduce the concept of slice slice slice in the channel dimension and part slice in the feature map dimension. Through the compiler, the primary convolution or poolingnorm operation is reasonably split, and the DDR memory access operation is pipelined with FPGA accelerated calculation. On the premise of giving priority to ensuring the DSP computing efficiency, the memory access demand of DDR is minimized.Calculation unit designThe core of the general CNN accelerator based on FPGA is its computing unit. The current version of the accelerator is designed based on Xilinx ku115 chip. The PE computing unit is composed of 4096 MAC DSP cores working at 500MHz, with a theoretical peak computing capacity of 4tflops. Its basic organizational framework is shown in the figure below.Ku115 chip is stacked by two die pairs, and two groups of processing units PE are placed in parallel in the accelerator. Each PE is composed of four groups of Xbar composed of 32x16 = 512 MAC computing DSP cores. The key of the design is to improve the data multiplexing in the design, reduce the bandwidth, realize the multiplexing of model weight and each layer feature map, and improve the computing efficiency.Application scenarios and performance comparisonAt present, the mainstream of deep learning uses GPU for the training process of deep learning. When deploying online inference, it is necessary to comprehensively consider the characteristics of real-time, low cost and low power consumption and select the acceleration platform. Classified by deep learning landing scenarios, advertising recommendation, speech recognition, real-time monitoring of picture / video content belong to real-time AI services and real-time low-power scenarios of terminals such as intelligent transportation, intelligent speakers and driverless. Compared with GPU, FPGA can provide strong real-time and high-performance support for business.What is the platform performance, development cycle and ease of use for users?Acceleration performanceTaking the actual Google V1 model as an example, the CPU test environment: two 6-core CPUs (e5-2620v3) with 64g memory.When the CPU of the whole machine is full, the performance of a single ku115 based accelerator is 16 times higher than that of the CPU, the detection delay of a single picture is reduced from 250ms to 4ms, and the TCO cost is reduced by 90%.Meanwhile, the prediction performance of FPGA is slightly better than that of NVIDIA GPU P4, but the delay is optimized by an order of magnitude.development cycle The general CNN FPGA acceleration architecture can support the deep learning model in the rapid iteration and continuous evolution of business, including classic models such as Google net / VGg / RESNET / shufflenet / mobilenet and new model variants.For classical models and algorithm variants based on standard layer self-developed, the existing acceleration architecture can already support, and the corresponding instruction set of the model can be implemented through the compiler within one day to realize deployment online.For self-developed special models, such as asymmetric convolution operator and asymmetric pooling operation, iterative development of relevant operators needs to be carried out on this platform according to the actual model structure, and the development cycle can be shortened to support within one to two weeks.Ease of useFPGA CNN accelerator encapsulates the underlying acceleration process and provides easy-to-use SDK to the business parties of the acceleration platform. The business party can complete the acceleration operation by calling simple API functions, and there is almost no change to the business logic.epilogueThe general CNN accelerated design based on FPGA can greatly shorten the FPGA development cycle and support the rapid iteration of service depth learning algorithm; It provides computing performance comparable to GPU, but has a delay advantage of orders of magnitude compared with GPU. The general RNN / DNN platform is under intense research and development, and the FPGA accelerator builds the strongest real-time AI service capability for the business.In the cloud, at the beginning of 2017, we launched the first domestic FPGA public cloud server in Tencent cloud. We will gradually introduce the basic AI acceleration capability to the public cloud.The battlefield of AI heterogeneous acceleration is great and wonderful. Providing the best solution for the company's internal and cloud business is the direction of the continuous efforts of the FPGAs team.If the online model needs to be changed, just call the model initialization function and initialize the corresponding model instruction set to FPGA. The acceleration service can be switched in a few seconds.About the author:Derickwang (Wang Yuwei), graduated from Huazhong University of science and technology in 2014, with a master's degree. His main research and practice direction is FPGA heterogeneous computing in data center, and his project
A Quick Guide to the How to Open Laptop Keyboard for Industries
A Quick Guide to the How to Open Laptop Keyboard for Industries
About how to open laptop keyboardJust about everybody has an internet connection at home. You can do all sorts of things online, including play games, use email, or send emails. It is very easy to access information and information that you need from anywhere in the world. There are also many apps that you can use to make your life easier. If you need to do something online, then there are plenty of websites that you can use to get information and information that you need.While we use different operating systems and browsers, we all use the same basic functions. For example, when you type a name in the search bar, the result is displayed in the search box. In order to get a better understanding of how to open laptop keyboard, we should be able to read through some examples. For example, if you want to find a list of websites that provide free wireless Internet access, you can use the internet browser as well as a mobile phone. When you are trying to find a certain web page, you can just press the home button and wait for the page to load.When you type something, it will take longer than usual to get a reaction. For example, when you type the word 'basketball' it takes longer than usual to get a response. But if you press the arrow keys and then hit enter, it will take longer than usual to get a response. It is because of this that people tend to use the keyboard more slowly than usual. So if you are in a hurry to type something, you can also try to press the arrows keys.Most of the time it is necessary to get rid of your computer and install a new one. If you are looking for a way to change the desktop and make it look new, you can use this method. It is an easy way to change the desktop. The key is to have a professional technician that will fix your computer quickly and accurately.What are the benefits of using how to open laptop keyboard?In order to be able to use your laptop, you need to know how to open it. You need to know how to use your laptop. If you don't know how to use your laptop, you won't be able to use it. So if you don't know how to use your laptop, you won't be able to use it. That's why you need to learn how to use your laptop. If you don't know how to use your laptop, you won't be able to use it. So if you don't know how to use your laptop, you won't be able to use it.When you use the laptop keyboard, you can type quickly and easily. It is much easier to write, think and read. You can also be more productive when using the laptop keyboard. With how to open laptop keyboard, you can type fast and easily. It is much easier to write, think and read. You can also be more productive when using the laptop keyboard. With how to open laptop keyboard, you can type fast and easily. It is much easier to write, think and read. You can also be more productive when using the laptop keyboard.It is important to know that some people think that there are no problems with using how to open laptop keyboard. They do not know that it is possible to open laptop keyboard with their own hands. It is necessary to learn how to open laptop keyboard by yourself.I would recommend that you read through this article first. This article is a quick guide to some of the most important features of how to open laptop keyboard. There are many good things about using how to open laptop keyboard. It is very easy to use and provides many options for changing the font, size, and color of the text. You can also add images to your text.How does how to open laptop keyboard work?Some of the most common ways to open laptop keyboard are: input key, touch key, and power key. There are also some alternatives to these methods. When you press the input key, the computer will begin to interpret the keys as they will be used in the program you are running. In most cases, you will see that the computer will tell you what keys to press.If you need to use your laptop as a portable computer, then you will need to know how to open your laptop keyboard. You can use the key combination of the keyboard to access the screen. If you are using a notebook or desktop computer, then you can use the key combination of the keyboard to access the screen. In both cases, you will need to have a USB port on your computer. So, in order to use your laptop keyboard, you will need to have a USB port on your computer.As soon as you get your laptop into your hands, the keypad is already open. You just have to press the home button and you're done. This keypad has several buttons that can be used to type in any text you want. For example, you can use the Shift and Control keys to move around in the text. And you can also use the W and C keys to turn on the computer.Just one example of the way that using a laptop keyboard works is that you can have it turn off when you press the mouse button. When you do that, the computer will not use the mouse and instead it will use the keys on the keyboard. If you want to change the way that the computer uses the keyboard, you can set the way that the computer uses the keyboard to be as follows: Press the [Ctrl] key and then press the letter for the function you want to change. You can also press the space bar to get back to the normal way that the computer uses the keyboard.What is the cost for how to open laptop keyboard?Laptop keyboards are expensive. When I asked a shop that sells laptops, they told me that it costs about 500 yen. That's about 1,000 Japanese yen. The prices of laptops vary greatly. I'm sure that there are cheaper laptops out there, but if you want to buy a laptop, you have to pay the most. It's just not cheap.The cost for how to open laptop keyboard is quite expensive. If you have an idea of how to open laptop keyboard, then it is not hard to find out how to open laptop keyboard. The price of how to open laptop keyboard depends on many factors, such as the type of laptop, the size of the laptop, the manufacturer of the laptop, the number of operating systems and so on. So it is important to know how to open laptop keyboard before you decide to buy it.When you have an emergency that will cost you money, the first option is to shut down your computer. When you are at work, it is possible to have a computer with lots of users. But if you need to use your computer for a long time, it is better to buy a good laptop. In order to be able to use your laptop for a long time, you need to buy a good laptop. The price of a good laptop depends on many factors, but there are some important factors that affect the price of a good laptop.It is very important to understand that there are several methods of opening laptop keyboard. Some of them are fast and some are slow. If you want to know how to open laptop keyboard, then it is very important to understand that there are several methods of opening laptop keyboard. Some of them are fast and some are slow. If you want to know how to open laptop keyboard, then it is very important to understand that there are several methods of opening laptop keyboard.
The 5 Best Reasons Why You Should Use a Add Light to Laptop Keyboard
The 5 Best Reasons Why You Should Use a Add Light to Laptop Keyboard
What to look for in add light to laptop keyboardMost laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic. Most laptops have an optic.The key to using add light to laptop keyboard is having good lighting. Having good lighting will help you make better decisions about how to use your laptop. The good lighting will help you focus on what you are doing and not be distracted by anything else. It will also help you get more done in less time.Laptop is important in today's world. The most important thing in the world is the laptop. The world is getting more advanced and we need to use it more and more. We are moving from big town to big city and that is why we need to use laptops more and more. And Laptop is important in today's world. We need to use laptops more and more.Just use your imagination and use it. It is the most important part of a good design. There are so many different designs out there that it is impossible to say what you need. You need to know what you need and then make sure that you can get it. If you can't, then you will end up spending a lot of time looking for the perfect design.I have an old laptop with a high powerlight and need to be able to adjust the brightness of the screen. I use an upgradeable battery that will run off 3 batteries per day. The problem is that I don't know how to set the brightness of the screen. The last update I made was about 10 years ago and it has still not worked well. The only way to fix it is to buy a new battery and make sure that it has enough power to keep the screen lit for at least 2 hours. This would be easy to do by changing the batteries every couple of months.Shopping tips for add light to laptop keyboardWhile shopping for a laptop, many people go to the computer console and find that there are no controls for anything. For some people, this is not a problem. But for others, it is a problem. It is very important to understand that if you have no control over the computer, you cannot use it as a device for doing anything. A computer is not a toy. If you use it as a toy, you can't use it as a device for doing anything.There are lots of places that will be able to provide you with many different things that you can use to enhance your laptop. If you want to get some extra light in your laptop, then there are many places that will be able to provide you with many different things that you can use to enhance your laptop. There are lots of places that will be able to provide you with many different things that you can use to enhance your laptop. If you want to get some extra light in your laptop, then there are many places that will be able to provide you with many different things that you can use to enhance your laptop.People have bought laptops with keyboards that are difficult to use. You should be able to get used to using your laptop more easily if you use it with a good pair of mouse and keyboard. It is also important to note that people who have problems with their keyboards tend to use them less than those who don't. They may also use them more slowly.It is important to use a good mouse. The quality of the mouse will determine the performance of the computer. The right mouse will allow you to focus on the task at hand. It will be easier to type and write on the computer. You will also be able to work more efficiently. Make sure that the mouse is small and easy to handle. A good mouse will be able to give you the best results.add light to laptop keyboard for different budgetsIf you are using a Macbook Air, use this power source to charge your laptop. If you are using a Macbook Pro, use this power source to charge your laptop. You can use the USB port on your Macbook Air to charge your laptop. When you are finished using your laptop, plug it into the wall outlet and leave it there for 5 minutes. After that, plug it into the wall outlet and leave it there for 5 minutes. After that, plug it into the wall outlet and leave it there for 5 minutes.The amount of light emitted from a computer is an important parameter to determine the quality of light that can be used in a professional studio. To achieve this, it is necessary to know the level of illumination that will be generated by the screen and how much it will cost to generate that light. With this information, it is possible to design a software solution that will produce light for different users and create a free space for them to work.There are several things that make laptops more comfortable than desktops. There are a number of factors that affect the user experience of laptops.The computer mouse is one of the most important accessories in a person's life. When you use it, you can easily change the appearance of your computer and your work. The main advantage of using a mouse is that it allows you to control the appearance of your computer more easily. It also helps you to improve the typing speed and write better text.Add light to laptop keyboard for different budgets Consortium of Universities and Colleges of the South China Sea (CUSOC) is committed to support all its students in order to create a more sustainable society. As the report suggests, adding light to laptops will be an integral part of the curriculum and will help students work more efficiently. The technology is also known to improve their productivity and reduce the need for computers in their lives. In fact, some have even said that adding light to laptops will make people more productive.
Circuit Design of Control Card Based on an Ultra Long LED Display Screen
Circuit Design of Control Card Based on an Ultra Long LED Display Screen
In the application of LED display screen, ultra long strip LED screen is a very wide form, which is characterized by "extremely long" length and narrow width. At present, there is no clear definition of ultra long LED display screen. It is more appropriate to define the number of points in its horizontal direction as 2048.Taking the ultra long strip LED display screen composed of 1 / 4 scanning P10 unit board (point spacing 10 mm) as an example, when the number of points in the horizontal direction is 2048, its physical size in the horizontal direction is 20.48 M. the number of points in the width (vertical direction) of LED screen is generally 16, 24 and 32 points, no more than 64 points at most. In application, it is mainly Chinese characters that can display a line of various fonts. In order to ensure the refresh rate, in the control of ultra long LED display, it is required to send more data within the specified time. It is difficult for ordinary LED display control card to meet the control requirements.Based on the analysis of various existing strip LED display unit board circuits, an LED display control system based on multi port serial flash memory is proposed in this paper. The SPI interface of single chip microcomputer is used to generate a controllable clock, and the display data in multi port serial flash memory is directly output to ultra long strip LED display screen in "DMA" mode.1. Connection mode of internal serial shift register of common unit boardFigure 1 shows three connection modes of internal serial shift registers of common unit boards. Figure 1 (a) shows the connection relationship between the unit board 74HC595 and the LED light emitting tube dot matrix and the simplified representation circuit. The serial shift register used inside the LED display unit board is generally 74HC595, mbi5026 or mbi5026 compatible chip, and mbi5026 can be regarded as composed of two 74HC595 cascades, which is a constant current source driving mode, which is more suitable for LED driving.Figure 1 (b), (c) and (d) show the connection modes of P10, p16, f3.75 or f5.0 unit boards respectively.Fig. 1 connection mode of internal serial shift register of three common unit boards2 problems and solutions of ultra long LED displayAt present, a large number of door screen (strip LED display) in the market is the most widely used form of LED display. Technically, the number of points in the horizontal direction of the door head screen ranges from 256 points to thousands of points, and the height generally does not exceed 64 points. With the improvement of market demand and display accuracy, the demand for ultra long LED display with thousands of points is increasing. Ordinary LED display control card is difficult to meet the requirements of refresh rate. Take f3.75 LED display with 4096 pixels in length as an example, set the refresh rate as 60 Hz, and its SCK clock cycle is at least 106 / 60 / 16 / 4096 = 0.254 s = 254 ns.There are two methods to solve the data output of ultra long LED display screen: one is to select high-performance embedded processor and FPGA chip, which has high cost of control card; The second is to skillfully apply the special functional components on the single chip microcomputer and optimize the data organization algorithm, which has a very low cost. The second method is adopted in this paper. The data is pre written into the multi port serial flash memory sst26vf016b through the optimization algorithm. The SPI component of stc12c5616 single chip microcomputer is used to generate a high-speed controllable SCK clock, and the display data in the multi port serial flash memory is directly output to the ultra long strip LED display screen in "DMA" mode, Meet the display requirements of ultra long LED display.The height of ultra long LED display screen generally does not exceed 64 points. If 1 / 16 scanning monochrome LED display screen is controlled, the 4-bit data port of sst26vf016b memory just meets the needs of LED display screen data port width. Figure 2 shows the control sequence of sst26vf016b memory, CS is the chip selection end of sst26vf016b memory, and all operations on the memory shall be carried out when CS is low level; SCK is a clock line. When in idle mode, SCK signal can be in low level state (mode 0) or high level state (mode 3); SiO (3:0) is a 4-bit data port. During data transmission, the upper 4 bits of the byte are transmitted first, and then the lower 4 bits of the byte are transmitted. It can be seen from the control timing of the memory that the control of the memory is sent in the order of command word, 24 bit storage address, virtual byte, data byte 0 to data byte n. The command word of the memory can realize the functions of chip erase, sector erase, single byte read-write, continuous byte read-write and so on, which can fully meet the requirements of ultra long LED display screen for memory capacity and control mode.Fig. 2 control sequence of sst26vf016b memory.Stc12c5616 is a high-speed 1t single chip microcomputer launched by STC company. The clock frequency can reach more than 30 MHz. It integrates a high-speed serial communication interface component (i.e. SPI interface). When the SPI component of stc12c5616 works in the main mode, its SPI clock output frequency (fclk) can reach 1 / 4 times of the crystal oscillator frequency (FOSC), and its clock phase and clock polarity can be flexibly configured to meet the requirements of sst26vf016b memory control and the clock requirements of ultra long LED display screen.3 circuit design of super long LED display control cardThe multi bit data port memory of the serial flash memory sst26vf016b and the SPI component of the stc12c5616 single chip microcomputer can generate a high-speed SCK clock to bypass the display data from the serial flash memory to the LED display screen. The circuit is shown in Figure 3.Fig. 3 circuit diagram of super long LED display control card.When the dynamic refresh rate of the display screen reaches 50 times / s, the display time of one line on the 1 / 16 scanned LED display screen shall be less than 1 / 50 / 16 S, i.e. 1.25 Ms. in the design of the control card, when FOSC = 22 MHz, the serial flash clock frequency fclk = 1 / 4 FOSC = 5.5 MHz, so the time required for 4096 CLK clocks is 4096 1 /5. 5 106) s = 0.744 MS, and the time after sending memory instructions and addresses using SQI protocol is also less than 1.25 Ms. therefore, in Figure 3, the 22 MHz clock is selected for the external clock of single chip microcomputer stc12c5616, which can ensure the display of 4096 ultra long display screen under SQI protocol mode.The external clock of single chip microcomputer stc12c5616 is 22.118 4 MHz, which is convenient for the accurate control of serial port baud rate; Pins P3. 0 and P3. 1 are UART interfaces, and the communication connection between the control card and the PC is realized through the communication interface chip MAX232; Pins p2.0 p2.3 are 4-bit data lines. On the one hand, the data line is connected to the 4-bit data port of memory sst26vf016b, and on the other hand, it is driven by 74hc245 and connected to the data line of LED unit board output interface. Two monochrome LED unit board output interfaces are designed on the control card. The interface J1 uses data lines d0 and D1, and the interface J2 uses data lines D2 and D3; Pin P1.7 is SPI clock output, and the SPI clock output line is connected to the clock input of serial flash memory sst26vf016b and LED unit board at the same time; Pin P1.4 is the chip selection signal of serial flash memory sst26vf016b; Pin p3.5 is the data latch signal of LED unit board; Pin P3. 7 is the enable signal output of LED unit board; Pins P1.0 p1.3 are row selection signal output of LED unit board; J1 and J2 connectors are used to connect the LED unit board of the display screen in the height direction to meet the 64 point height requirements of the door head screen.The circuit design can flexibly realize three different data access modes among single chip microcomputer, serial memory and LED unit board, which are:(1) Normal access between MCU and memory.As can be seen from Figure 3, the connection between the single chip microcomputer stc12c5616 and the serial flash memory sst26vf016b is connected with reference to the data manual, which can realize normal data access. At the same time, the data will also enter the shift register buffer on the LED unit board, but as long as the data latch RCK on the LED unit board does not get a valid signal, The data entering the LED unit board is invalid data that is not displayed.(2) Data communication between MCU and LED unit board.Set the MCU pin P1.4 to the high level, that is, the enable end of the serial flash memory is invalid. At this time, the data port of the memory is in a high resistance state. The data communication between the MCU and the LED unit board will not be affected by the memory data port, and the data of the MCU can be normally output to the LED unit board.(3) Data transfer between memory and LED display.Firstly, the (1) mode is adopted. The single chip microcomputer first outputs the command word, storage address and virtual bytes to the serial memory, then sets all the data ports p2.0 p2.3 of the single chip microcomputer to the high level, reads the display data from the serial memory through the SPI clock, and enters the LED unit board in the "DMA" mode. After reading a line of data, This line of data can be displayed by generating a valid signal on the data latch end RCK on the LED unit board. When using this mode, be sure to set pins p2.0 p2.3 of MCU stc12c5616 to "weak pull-up" mode.4 program design of ultra long LED display screenIn the hardware circuit design of 1 / 16 monochrome LED display screen, 74HC595 is connected in straight through mode. According to the characteristics of the through mode, the monochrome display data is optimized and organized in advance, and the organized display data is stored in the serial flash memory sst26vf016b in advance. As shown in Figure 4, when the single chip microcomputer outputs and displays each line of data, it is repeated in the order of "output data send shift pulse address plus 1". After one line is displayed, RCK latches and displays, and switches the line strobe line through ABCD.Figure 4 1 / 16 scanning monochrome f3.75 or f5.0 unit board (64 32 points) connection mode.Taking the number of horizontal points of LED display screen as 4096 points as an example, the program code for displaying one frame of data is as follows:unsigned char Lnunsigned int Data_LengthLw = 4096;unsigned long Addr;Data_Length = Bv* LwAddr = Begin_Addr Ln* Data_Length;CS = 0;Sendsqi_byte (0x0b); / / send read command// send 3 byte addressSendsqi_byte ((0xff); / / send virtual bytesP2 = P2 |0x0f;Spctl = 0xd0; / / allow SPI interfaceSpdat = 0xff; / / start the first SPI transmission/ / SPI clock transmits 8 pulses at a timeSpstat = 0x80; / / clear receive flagSpdat = 0xff; / / start SPI sendingData_Length -- ;Spstat = 0x80; / / clear receive flagSpctl = 0x90; / / disable SPI interfaceCS = 1; /* disable devicce * /EN = 0;RCK = 1; RCK = 0;EN = 1;In the design of the program, the display screen is only closed during line feed to avoid afterglow, and it is lit in the rest of the time. In the program, BV is the number of 595 groups used in the vertical direction of the data line; LW is the number of pixels in the horizontal direction of the LED display screen; ln is the data line number displayed on the current LED display screen. When displaying data, the data output mode of memory and LED display screen is adopted, and the single chip microcomputer is used First output the "read data" command word "0x0b" to the serial memory, then output the 24 bit address and virtual bytes, and then make the MCU data port output high level, so that the SCK pulse can be output according to the length of the LED display screen. After sending a line of data, prohibit the SPI interface, the RCK latch signal is valid, switch to the next line, and continue to output the display data according to the repeated steps.5 testAfter the test, the display screen is normal without jitter. Use logic
no data
you might like
no data
Contact Us
Leave a message
We welcome custom designs and ideas and is able to cater to the specific requirements. for more information, please visit the website or contact us directly with questions or inquiries.
Contact US

    Bao’an District  Shenzhen City, China

     +86 189 3806 5764

NEWSLETTER SUBSCRIBE
no data
Copyright © 2021 CrowBerry

   

chat online
NEED HELP? WE'RE HERE!