tft lcd serial interface brands

A TFT, or Thin-Film Transistor, utilizes a display that allows for each pixel to be controlled by a transistor and separately address each position. The components of a TFT LCD module are a TFT LCD panel, one or more COG or COB driver ICs, a backlight, and an interface. An interface is a shared boundary across which two separate components of a computer system exchange information. As TFT displays have started being mass produced, production has improved, and the price has become more affordable.

There are now a number of TFT display interface technologies. The best interface to choose relies on particular end-product considerations. The last several years have seen the development of numerous TFT display interfaces, including LVDS (Low-Voltage Differential Signaling), parallel, SPI (Serial Peripheral Interface), and I2C or I2C (also known as I squared C) display, and others.

An SPI or Serial Peripheral Interface enables data exchange between two devices. Compared to parallel ones, it has the benefit of more intuitive and simple wiring. Since there is substantially less contact or crosstalk in the cable, SPI also allows for longer cables. The disadvantage of SPI is that it is slow and only allows for writing to the TFT LCD panel. SPI is typically used in smaller TFT LCD screens because of this. But perhaps your project might require a built-in LCD controller, for which an MCU Parallel interface might be a good fit.

An MCUPI or an MCU Parallel interface is usually pretty simple and usually requires display RAM. There are two common types that are found; the first is 6800, and the other is 8080. 8080 is nRD and nWR, 6800 is RD/nWR and E. A unique sort of parallel interface is the RGB interface. There is no need for display RAM. The MCU directly updates the TFT screen by delivering Red, Green, and Blue sub-pixel data (16/18/24 bits) and timing signals. The RGB interface offers a high-speed connection but requires more data cables and has more complicated controls.

A high-speed serial interface between a host CPU and a display module called MIPI Display Serial Interface allows for the integration of displays to provide high performance, low power, and low electromagnetic interference (EMI) while also lowering the number of pins and retaining vendor compatibility. Designers can use MIPI DSI to provide transmission of stereoscopic content and to enable excellent color rendering for the most demanding picture and video situations.

Low-voltage differential signaling, or LVDS, is a high-speed, long-distance digital interface that transmits serial data (one bit at a time) through two copper wires that are 180 degrees apart from one another. This setup makes the noise easier to identify and filter, which lowers noise emissions. Focus LCDs offers a versatile display that uses this technology, E70RA-HW520-C. The monitor in question is a 7.0" TFT with 1024x600 pixels and a maximum color depth of 16.7M. The inbuilt gate and source driver ICs in this display can be programmed using a typical graphics controller.

HDMI is one that many consumers may already be familiar with. High Definition Media Interface provides a connector and cable definition that supports high-bandwidth video and audio streams. HDMI is an almost direct replacement for analog video standards.

There are then a diverse set of interfaces that can be considered for your display project; whether you decide to go with HDMI, LVDS, MIPI DSI, or the others mentioned, or simply can"t decide, feel free to contact Focus LCDs, where we can address use-case specific questions and provide additional details.

A wide variety of tft display serial interface options are available to you, You can also choose from tft, ips and standard tft display serial interface,

We will organize the kinds of display interfaces we offer, and how they differ. You will get to know what kind of external and internal interfaces we have and what are their main applications.

First, let us start with dividing internal and external interfaces in LCD modules. Internal interface of display means it used inside the device. Those are usually the embedded interfaces that are not visible, and we do not have access to them as the users of the device. External interfaces, on the other hand, are connected to the device using a cable. Once we have defined internal and external interfaces, both of these categories come as universal or image transfer interfaces.

A protocol defines the rules of information exchange, where the interface is the medium. The example here could be the language. When I use my voice to communicate with other people, my voice is an interface. Over this interface my voice is being sent to other people’s ears, and the protocol is the language used. Right now, I am using the English protocol. If you understand the protocol, you understand what I am saying. If I switch to a different language, Polish or some other language that you do not understand, you have the same interface, you will still hear me, but because of a different protocol, you do not understand me anymore. In this article we will talk only about interfaces, how to connect devices to each other. We will not focus on protocols.

Let’s try to get the interfaces right. For internal interfaces, interfaces embedded into the device, we have universal interfaces and image transfer interfaces. Universal display interface can send other data, not only an image. Being universal, they are not perfect for image transfer, because in most of the displays used nowadays, the image transfer is one of the most demanding. The bit rate, the data transfer needed for the image transfer is rather high. Higher that many universal interfaces can offer. If we need to send an image every once in a while, then we don’t need very high bandwidth. If we do not need live video stream, then we can use some of the internal universal interfaces such as SPI, I2C or even slow interfaces as RS232 or UART.

The first universal interface will be SPI (Serial Peripheral Interface). This interface is serial, used for communication between a host, in SPI called a Master, and devices called Slaves. One host can communicate with many slaves. To select the Slave, we use the Chip select or SS line and then we use two data lines, Master output or Master input. And of course we have to define the clock, to synchronize the data, because this is a clock synchronized interface.

It can be fast but is not fast enough for live video. The baud rate can be 1 MBd, but it can also be 10 MBd or even 50 MBd on the SPI or QSPI. QSPI is a Quad SPI, a kind of modification of SPI that is faster. But still this interface is very universal, we can use it to connect memory or some input and outputs internally in our device. In the display universe the SPI is used for simple displays, for small size displays, where we can transfer the image relatively fast, because the resolution is low. The maximum size for SPI display interface would be 3.5 inch, 320 by 240 pixel TFT displays. If we have higher resolution, image transfer will be too slow to use SPI even with a high-speed SPI.

Next, we have the I2C interface. This kind of interface is usually slower than SPI. It uses only two lines, so one is a clock for synchronization, and the other one is the data line. This data line is bidirectional. It means that if in SPI we have two data lines, one outgoing and one incoming, then in an I2C interface we have only one data line.

If, for example, the Master is sending some data, the only thing Slaves can do is to receive it. And then we need to wait a little bit for the Master to finish. We can then respond as Slave to Master. In I2C Slave selection works a little bit different than in SPI, where  we had a Chip Select line (CS line) or SS line to select from. In I2C we first need to send the logical address to the interface that is being written by Slaves. In general, this procedure is slow and universal interface used also to connect the simple memory and some other I2S that we have around our microcontroller on the PCB. It is very useful, but usually not used for image transfer. This interface is very popular in the display world for touchscreens. Most of the embedded touch screens that we use have I2C interface because the touchscreen does not generate many data. We only have coordinates of the finger or few fingers at most, that need to be sent back to the microcontroller, to the device processor. The slow baud rate is good enough for the touchscreen, but not enough for the image.

The next interface, a very old one nowadays, is RS232. This is also a serial, slow interface, which can be used internally in the device or externally. On the picture above we can see the external connectors, but it is still being used internally because it has a variation – UART.

The UART is basically the same as RS232, but it is a fully internal interface. It is pretty slow. We have a TX line and a RX line – a Transmit Line and a Receive Line. We do not have a clock here, we only have a clock to synchronize the device internally, but the clock signal is not sent out. So, we need to synchronize the data that is coming through the lines and to do that we need to set the same baud rate on both sides of the communication line. That means that before we use UART we need to agree first what speed we will use.

That is not a case for SPI or I2C, because we have a clock there that gives the speed to every device. Then each device works according to the clock. In UART we do not have a clock. It is rather not used for image transfer. The UART, or SPI, or I2C can be used for low resolution displays. For high resolution displays we need an Intelligent Display, a display that will generate the image internally and through these slow universal interfaces we only send commands, or we send the image once, the image is being stored into the internal memory of the intelligent display, that we will use later sending the commands. You can find Riverdi’s intelligent display line on our website: https://riverdi.com/product-category/intelligent-displays/.

These Riverdi products are very advanced Intelligent Displays, made with Bridgetek controllers. The controllers use SPI and QSPI for communication. That means your software, your system, your microcontroller can be simple. You can use SPI interface to drive them, and you can still have high resolution image, even as high as 1280 by 800 pixels in 10.1-inch LCD displays. So, please remember that if you want to use a slow universal interface and have a high-resolution image, you need to use an Intelligent Display.

There are also the internal image transfer interfaces. The image transfer interface allows continuous high speed image transfer. Internal transfer is high enough to refresh the display many times per second. This is called the refresh rate of a display. When you go to a display, monitor, or TV set specification, you will see  refresh rate or maximum refresh rate parameter. If it’s 60 Hertz, that means the display image is refreshed 60 times per second. More advanced displays would have higher values, like 100 Hertz. The refresh rate means we need to send full image 60 times or 100 times in each second. To visualize this amount of data, we need to multiply refresh rate by the resolution of the screen. For example, for a 7-inch Riverdi LVDS display with resolution 1024 by 600 it is roughly 600 thousand pixels.

The most common internal image transfer interface in industrial LCD displays nowadays is LVDS – Low Voltage Differential Signal. A crucial feature of this interface is that it is differential. It means that the signal is immune to interference and we can use a twisted pair of wires to transfer the data. We can send data fast and it will not be corrupt by any noise, interference. This kind of data corruption is quite common in other interfaces.

The next, older image transfer interface is called RGB. Name comes from the colors sent parallelly to the display: red, green and blue. LVDS is a serial interface and the RGB is a parallel interface. The main difference is that RGB is not differential, so it is easier to disturb signal with noise and you configure the speed of this interface too high. Parallel interface means that we send every bit in a separate line. In theory this interface could be fast, but because it is not differential, the transfer speed is limited. Moreover, the RGB display interface will work with rather small screen sizes –  usually up to 7-inch or 10-inch.

12 inch screen size is the total maximum for a LCD display with RGB interface, but the resolution will be lower, like 800 by 600. For this display size it is very low resolution. This is the reason why the 7-inch is size above which the LCD displays are being switched from RGB to LVDS interface. Among Riverdi products (if you go to the Riverdi website and to the IPS display tab), there are displays without the controller, and the small displays like 3.5-inch, 4.3-inch and 5-inch are equipped with RGB interface. But when you go to the 7-inch LCD displays tab on Riverdi website, you will find RGB, LVDS and MIPI displays. But when you go to the 10-inch or bigger displays, you will only find the LVDS displays because our 10-inch LCD displays are high resolution 1280 by 800, and it is impossible to build it with the RGB interface.

MIPI – Mobile Industry Processor Interface – is an internally embedded image transfer interface, getting popular these days. This kind of interface is used in mobile applications, tablets or mobile phones, but it is entering as an option in industrial applications. In Riverdi we offer 7-inch MIPI displays, but please be careful with other MIPI displays on the market. Many come from mobile phones or tablet market. Also, the TFT glass availability may not be stable as the mobile market changes really fast, every six months or every year. When you buy a 7-inch Riverdi MIPI interface display you are safe, because it is an industrial display.

This is why we have a limited number of displays with MIPI interface – we want to be sure that what we sale will be available for a long time. Longevity is one of Riverdi’s core values and we do not want to deliver anything that will not be supported for a minimum 3 to 5 years. It is because many of our customers are making industrial, medical or military devices and they need displays to be available long-term.

Next interface is the Vx1. It is similar to LVDS  and MIPI, so it’s low voltage differential signal. Vx1 is a very high-speed interface, usually used in large high-resolution screens, like 55-inch 4K TVs or even larger ones. If you buy this kind of a TV set right now, probably the embedded interface inside will be the Vx1.

Key takeaway: Vx1 is a super-fast interface used for high bandwidth image transfer, with high refresh rate and high-resolution displays, used in 4K screens and above.

The last internal image transfer interface is Embedded DisplayPort (eDP). We call it the new LVDS, because many new industrial displays are equipped with the eDP. If you go through industrial manufacturers of TFT LCD displays, you will notice increasing number of models available with the eDP. eDP is also a native interface in new Intel or AMD based processors.

Key Takeaway: With the embedded DisplayPort as a native display interface you can cut down costs, because you do not need anything extra to connect a display to the processor.

Now, with the processors on the market, we need displays with embedded DisplayPort. Many laptops or monitors already use embedded DisplayPort as an internal interface instead of LVDS. LVDS still is the most popular industrial LCD display interface. All the internal image transfer interfaces like MIPI, Vx1 and eDP are variations of LVDS, where the protocols and the signals are a little bit different. For example, for eDP we can have lower noise and reduced power consumption. All of them have advantages over regular LVDS, but they are all LVDS type.

Now, let’s take a closer look at external interfaces. Those are the ones that we usually have direct access to. It can be TV or monitor connected to your computer with the HDMI . It can be a DVI usually used for monitors. Or VGA which is an outdated image interface for monitors.  The DisplayPort that is a HDMI successor. Finally, an universal USB-C, the most common interface nowadays used to connect devices.

Let us start with USB-C, the most universal interface . It is one of the best interfaces that we have ever designed, because it is really fast and also very universal. It not only transfers data, not only it is fast enough to transfer image, but it can also transmit a lot of power.

USB-C transmits up to 100 watt of power, because you can increase voltage and current. In a regular USB it is usually 5 volt and 0.5 or 1.0 amp, so only a couple watts. In USB-C you increase the voltage up to 20 volt and with the 5 amp current, so in total it’s even 100 watt of power.  This interface is made not only for data, but for real power transfer. Through USB-C you can charge your phone and your laptop. If you buy a new laptop right now, you may even not get a regular power connector, but only an USB-C. The USB-C is a very smart interface. If you connect the devices, they can negotiate with each other which one has more power. For example, if we connect a charger to a laptop, the charger has more power and will charge the laptop, but if you connect the laptop with the same interface to your mobile phone, then they will discuss the power levels, and of course the laptop will be charging the phone. You can already find monitors on the market that have USB-C instead of HDMI. Those monitors can be powered from your computer and need only one USB cable, both for image transfer and power.  For sure the future belongs to USB-C implementations.

Let’s move on to image transfer interfaces. The most common one is HDMI – High-Definition Multimedia Interface. M stands for Multimedia, because it transfers image with sound. If you connect your computer to your TV set with HDMI, you will need one cable for both the video and the audio. There are variations of HDMI connectors:

The next one is DVI – Digital Visual Interface. The first DVI was not a multimedia interface, because it did not have audio data transfer. Nowadays, there are some variations that can transfer audio, but it is non-standard. We can assume DVI is rather for image transfer. It is a digital interface, similar in signals to HDMI. The latest variation is DVI-I, where I stands for integrated interface. It can have a digital and analog part for VGA compatibility. In the picture above there is a DVI-D, digital only, where we do not have the pins for analog VGA interface. Analog VGA is sometimes available in your desktop computer, but not in laptops anymore.

The oldest video interface still in use  is the VGA – Video Graphic Array interface. It becomes less and less popular. This is an analog interface, not a digital one like all the other abovementioned interfaces. Analog interface means that we do not transmit the bits, but we send the voltages values. The analog signals are not stable, they are quite easy to disturb, so the transfer cannot be very high in speed and volume

The last external interface that we can find in our devices nowadays is a DisplayPort. DisplayPort is similar to HDMI or DVI. It can also transfer image and sound. It is even faster than the HDMI. Usually, the DisplayPort is used for high resolution displays, for new monitors and TVs with 4K or 8K resolution where it is really hard, or nearly impossible, to achieve such resolution using HDMI interface.

The μLCD43(GFX) is an intelligent graphics display that harnesses the power of Active Matrix LCD (TFT) technology to deliver a diverse range of features in a single, compact cost effective unit. Embedded at the heart of the design is the PICASO-GFX2 processor.

4DGL allows the developer to write applications in a high level syntax similar to popular languages such as BASIC, C and Pascal and run it directly on the PICASO-GFX2 processor embedded in the uLCD-43 module. It allows the user to take complete control of all available resources on that hardware platform such as the Serial Ports, Graphics LCD Display, uSD memory card, I/O pins, etc. This eliminates the need for an external host controller/processor to drive the uLCD-43 module via serial commands. It provides the user complete control over the hardware module allowing them to quickly develop powerful applications.

The parallel interface typically controls the LCD via 8 data pins and 3 control lines. The control lines used are Enable (E), Register Select (RS), and Read/Write (R/W). RS tells the LCD module if the information being sent is an Instruction or Data. The Enable tells the LCD module that the data or instruction in the register is ready to be interpreted by the LCD Module. Some controllers may have more than one Enable Control Line. The Read/Write tells the module whether to write data or read data from the register.

Serial LCD controllers typically have one Serial Data Line that writes data and cannot read. Normally, a Register Select Line(Sometimes designated A0) is used to tell the controller whether the incoming data is display information or a controller command

SPI, or Serial Peripheral Interface bus, is a synchronous (data is synchronized to the clock) serial data link standard that operates in full duplex mode, which means that devices that can communicate with one another simultaneously. To do this, two data lines are required. With this standard, devices communicate in a master/slave mode, where the master device (host processor) initiates the data and the clock. The LCD module is the (or one of the) peripheral slave device(s) attached to the data bus. Multiple peripherals (display modules and other devices) are addressed on the same serial data bus. However, the LCD module will only listen to the data it sees when the Chip Select line is active (usually low). If the Chip Select line is inactive (usually High), the LCD module listens to the data on the bus, but ignores it. The SDO line is not active when this state occurs. The SPI bus is comprised of four logic signals, two control lines and two data lines and is commonly referred to as SPI (4 wire).

Occasionally, SDI (serial data in) may be called out as MOSI (Master Out Slave In) from Motorola"s original name for these lines and MISO (Master In Slave Out) for SDO. The chip select line may be alternatively labeled SS (Slave-Select), or STE (Slave Transmit Enable). SPI is sometimes referred to as National Semiconductor"s trademark Microwire, which is essentially a predecessor of SPI, which only supports half duplex.

With CS (Chip-Select) the corresponding peripheral device is selected by the LCD Controller. This pin is mostly active-low. In the unselected state the SDO lines are hi-impedance and therefore inactive. The clock line SCL is brought to the device whether it is selected or not. The clock serves as synchronization of the data communication.

The chip select signal CS is optional for a single device system, because you could tie the CS input at the LCD Module low, if the other lines are dedicated to SPI use. This is sometimes called a 3 Wire SPI Interface.

Since the SPI interface protocol is a de facto standard, many variations of the standard protocol are used. For instance, chip manufacturers may use some of the parallel data lines when configuring the IC driver chip for serial communication. chip manufacturers may use some of the parallel data lines when configuring the IC driver chip for serial communication.

I2C uses only two bi-directional lines, Serial Data Line (SDA) and Serial Clock (SCL), which are both typically pulled up with resistors. Typical voltages used are +5 V or +3.3 V. One of the strengths of the I2C interface is that a micro can control multiple devices with just the two I/O pins and software. Because of the I2C design, it is only half-duplex. The interface generally transmits 8-bit words, sending the most significant bit first.

Connector ports for devices such like cameras, displays, basebands, and RF interfaces are standardized under MIPI Alliance specifications. These specifications include design, manufacturing costs, structural complexity, power consumption and degree of EMI.

We provide a comprehensive range of 5.6 TFT with RS 232 Interfacewhich are manufactured using modern technology and high grade quality materials. These are mostly used in various areas consists of televisions, personal computers, medical equipments and hand held instruments. We supply these at large scales and are highly demanded in the markets. Our range comprises of control board and black light unit.

LCD can’t be driven with DC (Direct Current), it has to be driven with AC (Alternative Current) and the overall current has to be ZERO. Otherwise, the Liquid Crystal Material will be damaged sooner or later.

The Controller IC receives data written in ASCII or JIS code from the MPU and stores this data in RAM. This data is then converted into serial character patterns and transferred to the LCD driver IC.

MCU interface include two types, 6800 and 8080. 8080 is the much more popular than 6800. Generally, MCU interface consist of 4/8/9/16bits data (like DB0, DB1, , , DB7; Note: 8bits is the most popular bits width), CS (chip select), RS (data register or instruction register select), RD (read enable), WR (write enable).

RGB interface often been used in control large-scale high-resolution LCD display. It include 6/16/18bits data (like R0, R1, , , G0, G1, , ,B0, B1, , , ), VSYNC (Vertical synchronization), HSYNC (Horizontal synchronization).

Aimed at reducing the cost of display controllers in a mobile device. It is commonly targeted at LCD and similar display technologies. It defines a serial bus and a communication protocol between the host (source of the image data) and the device (destination of the image data)

DisplayPort (DP) is a digital display interface developed by a consortium of PC and chip manufacturers and standardized by the Video Electronics Standards Association (VESA). The interface is primarily used to connect a video source to a display device such as a computer monitor, and it can also carry audio, USB, and other forms of data.

DisplayPort was designed to replace VGA, DVI, and FPD-Link. The interface is backward compatible with other interfaces, such as HDMI and DVI, through the use of either active or passive adapters. It is mostly used for larger size and higher resolution displays.

A universal asynchronous receiver/transmitter (UART) is a block of circuitry responsible for implementing serial communication. Essentially, the UART acts as an intermediary between parallel and serial interfaces. On one end of the UART is a bus of eight-or-so data lines (plus some control pins), on the other is the two serial wires – RX and TX.

A Universal Serial Bus (USB) is a common interface that enables communication between devices and a host controller such as a personal computer (PC). It connects peripheral devices such as digital cameras, mice, keyboards, printers, scanners, media devices, external hard drives and flash drives. There have been four generations of USB specifications: USB 1.x, USB 2.0, USB 3.x and USB4.

HDMI (High-Definition Multimedia Interface) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.

RS232 is a standard protocol used for serial communication, it is used for connecting computer and its peripheral devices to allow serial data exchange between them. As it obtains the voltage for the path used for the data exchange between the devices.

RS-232, when compared to later interfaces such as RS-422, RS-485 and Ethernet, has lower transmission speed, short maximum cable length, large voltage swing, large standard connectors, no multipoint capability and limited multidrop capability. In modern personal computers, USB has displaced RS-232 from most of its peripheral interface roles. Few computers come equipped with RS-232 ports today, so one must use either an external USB-to-RS-232 converter or an internal expansion card with one or more serial ports to connect to RS-232 peripherals. Nevertheless, thanks to their simplicity and past ubiquity, RS-232 interfaces are still used—particularly in industrial machines, networking equipment, and scientific instruments where a short-range, point-to-point, low-speed wired data connection is fully adequate.

SainSmart 3.2" TFT LCD Displayis a LCD touch screen module. It has 40pins interface and SD card and Flash reader design. It is a powerful and mutilfunctional module for your project.The Screen include a controller SSD1289, it"s a support 8/16bit data interface , easy to drive by many MCU like STM32 ,AVR and 8051. It is designed with a touch controller in it . The touch IC is ADS7843 , and touch interface is included in the 40 pins breakout. It is the version of product only with touch screen and touch controller.