mipi dsi lcd panel datasheet free sample

MIPI DSI has been widely adopted. It is ubiquitous in smartphones and also being used in tablets, laptops and laptop/tablet hybrids. It is also being implemented by the automotive industry for dashboard displays and in-car infotainment systems, and used in wearables, IoT and virtual/augmented reality applications.

MIPI DSI operates on the MIPI D-PHY physical layer. It uses a command set defined in the MIPI Display Command Set (MIPI DCS). It also incorporates the Display Stream Compression (DSC) Standard from the Video Electronics Standards Association (VESA). Overall, the feature set of MIPI DSI is quite similar to that of the more recent MIPI DSI-2℠ specification, which offers support for both MIPI D-PHY℠ and MIPI C-PHY℠.

First, you need to check whether this display has On-cell or In-cell touch panel, if has, it only needs to add a cover glass on it. If not, it needs an external touch panel.

Because the shape of the cover glass depends on the design of the clients, to avoid infringement of appearance, most of the developers need different customized touch panels.

37.72x49.86mmResolution=480x640"Display Type=IPS"Brightness=700-999 Nits (Sun-readable)"Touch Panel=None"CTP Controller=None"Operating Temperature=-30C to 80C"Specifications=/content/E104RB-FW450-N_Spec.pdf"Interface=2-Lane MIPI DSI

FIGURE 1. The MIPI Alliance has defined a plethora of interfaces for use in mobile devices. This article focuses on the Display Serial Interface (DSI) shown in the upper left corner.

The MIPI Alliance is a consortium of mobile device manufacturers and electronics components vendors that was established in 2003 to specify a common set of interfaces for various sub-systems within smartphones and similar multimedia devices. They have published a range of standards covering interfaces to audio, camera, display, touchscreen and other devices as shown in their infographic (Figure 1).

One of these, the Display Serial Interface, or DSI, standard is starting to appear on readily available microcontrollers (MCUs) and displays. I have recently embarked on my first project that uses this interface, so it’s worth sharing some of what I have learned in the process.

The DSI is a high-speed serial interface between a host processor and a display module. It is designed for low pin count, high bandwidth and low EMI. We will focus on the basic features of the DSI physical layer, called the D-PHY and touch briefly on the next layer up, the Display Command Set or DCS. Figure 2 shows two ways DSI can be used. It can operate in video mode where RGB pixel data and horizontal and vertical sync signals provided by the display controller are encoded into the serial stream by the DSI Host and decoded by the Device to drive the display glass. Alternatively, if the display controller and graphics RAM are integrated into the display, DSI can operate in command mode where data being written by the MCU into the RAM is encoded on the interface. In either mode commands from the DCS can be transmitted to configure the display.

FIGURE 2. The DSI interface can operate in two modes – video mode in which the pixel data and synchronization signals are streamed to the display in real-time, and command mode in which pixel data is written to the graphics RAM integrated with the display controller in the display module.

The two data lane zero line, D0P and D0N, can take one of four states, LP-00, LP-01, LP-10 and LP-11. Certain sequences of these states are used to switch between three possible modes – control mode, high-speed transmission, and escape mode. Control mode is the idle state from which the other states begin and end. On power-up the DSI is in control mode and the LP-11 idle state.

There is a lot more to the MIPI DSI interface that we don’t have space for here. This overview has hopefully given you a flavour for this interesting interface. It is a lot more complex than the classic parallel RGB plus clock and sync signals, but it requires a lot fewer pins and is capable of much higher bandwidth and therefore driving larger, high resolution displays.

6) Power on the Raspberry Pi and wait for a few seconds until the LCD displays normally. And the touch function can also work after the system starts.

The Display Serial Interface (DSI) is a specification by the Mobile Industry Processor Interface (MIPI) Alliance 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, the source of the image data, and the device which is the destination. The interface is closed source, which means that the specification of the interface is not open to the public. The maintenance of the interface is the responsibility of the MIPI Alliance. Only legal entities (e.g. companies) can be members. These members or the persons commissioned and approved by them have access to the specification in order to use it in their possible applications.

At the physical layer, DSI specifies a high-speed (e.g. 4.5Gbit/s/lane for D-PHY 2.0differential signaling point-to-point serial bus. This bus includes one high speed clock lane and one or more data lanes. Each lane is carried on two wires (due to differential signaling). All lanes travel from the DSI host to the DSI device, except for the first data lane (lane 0), which is capable of a bus turnaround (BTA) operation that allows it to reverse transmission direction. When more than one lane is used, they are used in parallel to transmit data, with each sequential bit in the stream traveling on the next lane. That is, if 4 lanes are being used, 4 bits are transmitted simultaneously, one on each lane. The link operates in either low power (LP) mode or high speed (HS) mode. In low power mode, the high speed clock is disabled and signal clocking information is embedded in the data. In this mode, the data rate is insufficient to drive a display, but is usable for sending configuration information and commands. High speed mode enables the high speed clock (at frequencies from tens of megahertz to over one gigahertz) that acts as the bit clock for the data lanes. Clock speeds vary by the requirements of the display. High speed mode is still designed to reduce power usage due to its low voltage signaling and parallel transfer ability.

The communication protocol describes two sets of instructions. The Display Command Set (DCS) is a set of common commands for controlling the display device, and their format is specified by the DSI standard. It defines registers that can be addressed and what their operation is. It includes basic commands such as sleep, enable, and invert display. The Manufacturer Command Set (MCS) is a device-specific command space whose definition is up to the device manufacturer. It often includes commands required to program non-volatile memory, set specific device registers (such as gamma correction), or perform other actions not described in the DSI standard. The packet format of both sets is specified by the DSI standard. There are Short and Long Packets, Short Packet is 4 bytes long; Long Packet can be of any length up to 216 bytes. Packets are composed of a DataID, Word count, Error Correction Code (ECC), Payload and Checksum (CRC). Commands that require reading data back from the device trigger a BTA event, which allows the device to reply with the requested data. A device cannot initiate a transfer; it can only reply to host requests.

Started a new project at work. We have to interface a 3.5 inch MIPI DSI TFT LCD to a Raspberry Pi (RPi) Compute Module 4 (CM4). The specific display is: https://focuslcds.com/product/3-5-tft-d ... b-mw420-n/

I have programmed microcontrollers to drive I2C, SPI, and parallel interface LCDs with 8 to 24bpp, easy to do. I have not programmed a computer running Linux to drive a display. So I don"t even know what questions to ask, so sorry if this info has been repeated before.

Is there any post or documentation anyone can point me to to get started? I can write the C code, the LCD supplier has a sample of initialization code, and I have written simple Linux scripts on the Pi. I just need to know the steps I need to take so I can break it down in to smaller chunks.

Have a look at https://github.com/raspberrypi/linux/bl ... verlay.dts and/or https://github.com/raspberrypi/linux/bl ... verlay.dts to get an idea what MIPi driver looks like.

From those it seems to look like 6by9 was adding ili9806e DSI support to the kernel. Does preparing for upstream mean that it might get included in to the kernel?

I"m no expert at MIPI DSI so yes this will be difficult. I"m an Embedded Engineer, I work with microcontrollers and interfacing them to various external peripherals including TFT LCDs. I"ve done USB and Wi-Fi bootloaders and those look easy compared to DSI.

It should be possible to extend it for other panels with alternate init sequences, but it won"t be merged until someone has taken it and confirmed that it works.

I did look at you ili9806e code for using SPI: https://github.com/6by9/linux/blob/rpi- ... ili9806e.c. I already know what I need to change there for using the controller in DSI mode so I thought I could start there. What would replace the SPI specific code? I know this is basic but does the Pi send commands to the display through DSI?

He sold management on the LCD I linked. I have found several hundreds of these displays, though I am told we should have 1000 of them. It was a planned production run, but circumstances have delayed it.

He sold management on the LCD I linked. I have found several hundreds of these displays, though I am told we should have 1000 of them. It was a planned production run, but circumstances have delayed it.

When looking for support you should keep in mind that people will struggle to support without having the display HW on hands (only a few have access to DSI analyzers ...), as one needs to see sometimes what is happening on the screen

My original question was what order do I start the development and were there any online resources I missed. You provided good information and a few links which is what I was asking to know, thank you. I have no other engineers to discuss this with and no MIPI consultants near by to "consult" with on the project. So any information is appreciated. Without the HW on hand I know others cannot assist. I am not asking for anyone to develop the project.

6by9 pointed me to his ili9806e SPI driver work, plus I have basic initialization code for the display. I"ve written most of the missing driver functionality. Once it can compile and the Pi attempts to run the display, then I will look into getting a MIPI DSI analyzer (Teledyne LeCroy or Keysight seem to be the major brands). I know they are expensive, but since I am going to be doing more projects with MIPI DSI it will be useful/required.

sure, you can, but as the official display is not a DSI - it is using a MIPI DSI to RGB chip - there are better resources which you"ve been pointed to already

6by9 pointed me to his ili9806e SPI driver work, plus I have basic initialization code for the display. I"ve written most of the missing driver functionality. Once it can compile and the Pi attempts to run the display, then I will look into getting a MIPI DSI analyzer (Teledyne LeCroy or Keysight seem to be the major brands). I know they are expensive, but since I am going to be doing more projects with MIPI DSI it will be useful/required.

The SPI driver is probably a dead end, at least initially. Get it working as a standalone DSI driver, and once working look at combining SPI config for DPI, and DSI into the one driver.