DSI ShieldQuick Start Guide

April 2016, rev 1.0

Table of Contents1.Introduction...............................................................................................................................................................32.Features.......................................................................................................................................................................33.Supported displays..................................................................................................................................................34.Board overview.........................................................................................................................................................3

HDMI Video Input.............................................................................................................................................. 4Composite Video Input..................................................................................................................................... 4USB Connector.................................................................................................................................................... 4Arduino Pinhead Connectors.......................................................................................................................... 4JTAG Connector.................................................................................................................................................. 4Iphone 4 LCD connector................................................................................................................................... 4LG E980/Expansion connector.......................................................................................................................5

5.Connecting the displays........................................................................................................................................56.Configuring the board............................................................................................................................................67.Frequently Asked Questions..............................................................................................................................7

Which HDMI sources the board works with?..............................................................................................7My image is displayed in portrait mode. Is it possible to rotate it?.........................................................7How do I get the DSI Shield to work with a Raspberry Pi?........................................................................7Is HDCP supported?........................................................................................................................................... 8Can the device drive QHD (2560x1440) panels?......................................................................................8Can it be used with a panel type X?................................................................................................................8

8.Appendix: Configuring Raspberry Pi to work with the DSI Shield.....................................................8

1. Introduction

The DSI Shield is an Arduino shield that drives LCD and AMOLED displays equipped with a MIPI DSI interface. Such displays are commonly used in smartphones and other portable devices.

2. Features

The current version of the firmware (v2.0) provides the following features:

• Conversion from HDMI to MIPI DSI, allowing to connect a MIPI DSI display to a range of devices with HDMI outputs.

• General-purpose FPGA development board with a MIPI DSI interface.

3. Supported displays

The displays currently supported by the DSI Shield are listed in Table 1.

Table 1. Supported panel types

Panel type Technology Used in Resolution Refresh rate

LH350WS02-SD02 LCD Iphone 4/4S 640 x 960 (portait) 60 Hz

LH550WF1-SD01 LCD LG Optimus E980 1080 x 1920 (portrait)

48 Hz

4. Board overview

The DSI Shield layout is shown in Figure 1.

Figure 1. Overview of the DSI Shield and its connectors.

HDMI Video Input

The HDMI video input features a standard (full size) HDMI Type A connector. HDCP, CEC or HDMI audio are not supported.

Composite Video Input

The Composite Video input is reserved for use in the future versions of the firmware, which will feature conversion between composite video and MIPI DSI.

USB Connector

The USB connector is used to supply power to the device (the USB host port must support sourcing 500 mA of current). It also provides a USB serial port device enabling the user to configure the DSI Shield through a standard serial port terminal.

Arduino Pinhead Connectors

Standard Arduino pinheads. Reserved for use in the future versions of the firmware, which may feature graphics functions for Arduino.

JTAG Connector

The JTAG Connector provides a 3.3-Volt JTAG interface to the Spartan-6 FPGA. The pinout of the connector is shown in Figure 2.

Figure 2. Pinout of the JTAG Connector.

Iphone 4 LCD connector

The 28-pin, 0.4 mm pitch Iphone 4 connector allows for direct interfacing with an Iphone 4 LCD.

LG E980/Expansion connector

The 30-pin, 0.4 mm pitch E980 connector allows for direct interfacing with an LG Optimus E980 LCD. It is also foreseen for mezzanine board adapters for other display types, which will be supported by future versions of the firmware.

5. Connecting the displays

To connect the display, please follow these steps:

• Power off the board (disconnect USB cable).• Connect the Iphone4 LCD to the Iphone4 connector as shown in Figure 3.• (or) connect the E980 LCD to the E980/Expansion connector, as shown in Figure 4.

Note that the E980 screen is facing the desk.• Power on the board (connect USB cable).• Follow the configuration procedure, described in Chapter 6.

Note: The DSI Shield supports one LCD connected at a time.

Figure 3. Connection of the Iphone4 LCD.

Figure 4. Connection of the LG E980 LCD.

6. Configuring the board

Configuration of the board currently requires choosing the display type & desired brightness in the configuration menu accessible through the USB port:

• Make sure you have FTDI's USB to Serial Port converter drivers installed. These can be downloaded from the FTDI's website.

• Connect the display to the DSI Shield.• Connect the DSI Shield to the PC with a mini-USB cable.• Open a serial terminal on the USB serial port of the DSI Shield. The transmission

parameters are 115200 bps 8N1 (8 data bits, no parity, 1 stop bit). Figure 5 shows an example setup of the PuTTY Serial terminal.

• Press any key. A configuration menu shown on Figure 6 will appear. You can navigate through the menu using up/down arrow keys.

• Select Select display type option. Browse through the available display list using left/right arrow keys to select your LCD panel type.

• Select Save settings & restart option and press Enter key.• The Device info option shows the list of supported displays and the firmware

version/build info (example in Figure 7).• If everything went fine, you should see a No HDMI Signal screen (example in Figure 8)

on your LCD. Connect the Shield to the PC using a HDMI cable. The computer should automatically detect the display type and adjust the resolution accordingly.

Figure 5. Example PuTTY serial port configuration.

DSI Shield Setup (up/down to navigate, left/right to adjust)

Select display type      : LH550WF1­SD01 (LG E980)  Adjust brightness        : [################################] 100%  Device info              Save settings & restart 

Figure 6. Main configuration menu.

DSI Shield Device Info 

Firmware version: v1.0­rc2, built on Jan  5 2016, 15:53:56 Supported displays: ­ LH550WF1­SD01 (LG E980) (1080x1920, DSI 4­lane, 650 MBps/lane, 47 Hz refresh ­ LH350WS02 (Iphone4/4S) (640x960, DSI 3­lane, 387 MBps/lane, 62 Hz refresh 

Figure 7. Device info menu

Figure 8. Example No-signal screen.

7. Frequently Asked Questions

Which HDMI sources the board works with?

Any device which understands and respects the EDID (Extended Display Identification Data)standard. EDID is a small EEPROM memory containing a descriptor of the video timings supported by the display. Since most DSI panels are portrait and default display modes used by most video sources are landscape, the DSI shield provides custom timing parameters that must be respected by the source device. This is true for most PCs (Mac, Linux, Windows), butother devices, such as gaming consoles or Blu-Ray players may not respect the EDID and therefore are unable to work with the DSI shield.

My image is displayed in portrait mode. Is it possible to rotate it?

Yes, but your source device must support rotation. Most PC video cards as well as the Raspberry Pi support display rotation. Rotation can be usually enabled in the Display Options of your operating system.

How do I get the DSI Shield to work with a Raspberry Pi?

You need to edit the Raspi's configuration file (config.txt on the boot partition of your SDcard). See the Appendix for configuration details.

Is HDCP supported?

No. Using HDCP requires a non-disclosure agreement, something we cannot allow in an Open Hardware project.

Can the device drive QHD (2560x1440) panels?

No. Most of them have two separate MIPI ports (each of them responsible for one half of the panel). We have only one MIPI master. Future versions of the Shield may support such panels.

Can it be used with a panel type X?

Probably yes, if the panel is popular enough, speaks MIPI DSI and its documentation is

available. Please send us a request with the panel type.

8. Appendix: Configuring Raspberry Pi to work with the DSI Shield

Configuration instructions:

• Open the config.txt file on the SD card of your Raspi.

• Add the following lines:

For the IPhone4 LCD:hdmi_timings=640 1 62 14 62 960 1 27 1 17 0 0 0 60 0 48437500 1

display_rotate=1

framebuffer_width=960

framebuffer_height=640

For the E980 LCD:hdmi_timings=1080 1 46 1 45 1920 1 10 1 4 0 0 0 48 0 108330000 1

display_rotate=1

framebuffer_width=1920

framebuffer_height=1080

• Save the file.

• Reboot your Raspi with the DSI Shield connected.