LCDInfo USBD480-WQ43 Manuel utilisateur
USBD480-WQ43 User Guide
Preliminary
Version 0.2
www.lcdin o.com
USBD480-WQ43 User Guide
Table of Contents
1. Introduction......................................................................................................................................4
Overview..........................................................................................................................................4
Features............................................................................................................................................4
. Physical Characteristics....................................................................................................................5
3. Electrical Characteristics..................................................................................................................5
4. USBD480-WQ43 module................................................................................................................6
5. Pin descriptions................................................................................................................................7
USB connector – J3.........................................................................................................................7
GPIO connector – J4........................................................................................................................7
6. Getting started..................................................................................................................................8
Connecting the display module........................................................................................................8
7. Programming interface.....................................................................................................................8
Overview..........................................................................................................................................8
Framebuffer memory addressing.....................................................................................................8
Pixel format......................................................................................................................................8
Windows API DLL..........................................................................................................................8
Linux framebuffer driver.................................................................................................................9
Linux X.Org driver..........................................................................................................................9
Direct USB device access................................................................................................................9
Other interfaces................................................................................................................................9
8. Direct USB command interface......................................................................................................10
Overview........................................................................................................................................10
Vendor requests.............................................................................................................................10
SET_ADDRESS 0xC0..........................................................................................................10
SET_FRAME_START_ADDRESS 0xC4.............................................................................11
GET_DEVICE_DETAILS 0x80............................................................................................11
SET_BRIGHTNESS 0x81.....................................................................................................11
SET_CONFIG_VALUE 0x8 ...............................................................................................1
GET_CONFIG_VALUE 0x83..............................................................................................1
GET_SAVED_CONFIG_VALUE 0x86................................................................................1
SAVE_CONFIGURATION 0x84..........................................................................................13
SET_TOUCH_MODE 0xE ..................................................................................................13
SET_STREAM_DECODER 0xC6.........................................................................................13
Configuration parameters..............................................................................................................14
TOUCH_MODE .................................................................................................................14
TOUCH_DEBOUNCE_VALUE 3.........................................................................................14
TOUCH_SKIP_SAMPLES 4.................................................................................................14
TOUCH_PRESSURE_LIMIT_LO 5.......................................................................................15
TOUCH_PRESSURE_LIMIT_HI 6.......................................................................................15
BACKLIGHT_BRIGHTNESS 0..........................................................................................15
USB_ENUMERATION_MODE .......................................................................................15
Bulk endpoint.................................................................................................................................16
Stream decoder..............................................................................................................................16
WRITE 0x5B41....................................................................................................................16
FRAMEBASE 0x5B4 .........................................................................................................17
WRAPLENGTH 0x5B43......................................................................................................17
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9. Touchscreen interface.....................................................................................................................18
10. Appendix A – Dimensional drawings..........................................................................................19
11. Document revision history........................................................................................................... 0
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1. Introduction
Overview
The USBD480-WQ43 is a 4.3” TFT display with USB interface. The controller board provides
framebuffer functionality and offers a Hi-Speed USB .0 interface for connecting to the host
system.
USBD480 provides a quick and easy to way to add a display to systems that have USB host ports.
The host system can be an embedded device or a PC computer. For best performance a Hi-Speed
(480 Mbps) USB host capability is recommended.
It is also possible to use the display as an input user interface with the optional touchscreen.
Features
•4.3" 480x 7 pixel resolution color TFT LCD
•Optional touchscreen
•Hi-Speed USB interface 480 Mbps
•16 bit colors (RGB565)
•8 MB framebuffer memory (available for double buffering etc.) 1)
•Display can be updated at 80-90 full frames per second over USB )
•USB powered
•User configurable startup image
•Custom versions of the controller board possible for different display panels
Note:
1. For custom applications support for larger framebuffer sizes has been implemented
. If required by the application it would be possible to increase the speed at the expense of
some increased power consumption
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2. Physical Characteristics
Item Specifications Unit
Display resolution 480 x 7 dot
Screen size 10.9 (4.3” type) diagonal cm
Active area 95.04(H) x 53.856(V) mm
Pixel pitch 0.198 x 0.198 mm
Unit outline dimensions 1) 1 0(W) x 67. (H) x ___(D) mm
Weight 90 (Typ.) g
Backlight type LED
Note:
1. Includes mounting tabs
3. Electrical Characteristics
Parameter Symbol Min. Typ. Max. Unit
Supply Voltage VCC 4.75 5.0 5. 5 V
Current Consumption without backlight 1) mA
Backlight Current Consumption full brightness mA
Note:
1. Including LCD panel, USB data transfer in progress
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4. USBD4 0-WQ43 module
For more details see dimensional drawings in Appendix
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5. Pin descriptions
USB connector – J3
The USB connector is used as the communication interface and the power supply for the display
module. The connector used is a mini USB B type connector. When connecting the display some
care should be taken to use a good quality USB cable.
Pin Name Function
1 VBUS +5 VDC
D- Data -
3 D+ Data +
4 NC Unconnected
5 GND Ground
GPIO connector – J4
0 way 0.5 mm pitch FFC/FPC connector.
Pin Name Function
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6. Getting started
Connecting the displa module
The USB connector is used as the communication interface and as the power supply for the display
module. The connector used is the common mini USB B type connector. When connecting the
display some care should be taken to use a good quality USB cable.
7. Programming interface
Overview
USBD480 is a composite USB device with two interfaces. First interface is for the main display
functionality and the second interface is for touchscreen input.
Framebuffer memor addressing
The controller has 8 MB of memory available for storing the image data. The memory size of 4096
x 56 x 16 bits makes for a total of 1048576 different addresses, 16 bits of data per address. One
frame requires 480 x 7 x = 611 0 bytes of memory. This means that it is possible to store 3
separate full frames of image data to the controller memory. Aligning the start address for each
frame to the 51 byte boundaries results in a bit more efficient memory bandwidth use.
Double buffering can be implemented using two alternating frames in the memory. The actual
address change for the SET_FRAME_START_ADDRESS command is synchronized with VSYNC
in the controller hardware.
It is also possible to implement hardware accelerated vertical scrolling by first filling the controller
memory with video data and then just changing the frame start address to scroll the image.
Pixel format
The USBD480 controller uses the RGB565 pixel format. One pixel consists of 16 bits of data – 5
bits red, 6 bits green and 5 bits blue. This results in 65536 different colors.
R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0
Windows API DLL
For Windows there exists a DLL interface that provides an API that can be used for accessing the
display. When using the DLL it is not necessary to know the low level details of accessing the USB
device. The DLL also automatically detects and uses the available USB driver installed in the
system. The currently available options for the USB driver are Libusb or the UMDF USB driver.
Two alternative drivers make it possible to support a wider range of Windows versions and with the
DLL automatically detecting the driver the user doesn't need to know which one is installed in the
system.
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The API interface is described in a separate document.
Linux framebuffer driver
When Linux is used one possible way to access the display is to use the USBD480 framebuffer
kernel driver. This driver makes the USBD480 display appear as a normal Linux framebuffer
device (/dev/fb) which is used by many existing libraries for accessing display hardware. Qt
Embedded and SDL included for example. The driver also connects the touchscreen to the Linux
input API.
Linux X.Org driver
Direct USB device access
Direct access to the USB device is also possible if it is preferred instead of the existing library or if
the platform used doesn't have existing support libraries.
Other interfaces
There are also other libraries and drivers being developed that support using the USBD480
controller. See the website for more details about what is currently available. Also feel free to give
feedback if your application would need something different from the currently available offerings.
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. Direct USB command interface
Overview
The display is controlled by sending USB vendor requests to the control endpoint. For image data
transfer bulk endpoints are used.
Another option is using the bulk endpoint exclusively for image data transfer and related
commands. This is possible using the stream decoder feature.
Vendor requests
SET_ADDRESS 0xC0
SET_FRAME_START_ADDRESS 0xC4
GET_DEVICE_DETAILS 0x80
SET_BRIGHTNESS 0x81
SET_CONFIG_VALUE 0x8
GET_CONFIG_VALUE 0x83
GET_SAVED_CONFIG_VALUE 0x86
SAVE_CONFIGURATION 0x84
SET_TOUCH_MODE 0xE
SET_STREAM_DECODER 0xC6
SET_ADDRESS 0xC0
This request sets the write address to the framebuffer.
bRequest wValue wIndex wLength Data
SET_ADDRESS Bits 15 to 0 of
the address
Bits 1 to 16 of
the address
0 None
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Table des matières
