Vinculum-II Scrolling Text Application Using LED dot matrix display

Vinculum-II Scrolling Text Application Using LED dot matrix display
Application Note
AN_200
Vinculum-II Scrolling Text
Application Using LED dot matrix
display
Version 1.0
Issue Date: 2012-02-09
This application note provides an example of using the FTDI Vinculum-II
(VNC2) to communicate with a USB Flash drive to display text and graphics
held on the Flash drive, on a LED dot matrix display. Drivers and source code
are also provided (downloadable from the FTDI website)
Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk, and the
user agrees to defend, indemnify and hold harmless FTDI from any and all damages, claims, suits
or expense resulting from such use.
Future Technology Devices International Limited (FTDI)
Unit 1, 2 Seaward Place, Glasgow G41 1HH, United Kingdom
Tel.: +44 (0) 141 429 2777 Fax: + 44 (0) 141 429 2758
Web Site: http://ftdichip.com
Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Table of Contents
1
2
3
4
Introduction .................................................................................................................................... 3
1.1
Overview ................................................................................................................................. 3
1.2
Hardware Requirements ......................................................................................................... 4
Operation ........................................................................................................................................ 5
2.1
Using VPlayer Display Software .............................................................................................. 5
2.2
Updating the SEQUENCE.TXT file ............................................................................................ 5
2.3
VPlayer application demonstration ........................................................................................ 6
Hardware ........................................................................................................................................ 7
3.1
Chipset .................................................................................................................................... 7
3.2
Interfaces ................................................................................................................................ 7
Firmware ......................................................................................................................................... 9
4.1
5
Source Code for the VNC2 Application Firmware ......................................................................... 10
5.1
6
7
vPlayerFlashDisk.C ................................................................................................................ 10
5.1.1
SPI_Master_Init ............................................................................................................. 10
5.1.2
main .............................................................................................................................. 10
5.1.3
Thread Flash Disk .......................................................................................................... 11
5.1.4
Thread displayOut ......................................................................................................... 13
Byte ordering in the frame buffer ................................................................................................. 15
6.1
2 bits per pixel colour palette ............................................................................................... 15
6.2
Display buffer format for 2 blocks ........................................................................................ 16
6.3
Display buffer format for a LED module ............................................................................... 16
6.4
Display buffer format for a LED panel................................................................................... 17
6.4.1
LED panel stacking ........................................................................................................ 17
6.4.2
LED column bit shifting direction .................................................................................. 18
6.4.3
rowData Array ............................................................................................................... 18
6.4.4
Bitmap file format ......................................................................................................... 20
VPlayer Display Software .............................................................................................................. 22
7.1
8
File Types................................................................................................................................. 9
Features supported ............................................................................................................... 23
Contact Information...................................................................................................................... 24
1
Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Appendix A – References ...................................................................................................................... 25
Document References....................................................................................................................... 25
Acronyms and Abbreviations ............................................................................................................ 25
9
Appendix B – LED module schematics (control board and dot matrix board) ............................. 26
Appendix C – List of Tables & Figures ................................................................................................... 32
List of Tables ..................................................................................................................................... 32
List of Figures .................................................................................................................................... 32
Appendix D – Revision History .............................................................................................................. 33
2
Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
1 Introduction
This application note describes an application that uses Vinculum-II to display text and graphics,
obtained from a bitmap file in a USB Flash drive, on a LED dot matrix display. This solution is
better than the conventional method of implementing the features in the firmware. In this method
all the features are implemented in the PC software which creates the bitmap file. The features
implemented in the PC software are; fonts, languages and graphics support. The firmware passes
the raw data in the USB Flash drive to the display with no processing on the data. For a given LED
panel the firmware is fixed and does not change for supporting multiple fonts, languages and
graphics. So it is easy to update the display by replacing the content in the USB Flash drive. The
figure below shows a Vinco Development Module used to display text on a LED dot matrix display
The source code for the application firmware is provided as an example and is neither guaranteed
nor supported by FTDI. The source code for the firmware can be downloaded from the following
location on the FTDI website: http://www.ftdichip.com/Support/FTSwExamples.htm
SPI and GPIO lines
SPI Master
Driver
VNCLOMB1A
www.ftdichip.co
m
GPIO driver
Vinculum II CPU
Debug and
Programming
interface
USB Flash Drive
Optional connection to PC
3v3 regulator
running Vinculum II IDE
USB Host (Port
2)
Debug
Interface
(for code development only)
Display and Vinco boards are both powered from a 5V supply (not shown)
Figure 1 : Vinco Development Module with LED dot matrix display
1.1 Overview
The VPlayer consists of a PC application used to generate the bitmap file, Vinculum-II firmware
and hardware interface to read data from the USB Flash drive and display on the LED dot matrix
display panel.
The firmware is written in C and developed using the Vinculum-II IDE.
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
PC
Software
Convert text
or graphics
into Bitmap
file
Bitmap file
contains the
bitmap data
which can be
played on LED
screen
USB Flash
Drive
Bitmap file is
copied from
PC to the USB
flash drive
Clearance No.: FTDI# 277
Vinco USB
Host
USB flash
drive is
connected to
Vinco USB
host
LED Panel
Firmware
reads the
bitmap files
and displays
the frames on
the LED
screen
Figure 2 : VPlayer Overview
The VPlayer is a project designed to demonstrate the capabilities of FTDI’s Vinculum-II (VNC2)
series of embedded USB host controllers. The PC application converts text messages, applying
optional effects to the text and saves it as a bitmap file on a USB Flash drive. The firmware reads
the bitmap data from the USB Flash drive and sends it to the dot matrix LED panel for display. This
can be used for advertising or displaying applications that requires various displaying effects.
1.2 Hardware Requirements
Vinco Development Module
VNC2 Debug Module
LED panel, 32x128 pixels (8 LED modules)
AC:DC converter & regulator (supplies 5V to LED panel)
Windows PC with Vinculum-II Tool chain installed
a USB 2.0 compliant A-mini-B cable
a FAT-formatted USB Flash drive
(See Appendix A for references to the datasheets and downloadable firmware and Appendix B for
LED module schematics)
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
2 Operation
The VPlayer has a PC application (VPlayer Display software) which is used to generate the bitmap
files. The display text is converted to a bitmap file in the VPlayer Display software. The bitmap
files are copied to a USB flash drive. A master file (SEQUENCE.TXT) is created in the USB flash
drive. The master file is a text file which has the sequence of the bitmap file names to be
displayed. The master file is edited to include all the bitmap files to be displayed in the sequence.
After the files are updated in the USB flash drive, the flash drive is removed from the PC and
connected to the Vinco USB host port. Vinculum-II firmware and hardware interface read data
from the USB Flash drive and display on the LED dot matrix display panel.
2.1 Using VPlayer Display Software
The following steps are required to create new bitmap files using VPlayer Display Software
1. Connect the USB Flash drive to the PC
2. Open the VPlayer Display Software
3. Enter the text in the text box and select the text colour.
4. Select the display type and click on the “Save Data File” button.
5. Save the bitmap data file to the USB Flash drive. The filename should be in 8.3 format
2.2 Updating the SEQUENCE.TXT file
The following steps are required to update the SEQUENCE.TXT file
1. Open the SEQUENCE.TXT file in the USB Flash drive using a text editor on PC (e.g.
wordpad, notepad).
2. Add the bitmap filename to the SEQUENCE.TXT.
3. If the bitmap filename is less than 8 characters then the filename in SEQUENCE.TXT has to
be padded with blank spaces. There should be only 1 bitmap filename in each line.
4. The content of the SEQUENCE.TXT file is provided as an example.
TCHISTATDAT<NEW LINE>
TCHIUP<SPACE><SPACE>DAT<NEW LINE>
TCHIBLNKDAT<NEW LINE>
SCHISTATDAT<NEW LINE>
SCHIUP<SPACE><SPACE>DAT<NEW LINE>
SCHIBLNKDAT<NEW LINE>
ENGSTAT<SPACE>DAT<NEW LINE>
ENGSTAT<SPACE>DAT<NEW LINE>
ENGUP<SPACE><SPACE><SPACE>DAT<NEW LINE>
ENGLEFT<SPACE>DAT<NEW LINE>
ENGLEFT<SPACE>DAT<NEW LINE>
ENGBLNK<SPACE>DAT<NEW LINE>
Note: The Period “.” Is not included in the string to separate the name from .DAT.
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
2.3 VPlayer application demonstration
The following steps are required for operation of VPlayer application demonstration
1. Apply power to the Vinco Development Module and the LED panel
2. Connect the USB Flash drive to USB Host port of the Vinco Development Module
3. The VNC2 will enumerate the USB Flash drive connected to the Vinco Development Module
4. The LED panel will display the text stored in the bitmap file in the USB Flash drive
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
3 Hardware
3.1 Chipset
The Vinculum-II VNC2 series of embedded USB Host / Slave controllers provide USB Host
capability for a variety of USB device classes including support for BOMS (bulk only mass storage),
Printer, HID (human interface devices). The VNC2 provides SPI, parallel FIFO and UART interfaces
to be active on the available pins through the use of an I/O Multiplexer. The IO Multiplexer also
configures the VNC2 IO pins as outputs which will be connected to the Dot Matrix 3mm/5mm bicolour LED Display panel. The GPIO and SPI Master drivers of Vinculum-II are used to control the
LED dot matrix display panel. The USB host port is used to attach a USB Flash drive. The figure
below shows Vinco Development Module and VNC2 Debug Module.
.
Figure 3 : Vinco Development Module with VNC2 Debug Module
3.2 Interfaces
SPI Master and GPIO – Communications between the Vinculum-II and LED display panel
USB Host – Reads display data from USB Flash drive
GPIO
Latch
CLK
SPI Master
Enable
A
C
Enable
Row 0
Data In
Data Out
B
GPIO
Output
Row 1
Row 2
Enable
To other
shift
registers
Debugger Interface – Program and debug the Vinculum-II with VPlayer firmware.
Shift
Registers
(256
outputs
in total)
Row 3
Row 4
Row 5
Vinco
To other row decoders
Row 6
Row 7
Row
decoder
LED Matrix
Figure 4 : LED Display driver and multiplexing
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
SPI CS
J4-10
CN1-4
SPI MOSI
J4-11
CN1-1
SPI CLK
CN1-2
J4-13
J4-14
VINCO
GND
CN1-5, CN1-6
D0
J6-8
CN1-8
D1
J6-9
LED
Module(refer
Appendix B)
CN1-7
D2
J6-10
CN1-10
ROW EN
J6-11
CN1-9
COL EN
J6-12
CN1-3
Figure 5 : Interfacing Vinco with LED dot matrix panel
8
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
4 Firmware
The firmware corresponds to the VNC2 firmware model defined in [4]. It consists of two threads:
Flash Disk is responsible for enumerating the USB Flash drive attached to the USB host and
reading bitmap data files; displayOut is responsible for sending the bitmap data to the LED
display panel. Dual buffers are used for storing data and access to the buffer is synchronised
using mutexes. The LED display works on the persistence of vision, the data has to be
continuously refreshed to the different rows. This is done using the dual buffer, when the Flash
disk thread is reading data into buffer1 the displayOut thread writes data to the LED panel from
buffer2 and vice versa.
The VPlayer firmware data flow is shown in Figure 6.
RG LED
dot matrix
Bitmap file
Flash
Disk
Buffer1
displayOut
Buffer2
Figure 6 : VPlayer Firmware data flow
The firmware is developed using the Vinculum-II IDE software. It is available free from the FTDI
website and has drivers, libraries and examples to help with application development. The SPI
Master and GPIO drivers are used to interface the Vinculum-II to the LED display panel.
4.1 File Types
There are 2 types of files to update the display content. The sequence of the display content
can be easily manageable without recreating each of the content.
Master file:
All the bitmap files are controlled by a master file (i.e. SEQUENCE.TXT) which has the information
on the sequence of displaying the different bitmap files.
Bitmap file:
The display data is stored in a bitmap file which has all the information. The bitmap file has the
information for switching ON and OFF all the LEDs in the LED panel in a single frame data. The
bitmap file size depends on the number of frame data to be displayed. 24 frames are displayed
every second.
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
5 Source Code for the VNC2 Application Firmware
This section is aimed at those wanting to learn about coding VNC2 devices or modifying the
existing project.
The firmware basic steps are:
1. Initialise device drivers
2. Define pin-outs
3. Open ports to be used
4. Configure ports to be used
5. Read/write data
6. Close ports
The VNC2 source code for this project can be viewed in appendix A and can also be downloaded
free from the FTDI website.
5.1 vPlayerFlashDisk.C
vPlayerFlashDisk.C is the main firmware file. This file is split into multiple functions.
void SPI_Master_Init(void);
void main(void);
void flashDisk();
void displayOut(void);
5.1.1
SPI_Master_Init
Configure the SPI master interface. The SPI interface is used to send the data to the LED column
drivers. The SPI clock is configured at 3MHz. The SPI clock frequency can be increased to 6 MHz,
above which the clock signal is distorted in the cables connecting the LED modules.
5.1.2
main
Configure the IO pins. Initialize the GPIO, SPI, USB host and BOMS class driver. Threads Flash
Disk and displayOut are created. Thread Flash Disk is linked to the function flashDisk and thread
displayOut is linked to the function displayOut. The VPlayer sample requires the following FTDI
provided components: USBHOST driver, BOMS driver, FAT driver, SPI Master driver, Timers driver,
GPIO driver and the VOS kernel.
The GPIO pins are used to control the row selection, row enable and the column enable of the LED
drivers. To select a particular row D0, D1, D2 has to be written with the row value and the ROWEN
is driven LOW.
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
5.1.3
Clearance No.: FTDI# 277
Thread Flash Disk
This thread enumerates the USB Flash drive, attached to the USB host port and loads the
BOMS class driver and the FAT file system driver.
It then checks for the master file SEQUENCE.TXT. This file has the sequence of the bitmap
files to display.
The bitmap files is opened and the bitmap data is read into buffer1 and buffer2.
Wait for data in buffer1 to be completely sent to the hardware. Then read the next block of
data into buffer1
Wait for data in buffer2 to be completely sent to the hardware. Then read the next block of
data into buffer2
Close the bitmap file after reaching End of File.
Read the next bitmap file in the SEQUENCE.TXT until all the files are read.
After reaching the end of file in the SEQUENCE.TXT the control transfers to the beginning
of the SEQUENCE.TXT
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
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Thread Flash Disk
Clearance No.: FTDI# 277
START
NO
Is USB Flash Drive
connected?
YES
Enumerate the USB Flash drive
Initialize the FAT file System
Is open SEQUENCE.TXT
successful?
NO
?
YES
Read the bitmap file name in SEQUENCE.TXT
Open the bitmap file fname.DAT
Read bitmap data into buffer 1 and buffer 2
NO
Is fname.DAT End Of
File reached?
YES
Close fname.DAT
Is SEQUENCE.TXT End
Of File reached?
NO
YES
Close SEQUENCE.TXT. Close FAT file system.
STOP
Figure 7 : Thread Flash Disk Flow Chart
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
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5.1.4
Clearance No.: FTDI# 277
Thread displayOut
This thread initializes the SPI master driver and timer driver.
It waits for the Flash Disk thread to finish reading data to buffer1.
It reads the data from the buffer1 and sends it to the dot matrix display panel through the
SPI Master write function.
It then turns the corresponding row driver, row enable and column enable using the GPIO
driver.
It waits for the Flash Disk thread to finish reading data to buffer2.
It reads the data from the buffer2 and sends it to the dot matrix display panel through the
SPI Master write function.
It then turns the corresponding row driver, row enable and column enable using the GPIO
driver.
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
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Thread displayOut
Clearance No.: FTDI# 277
START
Initialize SPI Master. Initialize Timer.
Row count = 7. Current buffer = BUFFER
1
NO
Is timer reached
1.736 millisecond?
YES
NO
Is DATA available on
current buffer?
YES
Turn OFF the row driver.
Latch data in shift register to column
driver. Turn ON the row driver.
SPI write 128 bytes to shift register.
Increment row count and current index
Is row count = 8
NO
YES
Reset row count
frame displayed 3 times?
NO
YES
NO
Is current index > =
BUFFER_SIZE?
YES
Current buffer = NEXT BUFFER. Row count = 7
STOP
Figure 8 : Thread displayOut Flow Chart
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
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Clearance No.: FTDI# 277
6 Byte ordering in the frame buffer
The VPlayer support displays with 2-bit colour. For all display buffer formats, the order of pixels on
the display is from left to right and from top to bottom. For example, pixel (0, 0) appears at the
upper left corner of the display, and pixel (width – 1, height – 1) appears at the lower right corner.
6.1 2 bits per pixel colour palette
The 2-bpp format is typically used for 4-entry palette colour displays. The following table shows
the bits for the associated palette entry.
Pixel (m,n),
Green
Pixel (m,n),
Red
Colour
palette
0
0
Black
1
0
Green
0
1
Red
1
1
Yellow
Table 1 : Pixel colour palette
Figure 9 : LED block (8x8 pixels)
A LED block has 8x8 pixels with 2 LED (RED and GREEN) in each pixel position. The number of
LEDs in a LED block is 128 (8*8*2).
15
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
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Clearance No.: FTDI# 277
6.2 Display buffer format for 2 blocks
The following table shows the byte arrangement of memory for each row in 2 blocks.
Byte 0
Bit 7
P00,
Green
----
Byte 1
Bit 0
Bit 7
P07,
P08,
Green
Green
----
Byte 2
Bit 0
Bit 7
P0F,
P00,
Green
Red
----
Byte 3
Bit 0
Bit 7
P07,
P08,
Red
Red
Bit 0
----
P0F,
Red
Table 2 : Pixel arrangement in the display buffer format for 2 blocks
6.3 Display buffer format for a LED module
MXG0/R0
MXG8/R8
Row 0
Row 1
Row 7
MXG63/R63
Figure 10 : LED module Pixel numbering
Bit shifting direction, G0 is the first bit shifted out, and R63 is the latest shifted out
in the row
M0
M0
M0
M0
M0
M0
M0
M0
G0-15
R0-15
G16-31
R16-31
G32-47
R32-47
G48-63
R48-63
Green
LED
Red LED
Green
LED
Red LED
Green
LED
Red LED
Green
LED
Red LED
M0 –module 0 ( refers to the LED module 0)
M0R0 - module 0 left most pixel red LED
M0G0 – module 0 left most pixel green LED
M0G63 - module 0 right most pixel green LED
M0R63- module 0 right most pixel red LED.
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
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MXG0 - first bit to be shifted out in a row,
MXR63 - last bit to be shifted out in a row,
MX - LED module Number
RY - Red LED column number
GY - Green LED column number
Figure 11 : LED module , data shift direction
6.4 Display buffer format for a LED panel
Figure 12 : LED Panel (32 x 64 pixels)
The size of the LED display panel of 32x128 pixels is 59.5cm x 16 cm x 7cm
6.4.1
LED panel stacking
LED block: consists of 8*8 dot pixel, each pixel has 1 red LED and 1 green LED
LED module: consists of 8 LED blocks in a row. It has row and column control signals
designed on control PCB.
LED panel: built with 8 LED modules in 4 * 2 arrays. Effectively, the LED panel consists
of 32 (row) * 128 (column) dual LED (1 red and 1 green LED in each pixel).
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
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6.4.2
Clearance No.: FTDI# 277
LED column bit shifting direction
In the LED panel, first row of all LED modules will be turned on at same time. The
controller will shift the data of row 0 of all LED modules before turn on the corresponding
row output.
M0R0/G0 corresponding to top most left pixel on LED module 0, M7G63/R63
corresponding to the right most bottom pixel. Module position can be referred to the
diagram below.
The shifting operation will shift all LED column bits of the same row of all LED modules
from module M7 to M0. Module 0 green LED 0 (M0G0) is the first bit to shifted out.
Detailed shifting sequence is in the frame bit map table below.
DATA OUT
LED Module 0
LED Module 1
LED Module 2
LED Module 3
LED Module 4
LED Module 5
LED Module 6
LED Module 7
DATA IN
Figure 13 : LED panel stacking
6.4.3
rowData Array
Byte 0 (bit 7 corresponding to M0G0 –
the first bit to be shifted out)
M0G[0-7] (M0G0 at bit 7, M0G1 at bit 6..)
Byte 1
M0G[8-15] (M0G8 at bit 7, M0G9 at bit 6..)
Byte 2
M0R[0-7]
Byte 3
M0R[8-15]
Byte 4
M0G[16-23]
Byte 5
M0G[24-31]
Byte 6
M0R[16-23]
Byte 7
M0R[24-31]
Byte 8
M0G[32-39]
Byte 9
M0G[40-47]
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Byte 10
M0R[32-39]
Byte 11
M0R[40-47]
Byte 12
M0G[48-55]
Byte 13
M0G[56-63]
Byte 14
M0R[48-55]
Byte 15
M0R[56-63]
Clearance No.: FTDI# 277
Byte 16 (starts module 1 bit map)
Byte 17 – byte 111
LED bit map for module 1 to 6
……
Byte 112
M7G[0-7]
Byte 113
M7G[8-15]
Byte 114
M7R[0-7]
Byte 115
M7R[8-15]
Byte 116
M7G[16-23]
Byte 117
M7G[24-31]
Byte 118
M7R[16-23]
Byte 119
M7R[24-31]
Byte 120
M7G[32-39]
Byte 121
M7G[40-47]
Byte 122
M7R[32-39]
Byte 123
M7R[40-47]
Byte 124
M7G[48-55]
Byte 125
M7G[56-63]
Byte 126
M7R [48-55] (M7R48 at bit 7, M7R47 at bit 6..)
Byte 127
M7R [56-63] (M7R56 at bit 7, M7R57 at bit 6..)
Table 3 : Byte arrangement in rowData Array
The table above shows the data ordering in rowData array.
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6.4.4
Clearance No.: FTDI# 277
Bitmap file format
The LED panel bitmap file format based on 8 LED modules per panel, stacking in 4 by 2.
The frame buffer contains the data for Row 0 to Row 7. The frame buffer has 128*8
bytes.
Structure BitmapFileFormat
{
Structure frameBuffer Data_Frame0
{
Structure rowBuffer Data_Row 0
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 1
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 2
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 3
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 4
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 5
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 6
{
rowData[128];// include the array in section 6.4.3 here
}
Structure rowBuffer Data_Row 7
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Clearance No.: FTDI# 277
{
rowData[128];// include the array in section 6.4.3 here
}
} /* end of Structure frameBuffer Data_Frame0 */
Structure frameBuffer Data_Frame1
{
...
}
Structure frameBuffer Data_Frame2
{
...
}
.
.
.
Structure frameBuffer Data_FrameN
{
...
}
} /* end of Structure BitmapFileFormat */
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
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7 VPlayer Display Software
Bitmap creation is done by VPlayer Display software in the computer.
Figure 14 : VPlayer Display Software
FTDI provide an example PC utility called VPlayer Display Software, which is used to create the
messages for the LED display panel. The text to be displayed is entered into the VPlayer text box.
Individual characters can be coloured Red, Green or Yellow and the display mode (static, shift left,
shift up or blink) can also be selected.
The Save Data File button creates the bitmap data file for this particular message. This processed
bitmap contains all of the individual frames required to display the entire message with the
selected effect. The bitmap file is then copied to the USB Flash drive. The master file
(SEQUENCE.TXT) on the flash drive should also be updated to add the name of the bitmap file.
This file allows multiple messages (each with their own bitmap file) to be shown in sequence and
defines the order in which they should be displayed.
The SEQUENCE.TXT file has to be manually edited using a text editor. Please refer to the section
“Updating the SEQUENCE.TXT file”.
The USB Flash drive is then inserted into the FTDI Vinco USB Host port (port 2). The firmware
reads the SEQUENCE.TXT file to determine the name of the first bitmap to display. It reads though
the bitmap, taking each frame in turn, and sending this to the display at a rate of 24 frames per
second. It then moves onto the next bitmap file in the SEQUENCE.TXT file. Once the end of the
sequence is reached, it will start at the beginning again.
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
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Clearance No.: FTDI# 277
7.1 Features supported
Text Edit box
The user enters the text in the text box.
Colour Section buttons
Select the text and click on the colour buttons to choose the text colour.
Display Mode
Select the different display modes from the list.
Save Data file
Click on the “Save Data File” button will open a File Save dialog box. Choose the folder
path, enter the filename and click on the save button. The bitmap data is stored to a
bitmap file. This bitmap file will be copied to USB Flash drive which will be connected to
the Vinco USB host port.
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Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
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Clearance No.: FTDI# 277
8 Contact Information
Head Office – Glasgow, UK
Branch Office – Hillsboro, Oregon, USA
Future Technology Devices International Limited
Unit 1, 2 Seaward Place, Centurion Business Park
Glasgow G41 1HH
United Kingdom
Tel: +44 (0) 141 429 2777
Fax: +44 (0) 141 429 2758
Future Technology Devices International Limited
(USA)
7235 NW Evergreen Parkway, Suite 600
Hillsboro, OR 97123-5803
USA
Tel: +1 (503) 547 0988
Fax: +1 (503) 547 0987
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
sales1@ftdichip.com
support1@ftdichip.com
admin1@ftdichip.com
E-Mail (Sales)
E-Mail (Support)
E-Mail (General Enquiries)
us.sales@ftdichip.com
us.support@ftdichip.com
us.admin@ftdichip.com
Branch Office – Taipei, Taiwan
Branch Office – Shanghai, China
Future Technology Devices International Limited
(Taiwan)
2F, No. 516, Sec. 1, NeiHu Road
Taipei 114
Taiwan , R.O.C.
Tel: +886 (0) 2 8791 3570
Fax: +886 (0) 2 8791 3576
Future Technology Devices International Limited
(China)
Room 408, 317 Xianxia Road,
Shanghai, 200051
China
Tel: +86 21 62351596
Fax: +86 21 62351595
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
tw.sales1@ftdichip.com
tw.support1@ftdichip.com
tw.admin1@ftdichip.com
cn.sales@ftdichip.com
cn.support@ftdichip.com
cn.admin@ftdichip.com
Web Site
http://ftdichip.com
System and equipment manufacturers and designers are responsible to ensure that their systems, and any Future Technology
Devices International Ltd (FTDI) devices incorporated in their systems, meet all applicable safety, regulatory and system-level
performance requirements. All application-related information in this document (including application descriptions, suggested
FTDI devices and other materials) is provided for reference only. While FTDI has taken care to assure it is accurate, this
information is subject to customer confirmation, and FTDI disclaims all liability for system designs and for any applications
assistance provided by FTDI. Use of FTDI devices in life support and/or safety applications is entirely at the user’s risk, and the
user agrees to defend, indemnify and hold harmless FTDI from any and all damages, claims, suits or expense resulting from
such use. This document is subject to change without notice. No freedom to use patents or other intellectual property rights is
implied by the publication of this document. Neither the whole nor any part of the information contained in, or the product
described in this document, may be adapted or reproduced in any material or electronic form without the prior written consent
of the copyright holder. Future Technology Devices International Ltd, Unit 1, 2 Seaward Place, Centurion Business Park,
Glasgow G41 1HH, United Kingdom. Scotland Registered Company Number: SC136640
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Appendix A – References
Document References
Firmware source code
http://www.ftdichip.com/Support/SoftwareExamples/VinculumIIProjects/AN_200_Source_Code.zip
[1] FTDI Application Note 142, Vinculum-II_Tool_Chain_Getting_Started_Guide, FTDI, 2010.
[2] FTDI Application Note 144, Vinculum-II_IO_Mux_Config_Utility_User_Guide, FTDI, 2010.
[3] FTDI Application Note 139, IO_MUX Explained, FTDI, 2010.
[4] FTDI Application Note 151, Vinculum-II User Guide, FTDI, 2010.
[5] FTDI Application Note 159, Vinculum-II Firmware Flash Programming, FTDI, 2011
[6] FTDI Vinco Development Module
[7] FTDI VNC2 Debug Module
Acronyms and Abbreviations
Terms
Description
GPIO
General Purpose Input / Output pin
IDE
Integrated Development Environment
IOMux
Input Output Multiplexer – Used to configure pin selection on different
package types of the VNC2.
LED
Light Emitting Diode
LED block
It consists of 8*8 dot pixel, each pixel has 1 red LED and 1 green LED
It is built with 8 LED modules in 4 * 2 array. Effectively, the LED panel
LED panel
consists of 32 (row) * 128 (column) dual LED (1 red and 1 green LED in
each pixel)
LED module
It consists of 8 LED block in a row. It has row and column control signals
designed on control PCB
SPI
Serial Peripheral Interface Bus
VNC2
Vinculum II
VOS
Vinculum Operating System
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
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9 Appendix B – LED module schematics (control board
and dot matrix board)
Figure 15 : LED control board with row drivers
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AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
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Clearance No.: FTDI# 277
Figure 16 : LED column driver
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Figure 17 : LED dot matrix with column driver for block 0 and block 1
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Figure 18 : LED dot matrix with column driver for block 2 and block 3
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Figure 19 : LED dot matrix with column driver for block 4 and block 5
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Figure 20 : LED dot matrix with column driver for block 6 and block 7
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Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Appendix C – List of Tables & Figures
List of Tables
Table 1 : Pixel colour palette .............................................................................................. 15
Table 2 : Pixel arrangement in the display buffer format for 2 blocks ....................................... 16
Table 3 : Byte arrangement in rowData Array ....................................................................... 19
List of Figures
Figure 1 : Vinco Development Module with LED dot matrix display ............................................ 3
Figure 2 : VPlayer Overview ................................................................................................. 4
Figure 3 : Vinco Development Module with VNC2 Debug Module ............................................... 7
Figure 4 : LED Display driver and multiplexing ........................................................................ 7
Figure 5 : Interfacing Vinco with LED dot matrix panel............................................................. 8
Figure 6 : VPlayer Firmware data flow ................................................................................... 9
Figure 7 : Thread Flash Disk Flow Chart ............................................................................... 12
Figure 8 : Thread displayOut Flow Chart .............................................................................. 14
Figure 9 : LED block (8x8 pixels) ........................................................................................ 15
Figure 10 : LED module Pixel numbering .............................................................................. 16
Figure 11 : LED module , data shift direction ........................................................................ 17
Figure 12 : LED Panel (32 x 64 pixels) ................................................................................. 17
Figure 13 : LED panel stacking ........................................................................................... 18
Figure 14 : VPlayer Display Software ................................................................................... 22
Figure 15 : LED control board with row drivers ..................................................................... 26
Figure 16 : LED column driver ............................................................................................ 27
Figure 17 : LED dot matrix with column driver for block 0 and block 1 ..................................... 28
Figure 18 : LED dot matrix with column driver for block 2 and block 3 ..................................... 29
Figure 19 : LED dot matrix with column driver for block 4 and block 5 ..................................... 30
Figure 20 : LED dot matrix with column driver for block 6 and block 7 ..................................... 31
32
Copyright © 2012 Future Technology Devices International Limited
Application Note
AN_200 Vinculum-II Scrolling Text Application Using LED dot matrix display
Version 1.0
Document Reference No.: FT_000571
Clearance No.: FTDI# 277
Appendix D – Revision History
Document Title:
matrix display
AN_200 Vinculum-II Scrolling Text Application Using LED dot
Document Reference No.:
FT_000632
Clearance No.:
FTDI# 277
Product Page:
http://www.ftdichip.com/Products/ICs/VNC2.htm
Document Feedback:
Send Feedback
Revision
1.0
Changes
First Release
Date
2012-02-09
33
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