AN_254 FT800 Designs with Visual TFT

Application Note
AN_254
FT800 Designs With Visual TFT
Version 1.0
Issue Date: 2013-09-30
The FTDI FT800 video controller offers a low cost solution for embedded
graphics requirements. In addition to the graphics, resistive touch inputs and
an audio output provide a complete human machine interface to the outside
world.
This application note will describe the process of developing MCU code with
MikroElektronika tools to control the FT800.
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 FTDI harmless 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 © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
Table of Contents
1
Introduction .................................................................................................................................... 2
2
VisualTFT FT800 Support................................................................................................................. 3
3
Hardware Connection ..................................................................................................................... 4
4
Visual TFT Project ............................................................................................................................ 5
4.1
Creating the project ................................................................................................................ 5
4.2
Project Settings ....................................................................................................................... 5
4.3
Placing Objects ........................................................................................................................ 7
4.4
Object Properties .................................................................................................................... 7
4.5
Generating Code ..................................................................................................................... 8
4.6
User Code ................................................................................................................................ 8
5
Code Compiler................................................................................................................................. 2
6
Code Loading onto the Microcontroller ......................................................................................... 3
7
FT800 Design Summary................................................................................................................... 4
8
MikroElektronika............................................................................................................................. 5
9
Contact Information........................................................................................................................ 6
Appendix A – References ........................................................................................................................ 7
Document References......................................................................................................................... 7
Acronyms and Abbreviations .............................................................................................................. 7
Appendix B – List of Tables & Figures ..................................................................................................... 8
List of Figures ...................................................................................................................................... 8
Appendix C – Revision History ................................................................................................................ 9
1
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
1 Introduction
The FT800 is a peripheral to the main system processor dedicated to
rendering graphics, sensing display touch stimulus, and playing audio.
The device is controlled over a low bandwidth SPI or I2C interface
allowing interfacing to nearly any microcontroller with a SPI or I2C
master port. Simple and low-pin-count microcontrollers can now have a
high-end graphical user interface by using the FT800.
After selecting the system microcontroller to be used in a design it is
important to have the correct tools to develop the firmware running on
the microcontroller.
One option is to use compilers from MikroElectronika if your chosen
microcontroller is on the list of supported devices. A key benefit in doing
this, is that MikroElectronika also provide a graphical interface tool,
Visual TFT, that integrates to their compilers.
This application note will demonstrate how the graphical interface of
Visual TFT allows users to rapidly develop a display solution by dragging
and dropping objects onto the design palette. The majority of actual code
is then created with the MikroElectronika libraries at the push of a button
to complete the design.
2
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
2 VisualTFT FT800 Support
At the time of writing, Visual TFT has FT800 library support for the following processor families:
Stellaris ARM, STM32 ARM, PIC32, ATMEGA.
It is recommended to check with MikroElectronika if a specific device is supported.
This example will use the STM32F207VG processor.
3
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
3 Hardware Connection
GPIO
TFT PANEL
FT800
RED(7:2)
SS#
SCLK
MOSI
MISO
PD#
SPI SLAVE BUS
SPI MASTER BUS
SYSTEM
MICROCONTROLLER
GREEN(7:2)
BLUE(7:2)
DE
DISP
PCLK
VSYNC
HSYNC
Figure 3.1 Interconnection Diagram
NOTE: The code being developed is running on the system microcontroller. The FT800 does not
require code compiled for it. It is simply an SPI peripheral to the system microcontroller.
4
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
4 Visual TFT Project
4.1 Creating the project
VisualTFT has a ribbon bar similar to many Microsoft applications. Selecting Project > New will
display a pop up where the project name is created and saved.
Figure 4.1 New Project
Providing a project name and selecting OK will open the Project Settings window.
4.2 Project Settings
Figure 4.2 Project Settings
The first pull down box (Hardware Patterns) on this screen allows the user to select the processor
the application code should target.
The second pull down box (Target Compiler) allows the user to select the compiler that will be
used to generate the executable binary code from the object placement performed in Visual TFT.
The advanced settings arrow expands to a form that allows the user to create processor specific
settings such as clock speed, and initialization of the interface for the SPI/I2C component of the
microcontroller.
The example given shows a clock speed of 12MHz
with an FT800 display controller connecting to a 480
x 272 display.
Figure 4.3 General Settings
5
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
The TFT tab provides a menu for setting basic display parameters. The parameters are defined
from the display datasheet.
Polarity and Clock Spread are features the FT800
supports. The polarity setting refers to data latching
on the pixel clock while clock spread determines if all
RGB signals change at the same time or are
staggered on subsequent clock edges to improve
noise immunity.
The RST and CS settings define the MCU pins that will
drive the FT800 SPI chip select input and reset pins.
Figure 4.4 TFT Settings
The Touch Panel tab allows the values for the FT800
touch registers to be set. Actual values will be
determined from the display datasheet.
For displays without touch capability the values are still
written, but have no functional meaning.
Figure 4.5 Touch Panel Settings
Resource settings are specific to the microcontroller and
define whether internal or external memory is used.
Figure 4.6 Resource Settings
When all the settings are made the user can chose to save the configuration as their own template
or simply select OK with the defaults.
It is recommended if making edits that the settings are saved with a unique name.
6
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
4.3 Placing Objects
Objects to be displayed are dragged from the component palette onto the main
window which represents the display as it will be seen in the final project.
Note the palette contains simple shapes such as lines, boxes and circles as well
as complex FT800 specific widgets for creating complex objects such as a clock,
gauge and slider bars, rapidly.
Figure 4.7 Component Palette
Figure 4.8 Objects Placement
Multiple screens are also possible by pressing the
icon.
This allows for a button press or a touch screen event to load a second screen and display new
information.
4.4 Object Properties
The properties of an object such as colour,
size and location may be configured in the
component property table. This allows for
configuration to happen without writing any
code. For complex objects, such as the clock
widget, additional settings such as the time
may be set via this property table also.
Figure 4.9 Object Properties
7
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
4.5 Generating Code
After placing the objects on the main window the next step is to generate code that the compiler
will use to generate the executable binary. With Visual TFT this is achieved with a simple button
press from the ribbon bar.
The
icon will generate the code and allow you to view the generated code.
At this stage the project contains enough information to build an output file that will configure the
microcontroller SPI port and draw a static display. To make use of the touch features or create
animations will require the user to write code.
4.6 User Code
User code allows buttons to perform functions or clocks to tick.
The first step is to create the event in the component property window.
This is the label for the actual event.
In the user code window to make the button switch from the current screen to screen2, the code
would look like:
void EveButton1OnClick() {
{DrawScreen(&Screen2);}
Figure 4.10 Object Properties
For tasks such as making the clock tick, code such as:
void Clock() {
Delay_ms(1000);
if (EveClock1.sec <= 59)
{EveClock1.sec = (EveClock1.sec + 1);
DrawScreen(&Screen2); }
else {EveClock1.sec = 0;
DrawScreen(&Screen2);
if (EveClock1.min <= 59)
{EveClock1.min = (EveClock1.min + 1);
DrawScreen(&Screen2); }
else {EveClock1.min = (EveClock1.min = 0);
DrawScreen(&Screen2);
if (EveClock1.hour <= 11)
{EveClock1.hour = (EveClock1.hour + 1);
DrawScreen(&Screen2); }
else {EveClock1.hour = (EveClock1.hour = 0);
DrawScreen(&Screen2); }
}
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Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
}
} is used.
Note the format for selecting the clock parameters:
EveClock1 is the object.
.min is the minute parameter
The value for a minute is between 0 and 59.
More information on MikroElectonica syntax is available from MikroElectronika or via the tool online
help.
This code is then sent with the full project to the compiler.
To send the code to the compiler use the
icon in the ribbon toolbar.
1
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
5 Code Compiler
The files from Visual TFT are sent to the MikroElectronika compiler. This will auto generate a
project and pull in the code created by visual TFT.
This code will all be based around MikroElectronika libraries. However the “events_code” file will
match the text input user code in Visual TFT. This code may be edited in the compiler or the visual
TFT tool as the projects are now interlinked.
From the Build option in the toolbar select “Rebuild all sources” to generate the HEX file that will
be loaded into the processor.
The tool also contains a messages window such that any errors in the code may be found. These
errors should hopefully be confined to the events_code file and not the auto generated sections.
2
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
6 Code Loading onto the Microcontroller
Loading the compiled file from the PC to the target microcontroller may depend on the
microcontroller chosen. Some devices allow for programming over UART, USB or JTAG.
At FTDI we use the mikroProg tool from MikroElectronika. This is integrated into the
MikroElectronika tool suite and allows for rapid programming and debug.
Figure 6.1 mikroProg
3
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
7 FT800 Design Summary
The FT800 provides an easy way to incorporate graphics displays into products providing for a
lower cost solution or enabling a display into systems that could not otherwise afford this
capability. With only the FT800 between the MCU and the LCD display, a vivid graphics
experience with touch and audio is now possible.
The overall design flow regardless of the toolset chosen, from component selection to displaying
the first screen is captured here:
Hardware
Select MCU
Select Display,
Audio & Touch
SPI or I2C
GPIO for PD_n
Interrupt Input
Size = WQVGA, QVGA, up to 512 x 512
Resistive Touch
Audio Amplifier
Software
Configure MCU
Interface
SPI Mode Zero -or- I2C Address
Set Host MCU SPI Speed to 10MHz maximum
Little Endian Data Format
Wake-up
FT800
Toggle PD_n low for 20ms min., then high
Write 0x00, 0x00, 0x00 to wake FT800
Write 0x44, 0x00, 0x00 to select Ext Clock
Write 0x62, 0x00, 0x00 to select 48MHz
Host MCU SPI Speed can now go up to 30MHz
REG_PCLK = zero until after display parameters are set
Configure
Display
Set Screen Registers
Vertical – REG_VCYCLE, REG_VSIZE, REG_VSYNC0/1, REG_VOFFSET
Horizontal – REG_HCYCLE, REG_HSIZE, REG_HSYNC0/1, REG_HOFFSET
Configure
Touch and
Audio
Set Touch Registers
REG_TOUCH_MODE, REG_TOUCH_RZTHRESH, Others if necessary
Set Audio Register
REG_VOL_SOUND = zero
Write Initial
Display List &
Enable Display
Write
Application
Display List
Swap Display
LIsts
CLEAR_COLOUR_RGB(0,0,0)
CLEAR(1,1,1)
DISPLAY
SWAP_LIST
REG_PWM_DUTY – brightness, PWM_HZ, frequency
REG_GPIO – bit 7 = 1 – DISP
REG_PCLK = LCD dot/pixel clock frequency
CLEAR_COLOUR_RGB(0,0,0)
CLEAR(1,1,1)
** APPLICATION DATA **
DISPLAY
SWAP_LIST
Figure 7.1 FT800 Hardware and Software Design Flow
4
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
8 MikroElektronika
MikroElektronika have been developing world class tool chains for microcontroller application
development for over a decade. To find out more about MikroElektronika and more importantly the
FT800 support they provide, visit their website at www.miikroe.com
5
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
9 Contact Information
Head Office – Glasgow, UK
Branch Office – Tigard, 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)
7130 SW Fir Loop
Tigard, OR 97223-8160
USA
Tel: +1 (503) 547 0988
Fax: +1 (503) 547 0987
E-mail (Sales)
E-mail (Support)
E-mail (General Enquiries)
[email protected]
[email protected]
[email protected]
E-Mail (Sales)
E-Mail (Support)
E-Mail (General Enquiries)
[email protected]
[email protected]
[email protected]
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 1103, No. 666 West Huaihai Road,
Shanghai, 200052
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)
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Web Site
www.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
6
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
Appendix A – References
Document References
DS_FT800 FT800 Datasheet
PG_FT800 FT800 Programmer Guide
AN_240 FT800 From the Ground Up
MikroElectronika (www.mikroe.com)
Acronyms and Abbreviations
Terms
Description
EVE
Embedded Video Engine
GPIO
General Purpose Input / Output
I2C
Inter-Integrated Circuit
IC
Integrated Circuit
MCU
Microcontroller
QVGA
Quarter VGA (320 x 240 pixel display size)
SPI
Serial Peripheral Interface
TFT
Thin-Film Transistor
VGA
Video Graphics Array
WQVGA
Wide Quarter VGA (480 x 272 pixel display size)
7
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
Appendix B – List of Tables & Figures
List of Figures
Figure 3.1 Interconnection Diagram ...................................................................................... 4
Figure 4.1 New Project ........................................................................................................ 5
Figure 4.2 Project Settings ................................................................................................... 5
Figure 4.3 General Settings .................................................................................................. 5
Figure 4.4 TFT Settings ........................................................................................................ 6
Figure 4.5 Touch Panel Settings ............................................................................................ 6
Figure 4.6 Resource Settings ................................................................................................ 6
Figure 4.7 Component Palette............................................................................................... 7
Figure 4.8 Objects Placement ............................................................................................... 7
Figure 4.9 Object Properties ................................................................................................. 7
Figure 4.10 Object Properties ............................................................................................... 8
Figure 6.1 mikroProg ........................................................................................................... 3
Figure 7.1 FT800 Hardware and Software Design Flow ............................................................. 4
8
Copyright © 2013 Future Technology Devices International Limited
Application Note
AN_254 FT800 Designs With Visual TFT
Version 1.0
Document Reference No.: FT_000880
Clearance No.: FTDI# 350
Appendix C – Revision History
Document Title:
AN_254 FT800 Designs With Visual TFT
Document Reference No.:
FT_000880
Clearance No.:
FTDI# 350
Product Page:
http://www.ftdichip.com/EVE.htm
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Revision
Changes
Date
1.0
Initial Release
2013-09-30
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Copyright © 2013 Future Technology Devices International Limited
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