FDI UEZGUI-1788-56VI Instruction Manual

www.TeamFDI.com
Rev. 1.11 Aug 31, 2016 Page 1
FDI_AN_µEZ_009
µEZ GUI Start Here Guide
UEZGUI-1788-56VI
Introduction
At Future Designs, our goal is to make it easy for our customers to get their projects up and running as
quickly as possible. In this guide, you will develop a simple graphical user interface (GUI) on the µEZ
platform to demonstrate how to use some of the core features of emWin and µEZ. Using this “Hello
World” type of walkthrough as a starting point, we hope to shorten the learning curve for GUI
development. Aside from this document, there are many additional resources available at
www.TeamFDI.com. If you ever need more help, contact us and we will be happy to assist you.
Hardware Used in This Guide: (Included in Kit)
UEZGUI-1788-56VI-BA
SEGGER J-Link Lite Probe
FDI J-Link 20-pin to mini-10 pin adapter model JLINK-ARM-AD
USB Type A to USB Type Mini B Cable (2x)
Universal AC to 5V USB plug Power Supply Unit
Software Used in This Guide:
(Installation and usage instructions are provided within the guide)
SEGGER J-Link Software
µEZ Source w/ Project Maker (v2.08 or later)
One of the following IDEs:
oRowley CrossWorks v3.6.5
oIAR Embedded Workbench v7.60
Files Used in This Guide:
(Installation and usage instructions are provided within the guide)
Start Here Project Files (located in the µEZ source download)

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Contents
1. Hardware Verification............................................................................3
2. Software Installation..............................................................................4
A. IDE Installation .................................................................................................................. 4
B. J-Link Installation............................................................................................................... 4
C. µEZ Installation.................................................................................................................. 4
3. Connecting the J-Link Debugger to the µEZ GUI for programming ..........5
4. Developing a Simple GUI Application with emWin .................................5
A. emWin Introduction.......................................................................................................... 5
B. Building and Running the Initial Project............................................................................ 6
C. Adding a Button to the Home Screen .............................................................................11
D. Creating a New Window .................................................................................................15
E. Adding Callback Functionality ......................................................................................... 19
F. Interfacing with the Onboard Temperature Sensor .......................................................20
G. Creating a Task................................................................................................................ 22
H. Adding a Back Button......................................................................................................24
5. Restoring the Out-of-Box (OOB) Demo (Optional) ................................27
6. Next Steps............................................................................................28
7. Website and Support............................................................................28
Important Legal Information
Information in this document is provided solely to enable the use of Future Designs products. FDI assumes no
liability whatsoever, including infringement of any patent or copyright. FDI reserves the right to make
changes to these specifications at any time, without notice. No part of this document may be reproduced or
transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express
written permission of Future Designs, Inc. (FDI) 996 A Cleaner Way, Huntsville, AL 35805.
For more information on FDI or our products please visit www.teamfdi.com.
NOTE: The inclusion of vendor software products in this kit does not imply an endorsement.
© 2016 Future Designs, Inc. All rights reserved.
µEZ® is a registered trademark of Future Designs, Inc. Windows is a registered trademarks of Microsoft.
emWin and J-Link are registered trademarks of SEGGER Microcontroller GmbH & Co. KG. IAR EMBEDDED
WORKBENCH is a registered trademark of I.A.R. Systems AB.

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1. Hardware Verification
The µEZ GUI kit comes with a pre-installed 4GB or larger SD card that contains files
required for the demo application and slideshow to run. It also contains user manuals,
schematics, and documentation for the product including this guide. FDI recommends
that you visit the documentation tab of the product page of your µEZ GUI to get the
latest documentation.
Power is supplied via the USB power adapter and cable provided in the kit.
1. Connect the USB cable to the mini USB Type B connector (P2) on the µEZ GUI.
2. Connect the other end of the USB cable to the provided universal AC power
supply’s 5V USB power output.
NOTE: The µEZ GUI must be powered with the included universal AC to 5V USB plug
power supply or through the alternate power and com port on the side. Do not try to
power the µEZ GUI from a computer’s USB port. The standard PC USB port does not
provide the necessary current to power the µEZ GUI. The JTAG port and J-Link probe do
not power the µEZ GUI.
The following screen will appear once power has been connected to the device:
You can now explore the out-of-box demos. Test the GUI by selecting “Draw” and
drawing lines on the screen with your finger.
Figure 1:
UEZGUI-
1788-56VI
Figure 2:
Out-of-Box
(OOB)
Demo

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2. Software Installation
A. IDE Installation
All µEZ GUI projects require a development environment to compile and debug the projects.
µEZ currently officially supports IAR Embedded Workbench v7.60 and Rowley CrossWorks
3.6.5 on the LPC1788. This guide uses IAR Embedded Workbench for ARM version 7.60 and
Rowley Crossworks for ARM Version 3.6.5. Download your preferred IDE at the appropriate
link provided below and install according to the instructions provided on their respective
websites.
IAR Embedded Workbench 7.60 30-day free trial: (select Evaluation License option on install)
Windows: http://tinyurl.com/glljfsj
oIAR 30-day evaluation license manual activation instructions: http://tinyurl.com/zyctkha
Rowley CrossWorks for ARM version 3.6.5 30-day free trial:
Windows: http://tinyurl.com/z2wgnsk
Mac: http://tinyurl.com/he4tgtu
Linux x86: http://tinyurl.com/zzcu5ny
Linux ARMV7: http://tinyurl.com/hvzpq8e
oActivating Crossworks 30-day evaluation license instructions: http://tinyurl.com/hlsn9qf
B. J-Link Installation
The µEZ GUI uses a J-Link debugger probe. The SEGGER version 5.12J driver must be installed.
Download and install the software from the link below:
SEGGER J-Link Software 5.12j:
Windows: http://tinyurl.com/jr6s6xl
Mac: http://tinyurl.com/zshoj6r
Linux x86: http://tinyurl.com/jdkzsx9
Linux ARMV7: http://tinyurl.com/zat25fs
C. µEZ Installation
µEZ is a middleware API library built on FreeRTOS and emWin. It is created, managed and
regularly updated by FDI. Download the latest µEZ release at the link provided below:
EZ (v2.08): https://sourceforge.net/projects/uez/
Extract the µEZ 7z, or zip file, to the desired location. This folder contains the µEZ source
library, helpful tools, documentation, project files referenced in this guide, and the µEZ
project maker. The library files will be compiled in subsequent steps.

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3. Connecting the J-Link Debugger to the µEZ GUI for programming
1. Connect the J-Link probe to a PC with an included USB cable.
2. Connect the J-Link probe to the FDI mini-10 pin JTAG connector (J5) on the bottom
side of the µEZ GUI. The J-Link ribbon cable and FDI adapter for the µEZ GUI are
supplied in the kit. The 10-pin connector can only be connected one way.
3. If not already done, connect the µEZ GUI to the power supply with the second
included USB cable.
4. Developing a Simple GUI Application with emWin
A. emWin Introduction
emWin (segger.com/emwin.html) is a software library from SEGGER which provides an
efficient GUI library that is processor and LCD controller independent. emWin enables
Figure 3:
J-Link
Hardware
Figure 4:
J-Link
Connected
to µEZ GUI

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you to easily add graphics to an application and is included with µEZ. Some of the
features of emWin include:
Basic drawing functions such as drawing lines, squares, circles and polygons.
More complex functions such as managing windows, button widgets, list-view
widgets, edit widgets, etc.
Displaying images.
Support for multiple displays.
Support for multiple layers and transparency settings.
Control of GUI by mouse and touch screen.
Rapid development, even without targeted hardware, due to support for simulating
the GUI in Microsoft Visual Studio.
NXP® Semiconductors has a license with SEGGER that allows any device using an NXP
LPC microcontroller to use the full emWin library without requiring an additional
license. Since the UEZGUI-1788-56VI-BA utilizes the LPC1788, the emWin license applies.
See here for more information: http://tinyurl.com/gueckmp, NXP emWin introduction
video: http://tinyurl.com/jrata57
This section of the guide will take a simple screen and develop it into a GUI to
demonstrate a few of the core features of the µEZ and emWin libraries.
B. Building and Running the Initial Project
Before digging into the code of the project, examine the output by building and running
the initial project as outlined in the steps below:
NOTE: The following sections reference the uEZ files from Sourceforge. In the following
instructions, the “uEZ_v2.XX_SourceForge” files were unpackaged to the C:\Workspace
folder on a Windows PC.
1. Navigate to the extracted folder from the µEZ download. The beginning project for
the Start Here Guide is located in the µEZ download in the
uEZ_v2.XX_SourceForge/StartHere folder. The finished project is also included in the
uEZ_v2.XX_SourceForge/StartHereEnd folder for you to reference as needed.
Figure 5:
µEZ files from
SourceForge
Download
(v2.08 shown)

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2. Locate the “uEZ” folder within the EZ download. This folder includes the µEZ
library files needed by the project to function. The uEZ folder must always be in the
same directory as the project’s main folder, like it is in the download. Otherwise,
EZ projects would not be able to get the library files they need to compile.
3. Navigate through the uEZ folder to uEZ_v2.XX_SourceForge/uEZ/Build/Generic/NXP.
Then, locate the folder corresponding to the microcontroller used in the EZ GUI.
NOTE: The processor number is the first set of numbers in the model number of the
µEZ GUI. This UEZGUI-1788-56VI uses an LPC1788 micro-controller and the
corresponding folder referenced in this step is labeled accordingly.
4. Navigate to FreeRTOS\IAR\ or FreeRTOS\Crossworks\ and open the IAR
(uEZ_NXP_LPC1788_FreeRTOS_IAR.eww) or Crossworks
(uEZ_NXP_LPC1788_FreeRTOS_CrossWorks.hzp) workspace/project file. If you have
multiple versions of IAR or Crossworks installed, make sure that these projects are
opened in the correct installation of the respective IDE.
NOTE: Note: Both IAR and Crossworks are shown in this guide, but only one should be
used when following this guide. The same version of the IDE must be used both for
building the library and final µEZ GUI executable.
The project should now open up in the IDE.
Figure 6:
Navigating
to the µEZ
Workspace
Figure 7:
Opening
the µEZ
Workspace

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5. After the project opens:
For IAR: Select the “Debug” Build from the workspace menu if not already selected.
For Crossworks: Select the “Project Explorer” sub-window if not already selected.
6. Next building the project:
For IAR: Select “Project > Make” or press F7 to build the µEZ library project.
For Crossworks: Select “Build->Build…” or press F7 to build the µEZ library project.
IAR
Crossworks
7. After the build process is complete, there should be no errors.
IAR
Crossworks
8. Close the IDE.
Figure 8:
Building the
µEZ library
project
Figure 9:
Build
Finished

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9. Next open up the actual start here project by navigating to the appropriate location:
For IAR the workspace file is at
StartHere\Build\uEZGUI_1788_56VI\IAR\uEZGUI_StartHere.eww.
For Crossworks the project file is at
StartHere\Build\uEZGUI_1788_56VI\Crossworks\uEZGUI_StartHere.hzp.
10. Verify that the Debug build is selected to match the library project.
11. If using IAR, proceed to step 12, otherwise proceed to step 15.
12. Right click the main project name in the workspace and select “Options”
13. Select “Debugger” and verify that the “Driver” is set to “J-Link/J-Trace”.
Figure 11:
Debug
Settings
Figure 10:
Start Here
Project
Locations

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14. Click the [OK] button to exit the dialog. Proceed to step 17
15. If using Crossworks, proceed to step 16, otherwise proceed to step 17.
16. Click “Target > Connect > SEGGER J-Link” from the drop down menu. This activates
the J-Link probe.
17. Build (if needed), download and run the project following the respective IDE steps.
For IAR: Press [Ctrl]+[D] or select “Project > Download and Debug” from the menu
at the top.
For Crossworks: Press [F5] or select “Debug > Go” from the menu at the top.
18. If the debugger has halted on a breakpoint, press [F5] to make the project run.
After the project is running on the µEZ GUI, a simple window is shown with three text
bars.
Figure 14:
Initial
project
Figure 12:
Debug
Settings
Figure 13:
Debug
Settings

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To see where the window is developed, examine the folder structure of the initial
project.
All of the source code used to provide functionality to the project is within the
“Source\App” directory. The “Source\App\emWin” directory contains the code that
uses emWin to create and manage windows and other graphic designs for the GUI.
C. Adding a Button to the Home Screen
To demonstrate the process for adding widgets to a window, this section will walk you
through the steps to create a button on the home screen which, once pressed, will open
to a new window. To begin, open the HomeScreen.c file in the emWin directory.
The HomeScreen.c file contains the information that is used to create a window and any
widgets (buttons, etc) that will load with the window. The beginning of the file contains
the #includes and a list of definitions that define the ID, size, and position of each object
within the window including the window itself.
In the next section, “Local Data”, there are two array variables which define the window
and widgets and associate callback functions to them. The first array,
_iHomeScreenDialog[ ], is an emWin array that holds the ID, position, and size for each
widget. The second array, HomeScreenMapping[ ] is a µEZ array which holds their text
label, color, font, and callback functions.
NOTE: A callback function is a function which is called when an associated event occurs.
For buttons, this event is a touch event. When the button is pressed (or depressed), the
callback function is run to perform the desired task.
Figure 15:
File
Hierarchy

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The remainder of the file contains the emWin event handler function and a window
setup function. Any callback function that is used for widgets will also be placed in this
section.
NOTE: Most of the code segments in this guide are formatted to be copied and pasted
to assist you in easily applying the code to your project.
1. The “Start Here” text can be replaced with a button by modifying the existing code.
The definitions associated with the “Start Here” text are shown below:
NOTE: Each widget, including the window itself, has a unique ID defined as shown
above. Each additional widget increments by 1 and adding a new ID for an additional
widget is as simple as setting it to the next value. GUI_ID_USER is equal to 0x800 by
default and needs to be used to avoid conflicts with other areas of the program.
/*---------------------------------------------------------------------------*
* Constants:
*--------------------------------------------------------------------------*/
#define ID_WINDOW (GUI_ID_USER + 0x00)
#define ID_TITLE_TEXT (GUI_ID_USER + 0x01)
#define ID_STARTHERE_TEXT (GUI_ID_USER + 0x02)
#define ID_FDIINFO_TEXT (GUI_ID_USER + 0x03)
#define WINDOW_XSIZE (UEZ_LCD_DISPLAY_WIDTH)
#define WINDOW_YSIZE (UEZ_LCD_DISPLAY_HEIGHT)
#define WINDOW_XPOS (0)
#define WINDOW_YPOS (0)
#if(UEZ_DEFAULT_LCD == LCD_RES_WVGA)
#define SPACING (10)
#define FONTSIZE &FONT_LARGE
#else
#define SPACING (5)
#define FONTSIZE &FONT_SMALL
#endif
#define TITLE_TEXT_XSIZE (WINDOW_XSIZE)
#define TITLE_TEXT_YSIZE ((WINDOW_YSIZE/10))
#define TITLE_TEXT_XPOS (0)
#define TITLE_TEXT_YPOS (0)
#define STARTHERE_TEXT_XSIZE (WINDOW_XSIZE)
#define STARTHERE_TEXT_YSIZE ((WINDOW_YSIZE/10))
#define STARTHERE_TEXT_XPOS (0)
#define STARTHERE_TEXT_YPOS ((WINDOW_YSIZE/10)*4 + 10)

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2. Replace the definitions with the names and values associated with the new button
being created:
/*---------------------------------------------------------------------------*
* Constants:
*--------------------------------------------------------------------------*/
#define ID_WINDOW (GUI_ID_USER + 0x00)
#define ID_TITLE_TEXT (GUI_ID_USER + 0x01)
#define ID_MYBUTTON_BUTTON (GUI_ID_USER + 0x02)
#define ID_FDIINFO_TEXT (GUI_ID_USER + 0x03)
#define WINDOW_XSIZE (UEZ_LCD_DISPLAY_WIDTH)
#define WINDOW_YSIZE (UEZ_LCD_DISPLAY_HEIGHT)
#define WINDOW_XPOS (0)
#define WINDOW_YPOS (0)
#if(UEZ_DEFAULT_LCD == LCD_RES_WVGA)
#define SPACING (10)
#define FONTSIZE &FONT_LARGE
#else
#define SPACING (5)
#define FONTSIZE &FONT_SMALL
#endif
#define TITLE_TEXT_XSIZE (WINDOW_XSIZE)
#define TITLE_TEXT_YSIZE ((WINDOW_YSIZE/10))
#define TITLE_TEXT_XPOS (0)
#define TITLE_TEXT_YPOS (0)
#define FDIINFO_TEXT_XSIZE (WINDOW_XSIZE)
#define FDIINFO_TEXT_YSIZE ((WINDOW_YSIZE/10))
#define FDIINFO_TEXT_XPOS (0)
#define FDIINFO_TEXT_YPOS ((WINDOW_YSIZE/10)*9 + 0)
#define MYBUTTON_BUTTON_XSIZE (WINDOW_XSIZE/3 + 20)
#define MYBUTTON_BUTTON_YSIZE ((WINDOW_YSIZE/5))
#define MYBUTTON_BUTTON_XPOS (WINDOW_XSIZE/3 - 10)
#define MYBUTTON_BUTTON_YPOS ((WINDOW_YSIZE/10)*4)

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3. The two arrays under the section header “Local Data” still contain the information
from the “Start Here” text. Each widget is represented in one of the sections within
each array. Identify where the “Start Here” text is.
4. Replace the “Start Here” text field’s information with the following button
information:
/*---------------------------------------------------------------------------*
* Local Data:
*---------------------------------------------------------------------------
*/
/** Structure to hold all of the widgets used in this dialog*/
static const GUI_WIDGET_CREATE_INFO _iHomeScreenDialog[] ={
//Function, Name, ID, XP, YP, XS, YS
{WINDOW_CreateIndirect,"",ID_WINDOW,WINDOW_XPOS,WINDOW_YPOS,
WINDOW_XSIZE,WINDOW_YSIZE,0,0,0},
{TEXT_CreateIndirect,"",ID_TITLE_TEXT,TITLE_TEXT_XPOS,
TITLE_TEXT_YPOS,TITLE_TEXT_XSIZE,TITLE_TEXT_YSIZE,
TEXT_CF_HCENTER|TEXT_CF_VCENTER,0, 0},
{TEXT_CreateIndirect,"",ID_STARTHERE_TEXT,STARTHERE_TEXT_XPOS,
STARTHERE_TEXT_YPOS,STARTHERE_TEXT_XSIZE,STARTHERE_TEXT_YSIZE,
TEXT_CF_HCENTER|TEXT_CF_VCENTER,0,0},
{TEXT_CreateIndirect,"",ID_FDIINFO_TEXT,FDIINFO_TEXT_XPOS,
FDIINFO_TEXT_YPOS,FDIINFO_TEXT_XSIZE,FDIINFO_TEXT_YSIZE,
TEXT_CF_HCENTER|TEXT_CF_VCENTER,0,0},
};
/** Generic Mapping of Screen Layout*/
static T_LAFMapping HomeScreenMapping[] ={
{ID_WINDOW,"",GUI_BLACK,GUI_WHITE,&FONT_SMALL,LAFSetupWindow,0},
{ID_TITLE_TEXT,"Welcome To uEZ GUI!",GUI_BLACK,GUI_WHITE,&FONT_LARGE,
LAFSetupText,0},
{ID_STARTHERE_TEXT,"\"START HERE\"",GUI_BLACK,GUI_WHITE,&FONT_LARGE,
LAFSetupText,0},
{ID_FDIINFO_TEXT,
"Future Designs, Inc. 2016 www.TeamFDI.com",
GUI_BLACK,GUI_WHITE,FONTSIZE,LAFSetupText,0},
{0},
};
/*---------------------------------------------------------------------------*
* Local Data:
*---------------------------------------------------------------------------
*/
/** Structure to hold all of the widgets used in this dialog*/
static const GUI_WIDGET_CREATE_INFO _iHomeScreenDialog[] ={
//Function, Name, ID, XP, YP, XS, YS
{WINDOW_CreateIndirect,"",ID_WINDOW,WINDOW_XPOS,WINDOW_YPOS,
WINDOW_XSIZE,WINDOW_YSIZE,0,0,0},
{TEXT_CreateIndirect,"",ID_TITLE_TEXT,TITLE_TEXT_XPOS,
TITLE_TEXT_YPOS,TITLE_TEXT_XSIZE,TITLE_TEXT_YSIZE,
TEXT_CF_HCENTER|TEXT_CF_VCENTER,0,
0},
{BUTTON_CreateIndirect,"",ID_MYBUTTON_BUTTON,MYBUTTON_BUTTON_XPOS,
MYBUTTON_BUTTON_YPOS,MYBUTTON_BUTTON_XSIZE,MYBUTTON_BUTTON_YSIZE,
TEXT_CF_HCENTER|TEXT_CF_VCENTER,0,0},
{TEXT_CreateIndirect,"",ID_FDIINFO_TEXT,FDIINFO_TEXT_XPOS,
FDIINFO_TEXT_YPOS,FDIINFO_TEXT_XSIZE,FDIINFO_TEXT_YSIZE,
TEXT_CF_HCENTER|TEXT_CF_VCENTER,0,0},
};

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5. Build, download, debug, and run the updated project to display the created button.
For IAR: Press [Ctrl]+[D].
For Crossworks: Press [F5].
The button does not do anything yet because it lacks a callback function, but this
will be added later once a second window has been created for the button to switch
to.
D. Creating a New Window
In order to have the button open a new window, a new window file similar to the
HomeScreen.c file needs to be created. Since each window requires the same general
structure, copy the existing HomeScreen.c file, instead of creating a new file from
scratch.
1. Right click the HomeScreen.c file
For IAR: Select “Open Containing Folder…”.
For Crossworks: Select “Select in File Explorer”.
2. Copy the HomeScreen.c file located in the emWin directory and rename it
SecondScreen.c.
3. Back in the IDE, right click the emWin folder.
For IAR: Select “Add > Add Files…”.
For Crossworks: Select “Add Existing File...”.
4. In the browse files dialog that appears, select SecondScreen.c and click Open.
5. Open the new file by double clicking it in the IDE workspace or project explorer.
6. Rename all instances of “HomeScreen” to “SecondScreen” (only in that file).
/** Generic Mapping of Screen Layout*/
static T_LAFMapping HomeScreenMapping[] ={
{ID_WINDOW,"",GUI_BLACK,GUI_WHITE,&FONT_SMALL,LAFSetupWindow,0},
{ID_TITLE_TEXT,"My Main Screen",GUI_BLACK,GUI_WHITE,&FONT_LARGE,
LAFSetupText,0},
{ID_MYBUTTON_BUTTON,"Temperature",GUI_GRAY,GUI_BLACK,&FONT_LARGE,
LAFSetupButton,0},
{ID_FDIINFO_TEXT,
"Future Designs, Inc. 2016 www.TeamFDI.com",
GUI_BLACK,GUI_WHITE,FONTSIZE,LAFSetupText,0},
{0},
};
Figure 16:
Button
Added

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NOTE: To simplify this process, just press Ctrl+H to open the Find and Replace dialog.
Insert “HomeScreen” in the Find what field and “SecondScreen” in the Replace with
field. Select Match case and make sure Match whole word is unselected. Click Replace
All and the entire document will be updated.
7. Delete all the widget definitions that were specific to the home screen.

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8. The two arrays that hold the information for the various widgets on a window are
shown below. Delete the lines highlighted in red that are specific to the first
window. The only remaining values within each of these array variables define the
window’s properties and title text that will be used by emWin to setup the window.

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9. This file now contains the minimum required information to setup a blank window.
The final step to creating the window is to update the WindowManager.c file. Open
the file and update the WindowManager_Create_All_Active _Windows function as
shown below:
You also need to add a #define identifier for SECOND_SCREEN to the top of the
WindowManager.h file as shown below if not already present:

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E. Adding Callback Functionality
Now that the second screen has been created, return to HomeScreen.c and add a
callback function to the previously created button. Once this callback function is
created, the button will switch to the newly created second window when it is pressed.
1. Add the name of the callback function into the first widget definition matrix. (the
“Temperature” button) You can choose any name to give the callback function. In
this example we used
(TBool (*)(WM_MESSAGE *, TInt32, TInt32)) IHandleSecondScreen to make the
function name easily understandable.
2. Declare the callback function’s prototype between the “Global Data” and “Local
Data” sections of the HomeScreen.c file. In addition add the “G_WhichWindow”
variable in the “Global Data” section.
3. Create the callback function below the “Local Data” section. This function takes a
message from the event handler and switches windows when the button is pressed.
/*---------------------------------------------------------------------------*
* Global Data:
*--------------------------------------------------------------------------*/
static TBool G_Active =EFalse;// Active Flag, tell the dialog when it
receives messages that the screen is in the foreground
TInt32 G_WhichWindow; // Variable to hold the ID of the active window
/*-------------------------------------------------------------------------*
* Function Prototypes:
*-------------------------------------------------------------------------*/
static TBool IHandleSecondScreen(WM_MESSAGE *pMsg,int aNCode,int aID);
/*---------------------------------------------------------------------------*
* Local Data:
*--------------------------------------------------------------------------*/

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4. Use the appropriate steps to Build, download, debug, and run the updated project
to test the functionality. Since the second window is blank, pressing the button will
display a black screen.
F. Interfacing with the Onboard Temperature Sensor
In the following steps of this guide we will demonstrate how to interface with the uEZ
GUI hardware using the on-board temperature sensor and how to update the
temperature on the screen. We will start by returning to the SecondScreen.c file in the
IDE, then creating two new text fields. One text field will be a title for the temperature
reading, and the other will show the onboard temperature sensor value. Finally, we will
add a back button to return to the home screen.
1. First, open SecondScreen.c to add the new text fields and give the temperature text
an update function.
2. Define a new ID for the Temperature Text.
3. Define the temperature fields’position and size.
NOTE: We use WINDOW_XSIZE and WINDOW_YSIZE to size and place all GUI elements
relative to the screen, so it is easy to change to a different LCD screen resolution
without need to re-write the element placement code.
/*-------------------------------------------------------------------------*
* Routine: IHandleSecondScreen
*-------------------------------------------------------------------------*
* Description:
* Change to the second screen when the temperature button is pressed.
*-------------------------------------------------------------------------*/
static TBool IHandleSecondScreen(WM_MESSAGE *pMsg,int aNCode,int aID)
{
if (aNCode == WM_NOTIFICATION_RELEASED){
WindowManager_Show_Window(SECOND_SCREEN);
}
return EFalse;
}
#define ID_WINDOW (GUI_ID_USER + 0x00)
#define ID_TITLE_TEXT (GUI_ID_USER + 0x01)
#define ID_TEMP_TEXT (GUI_ID_USER + 0x02)
#define TITLE_TEXT_XSIZE (WINDOW_XSIZE)
#define TITLE_TEXT_YSIZE ((WINDOW_YSIZE/10))
#define TITLE_TEXT_XPOS (0)
#define TITLE_TEXT_YPOS (0)
#define TEMP_TEXT_XSIZE (WINDOW_XSIZE/3)
#define TEMP_TEXT_YSIZE ((WINDOW_YSIZE/5))
#define TEMP_TEXT_XPOS (WINDOW_XSIZE/3)
#define TEMP_TEXT_YPOS ((WINDOW_YSIZE/10)*4)