Platform Integration: Getting started with Raspberry Pi

Raspberry Pi with 7" touch screen.

The following article explains all necessary steps to create an Embedded Wizard UI application suitable for the Raspberry Pi 2B / 3B with Raspberry Pi Touch Display. Please follow these instructions carefully and step by step in order to ensure that you will get everything up and running on your target. Moreover, this article assumes, that you are familiar with the basic concepts of Embedded Wizard.

Prerequisites

First of all, you need the following hardware components:

Raspberry Pi 2 Model B or Raspberry Pi 3 Model B

Raspberry Pi Touch Display 7"

Suitable power supply for your Raspberry Pi board and display

Network cable to connect the Raspberry Pi board with your network

Micro SD card with 8GB

Make sure that you have got the following software packages:

Embedded Wizard Studio Free or Embedded Wizard Studio Pro

Embedded Wizard Raspberry Pi Platform Package

Embedded Wizard Build Environment for Raspberry Pi

TIP

If you want to use the Free edition of Embedded Wizard Studio and the Raspberry Pi Platform Package, please register on our website and select the target Raspberry Pi. Then you can download the above software packages.

All customers who licensed Embedded Wizard can visit our download center to get the above software packages.

Installing Tools and Software

Step 1: Install the latest version of Embedded Wizard Studio.

Step 2: Install the Embedded Wizard Raspberry Pi Platform Package.

Step 3: Unpack the provided Embedded Wizard Build Environment for Raspberry Pi into a new directory, e.g. {UserDocumentFolder}\RaspberryPi.

Step 4: Download the latest version of the Raspbian Stretch Lite image and write the image to your SD card (please have a look to the Raspberry Pi installation guide for more details).

Exploring the Build Environment

The provided Embedded Wizard Build Environment for Raspberry Pi contains everything you need to create, compile and link an Embedded Wizard UI application for the Raspberry Pi target. After unpacking, you will find the following subdirectories and files:

\Application - This folder contains a ready-to-use project to compile and link an Embedded Wizard generated UI application. It is used for all provided examples and it can be used to build your own UI applications.

\GeneratedCode - This folder is used to receive the generated code from an Embedded Wizard UI project. The template project is building the UI application out of this folder. You can create your own UI project and generate the code into the subdirectory \GeneratedCode without the need to adapt the project.

\Project - This folder contains the prepared project for GCC (make).

\Source - This folder contains the files main.c and ewmain.c. There you will find the initialization of the system and the main loop to drive an Embedded Wizard GUI application. Additionally, this folder contains the device driver C/H files used for the DeviceIntegration example.

\Build - This folder contains makefile configurations, necessary to build your UI application by using the make utility.

\Examples - This folder contains a set of demo applications. Each example is stored in a separate folder containing the entire Embedded Wizard UI project. Every project contains the necessary profile settings for the Raspberry Pi target. The following samples are provided:

\HelloWorld - A very simple project that is useful as starting point and to verify that the entire toolchain, your installation and your board is properly working.

\GraphicsOperations - This application demonstrates the graphics performance of the target by using sets of basic drawing operations that are executed permanently and continuously.

\BrickGame - The sample application BrickGame implements a classic "paddle and ball" game. In the game, a couple of brick rows are arranged in the upper part of the screen. A ball travels across the screen, bouncing off the top and side walls of the screen. When a brick is hit, the ball bounces away and the brick is destroyed. The player has a movable paddle to bounce the ball upward, keeping it in play.

\ChartsDemo - This application demonstrates the possibilities and the usage of the chart classes LineChart, BarChart and PieChart. The appearance of each chart diagram can be configured easily by using their corresponding properties. Additionally, this demo shows the usage of an outline box to manage scrollable content.

\ClimateCabinet - The ClimateCabinet demo shows the implementation of a control panel for a climatic exposure test cabinent. The user can define a heating time, a nominal temperature and humidity, a dwell time and the final cooling time.

\DeviceIntegration - This example shows the integration of devices into a UI application and addresses typical questions: How to start a certain action on the target? How to get data from a device?

\PaperCutter - This demo shows the implementation of a paper cutting machine, where the user can define the pagination and format of the paper as well as the cutting speed and the amount of papers. The application contains many rect effects and fade-in/fade-out effects to change dynamically the layout of the screen.

\WashingMachine - This demo shows the implementation of a washing machine with a couple of fancy scrollable list widgets to choose the washing program and parameters. The speciality of this sample application is the magnification effect of the centered list items and the soft fade-in/fade-out effects.

\WaveformGenerator - This WaveformGenerator demo application combines waveforms with different amplitudes and frequencies. The implementation shows the usage of the class Charts::Graph to paint a list of coordinates.

\PlatformPackage - This folder contains the necessary source codes and/or libraries of the Raspberry Pi Platform Package: The Graphics Engine (in the subdirectory \RGBA8888) and the Runtime Environment (in the subdirectory \RTE).

\TargetSpecific - This folder contains all configuration files and platform specific source codes. The different ew_bsp_xxx files implement the bridge between the Embedded Wizard UI application and the underlying Raspberry Pi hardware drivers in order to access the display (via EGL), the serial interface and the touch driver.

Preparing the PC

Share your new Build Environment folder {UserDocumentFolder}\RaspberryPi as RaspberryPi and allow read/write access for everybody.

Get the IP address of your PC - for example by using the command ipconfig within the Windows command line and note it (e.g. 192.168.0.xxx).

Preparing the Raspberry Pi

Connect the display with the Raspberry Pi board.

Connect a standard USB keyboard at the Raspberry Pi board.

Insert the SD card and power on the system.

Login as pi with password raspberry.

Start the Raspberry Pi configuration tool (via sudo raspi-config) and enable SSH.

Shutdown the board via sudo halt and power off.

Disconnect the USB keyboard, connect the Raspberry Pi board to your network router and power on the system.

When the boot procedure of the Raspberry Pi is completed you can read the IP address of the Raspberry Pi on the display: e.g. My IP address is 192.168.0.yyy.

Mounting the Project Directory

Open a SSH client (e.g. 'Putty') on your PC and connect to the Raspberry Pi by using the IP address of the Raspberry Pi (e.g. 192.168.0.yyy).

Login as pi with password raspberry.

Create a new directory share on your Raspberry Pi:

Mount the Build Environment folder of your PC to this new share directory. Please use the IP address of your PC and your login name on the PC. In order to get access to your shared directory, you need to insert your PC login password.

Change into the new directory share on your Raspberry Pi and check if you see the content of the mounted PC folder. As a result you should see the content of the Raspberry Pi Build Environment:

Creating the UI Examples

For the first bring up of your system, we recommend to use the example 'HelloWorld':

Example 'HelloWorld' within Embedded Wizard Studio.

The following steps are necessary to generate the source code of this sample application:

On your PC, navigate to the directory \Example\HelloWorld.

Open the project file HelloWorld.ewp with your previously installed Embedded Wizard Studio. The entire project is well documented inline. You can run the UI application within the Prototyper by pressing Ctrl+F5.

To start the code generator, select the menu items BuildBuild this profile - or simply press F8. Embedded Wizard Studio generates now the sources files of the example project into the directory \Application\GeneratedCode.

Compiling, Linking and Executing

The following steps are necessary to build and execute the Embedded Wizard UI sample application on the Raspberry Pi. Please note, that the entire project is build directly on your Raspberry Pi target, without using a cross compiler.

The SSH client should be still opened, the directory \share is the current directory.

Navigate to the subdirectory \Application and make the binary:

Finally, the application can be executed on the Raspberry Pi:

This is the resulting application on your Raspberry Pi target:

Example 'HelloWorld' running on Raspberry Pi board.

The application can be terminated by pressing P.

All other examples can be created in the same way: Just open the desired example with Embedded Wizard Studio, generate code and rebuild the whole application.

Creating your own UI Applications

In order to create your own UI project suitable for the Raspberry Pi target, you can create a new project and select the Raspberry Pi project template:

As a result you get a new Embedded Wizard project, that contains the necessary Profile attributes suitable for the Raspberry Pi board:

The following profile settings are important for your target:

The attribute PlatformPackage should refer to the installed Raspberry Pi Platform Package.

The attribute ScreenSize should correspond to the display size of the Raspberry Pi touch screen.

The attribute OutputDirectory should refer to the \Application\GeneratedCode directory within your Build Environment. By using this template, it will be very easy to build the UI project for your target.

Now you can use the template project in the same manner as it was used for the provided examples to compile and link the binary.

After generating code, please follow these steps, in order to build your own UI application:

The SSH client should be still opened, the directory \share is the current directory.

Navigate to the subdirectory \Application and make the binary:

Finally, the application can be executed on the Raspberry Pi:

Console output

The SSH client is very helpful to receive error messages or to display simple debug or trace messages from your Embedded Wizard UI application.

It can be used for all trace statements from your Embedded Wizard UI applications or for all debug messages from your C code.

Accessing Hardware GPIOs

The example DeviceIntegration shows the principles concerning integration of devices into a UI application. In order to access the GPIOs of the Raspberry Pi hardware, the third-party library WiringPi is needed. Please download and install the WiringPi library first before trying to build the binary of the example.

In this sample application the following interactions are shown:

Transmitting a string

Switching a LED on/off

Receiving an event and a counter value when a hardware button is pressed

Since the Raspberry Pi hardware does not provide LEDs or buttons, please make the following connections:

The LED is connected to BCM_GPIO17 - it can be accessed as GPIO 0 via WiringPi. The button is connected to BCM_GPIO22 - it can be accessed as GPIO 3 via WiringPi.