Introduction
There is a considerable number of places on the Internet, including the Element14 site, showing useful information on the installation and settings of this brand new device; in the meantime a number of doubts and questions has raised about the touch screen settings, the on-screen keyboard installation and more. The goal of these notes is to depict a setup scenario as much complete as possible. The Raspberry PI 7" LCD Touch Screen display is the perfect replacement of a dedicated screen, with the plus of the optional on-screen keyboard.
To use this device in a Raspberry PI project requiring User Interaction it sounds almost difficult in applications like robotics, machines control, informative point, web access, sensors gauges etc.
A reliable solution exists and its name is Kivy: open source, not too difficult to install and is based on Python.
Note: the frame assembly of the Raspberry PI LCD Touch Screen display shown in the images of this post is available on the Drobott site. Don't forget to apply the Element14 discount code W0E49MYQ (10% off) reserved to the community users!
What raspbian release?
The first thing to do it to decide what raspbian image should be installed on the PI. If you have already a Raspberry PI with an existing raspbian version on it, you should install the hardware then power on the system and proceed with the software.
If you should start from scratch instead, I suggest to download the last raspbian updated image (2015-05-05-raspbian-wheezy.img at the date) from the raspberry.org site to create a bootable microSD card; you can choose between two different flavours: raspbian based on Debian wheezy or Debian jessie; this choice is up to you. At the actual date it seems that the Raspberry PI porting of the Jessie distribution has again some issues.
In both cases, the next step is an update/upgrade of the system.
$sudo apt-get update
$sudo apt-get upgrade
You should have noted that the system, also on first-boot will recognise the new display device without any special setting or display drivers to be installed.
Showing full HD videos on the screen
If you plan to use the screen to show full HD videos (1080x1920 pix) the better performances can be obtained reserving 128 Mb of shared memory to the video card. The amount of shared memory (64 Mb by default) can be changed with the raspi-config command and selecting the menu options shown below.
Select Advanced Options from the main menu.
Select Memory Split from the next screen.
Then, write 128 instead of 64 (the default settings). Confirm and exit, reboot.
On-Screen keyboard
Installing the on-screen keyboard is not the solution to develop software or write long text documents on the Raspberry PI, but it is a must-to-have to make complete the user interaction options. Installing the keyboard is a very simple operation that can be done with a single command from the terminal:
sudo apt-get install matchbox-keyboard
just as it is explained in the product document page on Element14. The documentation says that the keyboard (after installation and reboot) is accessible on-screen from the Menu->Accessories->Keyboard. Doing several installations I have verified that the keyboard is not always listed as a new menu option; one of the reasons depends on the previous presence of a physical keyboard connected to the Raspberry or not. To be sure that the on-screen keyboard is added to the desktop menu after installation the better choice is to manage the Raspberry PI from remote via SSH.
The on-screen keyboard can be shown by your applications or bash scripts with the command
matchbox-keyboard
Enabling the touch-screen
Depending on the current status of the linux settings, maybe you don't see the mouse pointer on the screen and the touch screen is unresponsive; the touch screen uses SPI to communicate with the Raspberry PI so it should be enabled, while by default the SPI kernel modules are not loaded.
From the terminal launch the command
sudo raspi-config
then from the character graphic menu follow the steps shown below.
Select Advanced Options from the main menu.
Select the SPI menu option.
Confirm to enable the SPI module and the next screen to load the SPI kernel modules on boot by default. Then, exit and reboot the system.
Congratulations!
Now your system is ready to use the full features of the 7 inches LCD display and touch screen.
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