Trying out the ExpEYES science and experimentation kit

Installing the software on the Raspberry Pi

The software for ExpEYES is capable of running on the Raspberry Pi. Because of the volunteer nature of the ExpEYES project, Raspberry Pi support is a work in progress, although it is constantly improving. The performance on the Raspberry Pi is obviously not as good as it is on some more powerful computers, but the system is perfectly usable and is a cheap way to create a dedicated platform for ExpEYES for your school or home workshop.

Thanks to the efforts of Georges Khasnadar, official Debian packages are available for ExpEYES, along with a number of other Linux platforms, so installation on the Raspberry Pi is quite simple. The following installation process works for Ubuntu, Mint, and Debian, and possibly a number of other distros, too.

Open an LXTerminal session on the Raspberry Pi and run the commands:

sudo apt-get update
sudo apt-get install expeyes

These commands should successfully complete the installation of everything needed for you to get start with ExpEYES on the Raspberry Pi. ExpEYES has a number of dependencies that are required for it to run under Linux: python, python-expeyes, python-imaging-tk, python-tk, grace, and tix. The developers recommend installing the python-numpy, python-pygrace, and python-scipy libraries on your system as well. During the installation, the installer should set up the dependencies by default; however, you can run the following command to make sure they are all installed:

sudo apt-get install python python-expeyes python-imaging-\
  tkpython-tk grace tix python-numpy python-scipy python-pygrace

Once you are sure you have all of the necessary modules installed, you are ready to start using ExpEYES on your Raspberry Pi. You should now notice that the ExpEYES GUI software is featured in the desktop start menu under Education, and opening this software should load a screen that looks similar to Figure 5.

Figure 5: The ExpEYES software runs quite well on the Raspberry Pi.

You can also download the .deb files directly from the Debian repository [4]; however, you're better off sticking with the apt-get install method unless you have a specific reason to prefer a manual installation.

Other Supported Platforms

ExpEYES can run on any computer that has a Python interpreter and a Python module allowing it to access the serial port. The USB interface has a device driver that presents the USB module as an RS232 (serial) port to the software applications. Communication with the ExpEYES Junior is possible in a number of ways, either by using the Python library, the C library, or the GUI that supports many experiments (more than 50). This, alongside the open source licence, allows for a huge amount of versatility and therefore lets you easily customize and expand the software to suit your particular application. It is also possible to add new experiments to the list, in many cases with only a few lines of Python code.

You can download the software to run these applications on a Windows PC or any other capable device because the software is written in Python. However, the installation process is fairly lengthy, so if you do not want to use the Raspberry Pi, I would strongly recommend using the Live CD.

You will also find a native Windows application; however, this apparently only supports the main oscilloscope program and seven of the 50+ experiments, so it is not as fully featured as the Python-based GUI. Full installation instructions for either of these methods of using ExpEYES on a Windows PC are available on the ExpEYES website [5]. The files are also included on the CD. You need to browse the WINEYES directory and read the winstall.html or README.TXT file for instructions.

You will also find an Android application for ExpEYES, which you can download from the Google Play Store [6]. This Android app will only work on more recent Android devices that are capable of USB OTG (On-the-Go) connections by using the necessary adapter cable, which you can purchase from Amazon and a number of other outlets. Not all of the experiments are included in this Android app, but more are being added all the time, and the default oscilloscope functionality is included (Figure 6).

Figure 6: ExpEYES Junior Android app comes with built-in oscilloscope functionality.