The main GUI program
====================

Start Applications->Education->ExpEYES-junior from the menu. A four channel
oscilloscope screen with several extra features will open as shown in
the figure. Various experiments can be selected from the menu.

.. _the-scope-junior-screen:
.. figure:: pics/eyes-junior-screen-en.png

    The ExpEYES-Junior main GUI

The main window looks like a low frequency four channel oscilloscope,
with some extra features, on the right side panel. Applications for
various experiments can be selected from the pulldown menu. A brief
description of the oscilloscope program is given below.

-  Any of the four inputs (A1, A2, IN1 or IN2) can be enabled using the
   corresponding checkbox. The input range can be selected by clicking
   on the menubutton on the right side of the checkbox. Select the
   desired input range from the popup menu.
-  There is another checkbox, to enable mathematical fitting of the data
   using :math:`V=V_0 sin(2\pi f t + \theta )+C` to show the amplitude and
   frequency.
-  The horizontal scale (time base) can be changed by a slider, from 2
   mS fullscale to 500 mS full scale.
-  The Checkbutton **Freeze**, allows to pause and resume the
   oscilloscope operation.
-  The Trigger level can be set by a slider, and there is a menubutton
   to select the trigger source.
-  To save the traces to a file, edit the filename and click on the
   **SaveTo** button.
-  Clicking on **FFT** shows the frequency spectrum of all the eneabled
   channels, appears on popup windows.

In addition to the Oscilloscope, there are several measurement/control
options available on the GUI, they are explained below.

-  If selected, the voltages at the inputs A1, A2, IN1 and IN2 are sampled
   every second and displayed.
-  The resistance connected between SEN and Ground is measured and
   displayed every second.
-  Clicking **Capacitance on IN1**, measures the value of the capacitor
   connected between IN1 and GND.
-  Clicking **Frequency on IN2**, measures the frequency of an external
   digital (TTL standard) pulse connected to IN2
-  SQ1 can be set using the same method as explained above.
-  The programmable volages PVS also set in a similar manner.
-  Checkbuttons are provided to control OD1 and CCS.

