I am planning on constructing a small oscilloscope using a 3.2 inch touch screen LCD as a display.

I have written some routines for a Microchip dsPIC33FJ128MC802 to read the touch screen and display some simple shapes.

The display is a HY-TFT320 which uses an SSD1289 LCD driver chip and an XPT2046 chip for the touch screen driver.

Now that I have got some of simple functions working I will now work on developing the oscilloscope.

Here I am feeding a sine wave from my signal generator into one of the inputs of the oscilloscope.  I still need to add a lot more functionality to make the oscilloscope useful.

Adjusting the trigger level.

Moving the signal traces on the screen.  The blue line is the second channel.

I have added a cursor for displaying the voltage at the specific point, the cursor can be moved around by touching the screen on the x axis, it automatically snaps to the signal on the y axis.  The value still needs scaling to display the correct voltage.  I am now going to get the cursor to display the time relative to the origin - the vertical yellow line that can also be moved in a similar manner.