A while back I posted a video that showed a strange bug that was happening with my oscilloscope LCD program. It used U8GLib or the Universal 8 Bit Graphics Library. The video is available at, http://youtu.be/1qPy6FVSllY
** UPDATE ** This problem is caused by updating the data while it is being displayed. The update must not happen within the display loop.
Then I made a perfectly working oscilloscope using the Universal TFT Library and a better LCD. So then I thought I would go back and see what was the problem with U8GLib.
To rule out the LCD display I purchased a KS0108 compatible display because I could run it with its own support software or with the U8GLib. With the KS0108 driver, I could not scale the amplitude of the input waveform, a new issue. However the sine wave turned out perfectly using the KS0108 driver. Then the same software really went crazy when I tried to use the U8GLib drivers. Here is the video on YouTube, http://youtu.be/l-I4vf83OIc
Does anyone else have this problem or know of a solution??
Here is a picture of what the display should look like;
But this is what happens when you move the position control to center the sine wave;