This is a simple PC voltage oscilloscope using only a PIC12F675, a 20MHz oscillator, and a RS232 level shifter.
The PIC takes a sample on GP2, immediately sends it to the PC at 115,200 baud using an software asynchronous serial routine, and repeats. It sends a 8-bit value that is read by the Visual Basic software and displayed on the screen. The Visual Basic software deduces the time period between submissions and adjusts the display accordingly.
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