He wanted to improve on the design though, making a smaller unit with a greatly reduced bill-of-materials and with a more streamlined design, so he came up with this STM32-based oscilloscope.

Even so, we can still think of plenty of practical uses for a ~$7 oscilloscope. If you do decide to add some front-end circuitry to change to voltage range, you can set them in the app ...

An oscilloscope gives the following display for the electricity from a battery. Figure caption, Oscilloscope trace showing battery voltage: a straight horizontal line at the top of the screen.