Following a neat tutorial from [Dave Jones], [Andrew] came up with a very simple way to make a Bode plot in real-time with an oscilloscope, a microcontroller, and a few off-the-shelf parts.

How to read Bode plots to assess dynamic control behavior of a power-supply design. Observing Bode plots from an example voltage regulator to observe control-loop speed and stability.

For example, when networks are cascaded so their gains multiply, the overall gain in decibels is found by simple addition. Bode plots are unitless on the vertical (ratio) axes.