The build relies on a 20×2 character VFD display that looks great, with high brightness and excellent contrast. It can be easily driven from a microcontroller, as it has a controller on board ...

With an off-the-shelf LCD, this mess of wires and boards turns into an auto-scanning spectrum analyzer that’s also able to put video from a drone onto a screen.

Figure 2 – The RSA306 connected to a Mac laptop running Windows 8. The harmonics from an Arduino controller are being measured. The regular spectrum and waterfall are displayed. As you might imagine, ...