Spectrum Analyser

Last update: 22/04/2025

Hardware repo

Firmware repo

First Person View (FPV) drones are a testament to the power of miniaturisation of electronics in recent years, with a few hundred gram drone capable of exceeding 70mph and accelerating faster than an F1 car. The FPV drone hobby has a strong culture of tinkering with many building their own drones from parts, especially historically, and this is a big reason why I became involved in the first place.

When flying drones in a group it is important to consider what frequency each is transmitting video at. The most typical band used for drones is the 5.8GHz band which is split up into around 8 non-overlapping video bands. Ideally drones will be transmitting at bands that are as far apart as possible and where there is minimal background interference. However, without a device capable of inspecting the activity in this frequency range, it is not obvious what the ideal bands are.

To tackle this problem, I decided to create a hand-held device that would be able to inspect the 5.8GHz band and report on the utilisation. The required features are:

Real-time update of signal levels
Graphical user interface
Multiple programs for different analyses
Button-based input
Battery powered with internal charge circuitry

RX5808

The heart of this project is the RX5808 radio module. This is a widely available and inexpensive System on Module (SoM) which is tunable within the 5.8GHz band and provides FM demodulation. Crucially for this project, it also outputs a real-time Received Signal Strength Indicator (RSSI) value for the centre frequency it is currently locked to.

Coming soon...

PCB Design

Coming soon...

Firmware

Coming soon...