From Dan Kisling on Hackaday.io:

Spectrum analyzers provide a visual aid to circuit design and signal processing critical to troubleshooting and understanding how frequencies both affect and are affected by electronics. While the educational and practical applications of such devices are extensive, the availability of such devices are often limited by cost and usability. Similarly, low cost designs often suffer from lack of range or resolution. Our design overcomes cost and limited usage by implementing a hybrid superheterodyning and fast fourier technique. The superheterodyning aspect grants the device a robust range while the fast fourier and digital calculations allow for imperfections in devices to have lower impact on the signal integrity. Additionally, cost and availability were made more attractive by using the Raspberry Pi, a widely available and low cost computer, as the central controller of the system.

Read more and see more from Dan Kisling on YouTube

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