A search for related projects
I always start out new projects be making sure I don't re-invent the wheel.
A quick check of ongoing Hackaday (and other) projects returned many examples of visual spectrum analyzers. Some of them are simple LED strips, and others are full Matrix displays. Some use a microphone for their input; others use line inputs, Bluetooth or even audio files. Other major variations between different analyzers were the number of specific frequency bands that are measured, and how the signal strengths are displayed.
None of the ones I found had anywhere near enough Bands form my liking, so I decided it was worth continuing with my project.
Sometimes it's more fun to show where I'm at now, and then explain how I got there.. So here are my current specs.
- Bands: 59 Bands, spanning 55 Hz - 17163 Hz (8.25 Octaves)
- Audio Samples per FFT: 4096 samples @ 36 kHz
- FFT Frequency Bins: 2048 bins (8.79 Hz each)
- Display Update interval: 27 mSec (37 Hz)
- Audio to Visual Latency: Max 40 mSec (14 mSec acquisition + 26 mSec FFT & display)
But, going back to the beginning... I find it useful to start my projects with a rough set of system Requirements. This helps me to clarify my goals, and it gives me a place to return to when it's time for me to evaluate how well (or otherwise) the project is going.
So my first Project log will start there, and then we'll see how it goes.