this is Arduino sketch for esp32 spectrum analyzer
this is just a demonstration of fast led library, smartmatrix3 and Arduino FFT library working together to display frequency bands on 32x16 RGB led matrix.
but this code can easily be adapted for any display resolution. This code is heavily adapted from Scott Marley code for ws2812 leds.
FFT is performed by esp32 by sampling audio signal on PIN-35 at sampling rate of 1024.i heavly adopted this code from Scott Marley "ESP32 spectrum analyzer VU meter using arduinoFFT and a FastLED matrix" that is compatible for WS2812 based MATRIX. It is bassed on fastled libraray that is why it is fairly easily to adopt it for SMARTMATRIX3 library. This sketch contain five audio reactive patterns and a static pattern,it is not audio reactive. which is example of fastled library. I will try to add more static modes if i had time. patters can be switched between by pressing button of esp32 named as BOOT.
i will add few links for you to get going.
Scott Marley video: "https://www.youtube.com/watch?v=Mgh2WblO5_c"
"https://github.com/s-marley/ESP32_FFT_VU"
what is not working :
waterfall pattern from original sketch was not working due to improper" XY " coordination that's why i deleted it.
you may need to tune few parameters based on how you feed audio signal to esp32 play around with amplitude and noise value .
I am using this circuit for line in:
"https://github.com/atuline/WLED/raw/assets/media/WLED_Line_In_Wiring.png"
and it works well, i also tried MAX9814 but due to bad frequency response (or something else) it does not work very well.
i am not a programmer but i will try to help if you need.
libraries : smartmatrix3: https://github.com/pixelmatix/SmartMatrix fastled: https://github.com/FastLED/FastLED arduinoFFT: https://github.com/kosme/arduinoFFT and a short video with max9814 mic input, it does not look pretty well with mic input but i will upload with a line-in version very soon. https://youtu.be/gD1bOLCC0y8