HI again, i ported this
" https://github.com/s-marley/ESP32_FFT_VU"
for smartMatrix by including neomatrix_config.h and made some changes to sketch. now display is just white not showing actual thing. i uploaded the code to github if anyone want to have a look on it.
https://github.com/alpha815/esp32-spectrum-analyzer
BTW i am using smartmatrix_gfx by marcmerlin
“https://github.com/marcmerlin/SmartMatrix_GFX”
any help will be highly appreciated.