VU-meter Esp8266 - WS2812B

This is a test of hardware fft with Kendryte K210 / Sipeed M1 dock.

Using built in MEMS microphone

code

https://github.com/MrJBSwe/fft_lcd

https://github.com/cnlohr/colorchord/tree/master/embedded8266

I have not yet tried it but it seems do do the trick. CNLohr has done a great job !!

This really demonstrates what can be done with the Esp8266 and a Teensy 3.1

by Frank Bösing

https://github.com/FrankBoesing/ILI9341_t3

Download Video as MP4

This is probably the simplest solution

http://www.mix-sig.com/index.php/msgeq7-seven-band-graphic-equalizer-display-filter

https://forums.adafruit.com/viewtopic.php?f=19&t=40348

http://www.whatimade.today/graphic-equalizer-using-esp8266-msgeq7-ws2812/

Here is a snippet on how to play with the fix_fft in winamp. The reason for this is, it gives a good idea if it's worth the effort to implement in the Esp8266 ( which I think it is ;-). It's just a quick & dirty hack... to get a feeling.

Current goal :

* Sample with Esp8266 ADC in approximate 10kHz

* 8 bit fix_fft: 16 fft bin is enough ( but I'll probably calculate more, or use a filter ;-)

* Predict beat

Track active frequencies with histogram - predict beat

This-Is-Your-Brain-On-Music

A different way to visualize rhythm - John Varney

Beat detection C++

Beatbots

* Make something fun..."synchronized party stuff"

Download Video as MP4

// http://www.Planet-Source-Code.com/vb/scripts/ShowCode.asp?txtCodeId=960&lngWId=3
// By: David Overton
// vis_spectrum.cpp

winampVisModule waModule = {
  ...
 1, // spectrumNch
 1, // waveformNch
 ...
};

char g_real[600];
char g_imag[600];

OnPluginRender  

int n=0;  

// Get a grip on which ADC rate would be necessary
// Divide 44100/4 = 11025 sample rate
for( int i=0; i<576; i+=4 /* play with sample rate 1-9 */)
{
    g_real[n]=mod->waveformData[0][i];
    ++n;
}

fix_fft(g_real, g_imag, 6/* 2^6 = number of FFT points */, 0); 

for (int i=0; i<32/* number of bins = FFT points/2 */; i++)
{
  // just a "scale factor" not much thought put into it.....
    g_real[i] = 8.6*( (sqrt((float)g_real[i] * (float)g_real[i] + (float)g_imag[i] * (float)g_imag[i])));

}


HBRUSH NewBrush  = CreateSolidBrush(RGB(255, 255, 255));
HBRUSH hbrushOld = (HBRUSH)SelectObject(Plugin.hMemDC, NewBrush);

int x=7;
int y;

/* just hard coded values without respect of actual size */
/* ignore the upper half of the spectrum */
for( int i=0; i<16/* number of bins to display*/; ++i )  
{   
    y=118-g_real[i];
    if( y<8 )
        y=8;
    Rectangle(Plugin.hMemDC, x, y, x+16, 118);
    x+=16; /* bar width*/
}


SelectObject(Plugin.hMemDC, hbrushOld);
DeleteObject (NewBrush) ;
 

.....  // Blit all to hDC

I think the Esp8266 is fast enough and CNLohr has made excellent and stable drivers for the WS2812B. With 160MHz there is plenty of time to do fun stuff and receive commands over WiFi. I think the limitations lies primarily in the WS2812B transfer rate ( approx=NLEDx3x8x1.25µs + 50µs ). You can probably update several strips simultaneously ( taking advantage of the delays in the ws2812 driver )

My guess is POV & VU meter could very "easily" be implemented with these building blocks ...on a wheel or party dress ...the ball is now yours !

starting point .......

https://www.youtube.com/watch?v=tCmaOb-VAEo

http://forum.arduino.cc/index.php/topic,38153.0.html