【Arduino 动手做】FastLED矩阵的ESP32频谱分析仪VU表
频谱分析仪 VU 表在 ESP32 上运行 40kHz FFT 并输出到 16 x 16 FastLED 矩阵。该代码与最初由 G6EJD 编写的此示例进行了大量修改。演示
如果您打算使用此代码，建议您观看下面的 YouTube 视频，了解其工作原理。请注意，由于视频的制作，代码已更改为使用 FastLED Neomatrix，这要归功于 VonHirsch。请参阅下面的“安装和代码使用”。
设置电路
矩阵将从线路输入或麦克风运行，因此请选择适合您的设置。为按钮选择图钉时，请小心。ESP32 上的一些引脚没有上拉电阻，如果您选择其中一个，按钮将不起作用！当我测试时，我发现 D2 不起作用，但 D4 有效，所以我选择了那个。
线路输入
输入的立体声信号首先使用两个 10K 电阻器转换为单声道，然后通过一个 100nF 电容器来阻断直流。然后，信号由两个 100k 电阻器偏置到 3.3V / 2 = 1.65V，以便 ADC 读取。这些值都不是关键的。电阻器应为 10k 或更高，并且每对应匹配。我尝试了从100nF 到10uF 的电容器，但没有注意到结果有任何差异。引脚 D5 是 LED 数据引脚，连接到矩阵中的第一个 LED。引脚 D2 连接到一个瞬时按钮，用于更改显示模式。
麦克风
这比 line in 方法简单得多，但您将受限于麦克风的灵敏度可以检测到的频率。您需要一个带有板载放大功能的麦克风，通常类似于 MAX4466 的东西，可以从 eBay 或 alixepress 便宜地购买。使用 I2S 麦克风会获得更好的结果，但这超出了本项目的范围。调高您拥有的任何麦克风的增益。麦克风应连接到 GND、3V3，输出引脚应连接到 D35。引脚 D5 是 LED 数据引脚，连接到矩阵中的第一个 LED。引脚 D2 连接到一个瞬时按钮，用于更改显示模式。
安装和代码使用
1. 下载此存储库并打开 ESP32_FFT_VU.ino。
2. 您将需要 Arduino 库管理器中的 FastLED、Neomatrix 和 EasyButton 库。您还需要 arduinoFFT 库。在撰写本文时，库管理器版本 arduinoFFT 存在一个阻止工作的错误，因此请从 GitHub 存储库下载它并从 zip 文件安装它。DCRemoval()
3. 观看视频以了解如何使用它。
4. 要将其自定义为您自己的矩阵布局，请阅读 Adafruit 上的 Neomatrix 布局。
控制
矩阵通过单个按钮进行控制。这些功能包括：
• 单击：更改模式
• 长按：更改亮度
• 2 秒内按下 3 个按钮：设置为自动更改模式
• 2 秒内按下 5 个按钮：关闭显示屏
【Arduino 动手做】FastLED矩阵的ESP32频谱分析仪VU表
项目代码// (Heavily) adapted from https://github.com/G6EJD/ESP32-8266-Audio-Spectrum-Display/blob/master/ESP32_Spectrum_Display_02.ino
// Adjusted to allow brightness changes on press+hold, Auto-cycle for 3 button presses within 2 seconds
// Edited to add Neomatrix support for easier compatibility with different layouts.
#include <FastLED_NeoMatrix.h>
#include <arduinoFFT.h>
#include <EasyButton.h>
#define SAMPLES 1024 // Must be a power of 2
#define SAMPLING_FREQ 40000 // Hz, must be 40000 or less due to ADC conversion time. Determines maximum frequency that can be analysed by the FFT Fmax=sampleF/2.
#define AMPLITUDE 1000 // Depending on your audio source level, you may need to alter this value. Can be used as a 'sensitivity' control.
#define AUDIO_IN_PIN 35 // Signal in on this pin
#define LED_PIN 5 // LED strip data
#define BTN_PIN 4 // Connect a push button to this pin to change patterns
#define LONG_PRESS_MS 200 // Number of ms to count as a long press
#define COLOR_ORDER GRB // If colours look wrong, play with this
#define CHIPSET WS2812B // LED strip type
#define MAX_MILLIAMPS 2000 // Careful with the amount of power here if running off USB port
const int BRIGHTNESS_SETTINGS = {5, 70, 200};// 3 Integer array for 3 brightness settings (based on pressing+holding BTN_PIN)
#define LED_VOLTS 5 // Usually 5 or 12
#define NUM_BANDS 16 // To change this, you will need to change the bunch of if statements describing the mapping from bins to bands
#define NOISE 500 // Used as a crude noise filter, values below this are ignored
const uint8_t kMatrixWidth = 16; // Matrix width
const uint8_t kMatrixHeight = 16; // Matrix height
#define NUM_LEDS (kMatrixWidth * kMatrixHeight) // Total number of LEDs
#define BAR_WIDTH (kMatrixWidth/ (NUM_BANDS - 1))// If width >= 8 light 1 LED width per bar, >= 16 light 2 LEDs width bar etc
#define TOP (kMatrixHeight - 0) // Don't allow the bars to go offscreen
#define SERPENTINE true // Set to false if you're LEDS are connected end to end, true if serpentine
// Sampling and FFT stuff
unsigned int sampling_period_us;
byte peak[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; // The length of these arrays must be >= NUM_BANDS
int oldBarHeights[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int bandValues[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
double vReal;
double vImag;
unsigned long newTime;
arduinoFFT FFT = arduinoFFT(vReal, vImag, SAMPLES, SAMPLING_FREQ);
// Button stuff
int buttonPushCounter = 0;
bool autoChangePatterns = false;
EasyButton modeBtn(BTN_PIN);
// FastLED stuff
CRGB leds;
DEFINE_GRADIENT_PALETTE( purple_gp ) {
0, 0, 212, 255, //blue
255, 179, 0, 255 }; //purple
DEFINE_GRADIENT_PALETTE( outrun_gp ) {
0, 141, 0, 100, //purple
127, 255, 192, 0, //yellow
255, 0, 5, 255 };//blue
DEFINE_GRADIENT_PALETTE( greenblue_gp ) {
0, 0, 255,60, //green
64, 0, 236, 255, //cyan
128, 0, 5, 255, //blue
192, 0, 236, 255, //cyan
255, 0, 255,60 }; //green
DEFINE_GRADIENT_PALETTE( redyellow_gp ) {
0, 200, 200,200, //white
64, 255, 218, 0, //yellow
128, 231, 0, 0, //red
192, 255, 218, 0, //yellow
255, 200, 200,200 }; //white
CRGBPalette16 purplePal = purple_gp;
CRGBPalette16 outrunPal = outrun_gp;
CRGBPalette16 greenbluePal = greenblue_gp;
CRGBPalette16 heatPal = redyellow_gp;
uint8_t colorTimer = 0;
// FastLED_NeoMaxtrix - see https://github.com/marcmerlin/FastLED_NeoMatrix for Tiled Matrixes, Zig-Zag and so forth
FastLED_NeoMatrix *matrix = new FastLED_NeoMatrix(leds, kMatrixWidth, kMatrixHeight,
NEO_MATRIX_TOP + NEO_MATRIX_LEFT +
NEO_MATRIX_ROWS + NEO_MATRIX_ZIGZAG +
NEO_TILE_TOP + NEO_TILE_LEFT + NEO_TILE_ROWS);
void setup() {
Serial.begin(115200);
FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection(TypicalSMD5050);
FastLED.setMaxPowerInVoltsAndMilliamps(LED_VOLTS, MAX_MILLIAMPS);
FastLED.setBrightness(BRIGHTNESS_SETTINGS);
FastLED.clear();
modeBtn.begin();
modeBtn.onPressed(changeMode);
modeBtn.onPressedFor(LONG_PRESS_MS, brightnessButton);
modeBtn.onSequence(3, 2000, startAutoMode);
modeBtn.onSequence(5, 2000, brightnessOff);
sampling_period_us = round(1000000 * (1.0 / SAMPLING_FREQ));
}
void changeMode() {
Serial.println("Button pressed");
if (FastLED.getBrightness() == 0) FastLED.setBrightness(BRIGHTNESS_SETTINGS);//Re-enable if lights are "off"
autoChangePatterns = false;
buttonPushCounter = (buttonPushCounter + 1) % 6;
}
void startAutoMode() {
autoChangePatterns = true;
}
void brightnessButton() {
if (FastLED.getBrightness() == BRIGHTNESS_SETTINGS)FastLED.setBrightness(BRIGHTNESS_SETTINGS);
else if (FastLED.getBrightness() == BRIGHTNESS_SETTINGS) FastLED.setBrightness(BRIGHTNESS_SETTINGS);
else if (FastLED.getBrightness() == BRIGHTNESS_SETTINGS) FastLED.setBrightness(BRIGHTNESS_SETTINGS);
else if (FastLED.getBrightness() == 0) FastLED.setBrightness(BRIGHTNESS_SETTINGS); //Re-enable if lights are "off"
}
void brightnessOff(){
FastLED.setBrightness(0);//Lights out
}
void loop() {
// Don't clear screen if waterfall pattern, be sure to change this is you change the patterns / order
if (buttonPushCounter != 5) FastLED.clear();
modeBtn.read();
// Reset bandValues[]
for (int i = 0; i<NUM_BANDS; i++){
bandValues = 0;
}
// Sample the audio pin
for (int i = 0; i < SAMPLES; i++) {
newTime = micros();
vReal = analogRead(AUDIO_IN_PIN); // A conversion takes about 9.7uS on an ESP32
vImag = 0;
while ((micros() - newTime) < sampling_period_us) { /* chill */ }
}
// Compute FFT
FFT.DCRemoval();
FFT.Windowing(FFT_WIN_TYP_HAMMING, FFT_FORWARD);
FFT.Compute(FFT_FORWARD);
FFT.ComplexToMagnitude();
// Analyse FFT results
for (int i = 2; i < (SAMPLES/2); i++){ // Don't use sample 0 and only first SAMPLES/2 are usable. Each array element represents a frequency bin and its value the amplitude.
if (vReal > NOISE) { // Add a crude noise filter
/*8 bands, 12kHz top band
if (i<=3 ) bandValues+= (int)vReal;
if (i>3 && i<=6) bandValues+= (int)vReal;
if (i>6 && i<=13 ) bandValues+= (int)vReal;
if (i>13&& i<=27 ) bandValues+= (int)vReal;
if (i>27&& i<=55 ) bandValues+= (int)vReal;
if (i>55&& i<=112) bandValues+= (int)vReal;
if (i>112 && i<=229) bandValues+= (int)vReal;
if (i>229 ) bandValues+= (int)vReal;*/
//16 bands, 12kHz top band
if (i<=2 ) bandValues+= (int)vReal;
if (i>2 && i<=3) bandValues+= (int)vReal;
if (i>3 && i<=5) bandValues+= (int)vReal;
if (i>5 && i<=7) bandValues+= (int)vReal;
if (i>7 && i<=9) bandValues+= (int)vReal;
if (i>9 && i<=13 ) bandValues+= (int)vReal;
if (i>13&& i<=18 ) bandValues+= (int)vReal;
if (i>18&& i<=25 ) bandValues+= (int)vReal;
if (i>25&& i<=36 ) bandValues+= (int)vReal;
if (i>36&& i<=50 ) bandValues+= (int)vReal;
if (i>50&& i<=69 ) bandValues += (int)vReal;
if (i>69&& i<=97 ) bandValues += (int)vReal;
if (i>97&& i<=135) bandValues += (int)vReal;
if (i>135 && i<=189) bandValues += (int)vReal;
if (i>189 && i<=264) bandValues += (int)vReal;
if (i>264 ) bandValues += (int)vReal;
}
}
// Process the FFT data into bar heights
for (byte band = 0; band < NUM_BANDS; band++) {
// Scale the bars for the display
int barHeight = bandValues / AMPLITUDE;
if (barHeight > TOP) barHeight = TOP;
// Small amount of averaging between frames
barHeight = ((oldBarHeights * 1) + barHeight) / 2;
// Move peak up
if (barHeight > peak) {
peak = min(TOP, barHeight);
}
// Draw bars
switch (buttonPushCounter) {
case 0:
rainbowBars(band, barHeight);
break;
case 1:
// No bars on this one
break;
case 2:
purpleBars(band, barHeight);
break;
case 3:
centerBars(band, barHeight);
break;
case 4:
changingBars(band, barHeight);
break;
case 5:
waterfall(band);
break;
}
// Draw peaks
switch (buttonPushCounter) {
case 0:
whitePeak(band);
break;
case 1:
outrunPeak(band);
break;
case 2:
whitePeak(band);
break;
case 3:
// No peaks
break;
case 4:
// No peaks
break;
case 5:
// No peaks
break;
}
// Save oldBarHeights for averaging later
oldBarHeights = barHeight;
}
// Decay peak
EVERY_N_MILLISECONDS(60) {
for (byte band = 0; band < NUM_BANDS; band++)
if (peak > 0) peak -= 1;
colorTimer++;
}
// Used in some of the patterns
EVERY_N_MILLISECONDS(10) {
colorTimer++;
}
EVERY_N_SECONDS(10) {
if (autoChangePatterns) buttonPushCounter = (buttonPushCounter + 1) % 6;
}
FastLED.show();
}
// PATTERNS BELOW //
void rainbowBars(int band, int barHeight) {
int xStart = BAR_WIDTH * band;
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
for (int y = TOP; y >= TOP - barHeight; y--) {
matrix->drawPixel(x, y, CHSV((x / BAR_WIDTH) * (255 / NUM_BANDS), 255, 255));
}
}
}
void purpleBars(int band, int barHeight) {
int xStart = BAR_WIDTH * band;
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
for (int y = TOP; y >= TOP - barHeight; y--) {
matrix->drawPixel(x, y, ColorFromPalette(purplePal, y * (255 / (barHeight + 1))));
}
}
}
void changingBars(int band, int barHeight) {
int xStart = BAR_WIDTH * band;
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
for (int y = TOP; y >= TOP - barHeight; y--) {
matrix->drawPixel(x, y, CHSV(y * (255 / kMatrixHeight) + colorTimer, 255, 255));
}
}
}
void centerBars(int band, int barHeight) {
int xStart = BAR_WIDTH * band;
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
if (barHeight % 2 == 0) barHeight--;
int yStart = ((kMatrixHeight - barHeight) / 2 );
for (int y = yStart; y <= (yStart + barHeight); y++) {
int colorIndex = constrain((y - yStart) * (255 / barHeight), 0, 255);
matrix->drawPixel(x, y, ColorFromPalette(heatPal, colorIndex));
}
}
}
void whitePeak(int band) {
int xStart = BAR_WIDTH * band;
int peakHeight = TOP - peak - 1;
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
matrix->drawPixel(x, peakHeight, CHSV(0,0,255));
}
}
void outrunPeak(int band) {
int xStart = BAR_WIDTH * band;
int peakHeight = TOP - peak - 1;
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
matrix->drawPixel(x, peakHeight, ColorFromPalette(outrunPal, peakHeight * (255 / kMatrixHeight)));
}
}
void waterfall(int band) {
int xStart = BAR_WIDTH * band;
double highestBandValue = 60000; // Set this to calibrate your waterfall
// Draw bottom line
for (int x = xStart; x < xStart + BAR_WIDTH; x++) {
matrix->drawPixel(x, 0, CHSV(constrain(map(bandValues,0,highestBandValue,160,0),0,160), 255, 255));
}
// Move screen up starting at 2nd row from top
if (band == NUM_BANDS - 1){
for (int y = kMatrixHeight - 2; y >= 0; y--) {
for (int x = 0; x < kMatrixWidth; x++) {
int pixelIndexY = matrix->XY(x, y + 1);
int pixelIndex = matrix->XY(x, y);
leds = leds;
}
}
}
}
【Arduino 动手做】FastLED矩阵的ESP32频谱分析仪VU表
【Arduino 动手做】FastLED矩阵的ESP32频谱分析仪VU表项目链接：https://www.youtube.com/watch?v=Mgh2WblO5_c
项目作者：斯科特·马利，ALTech DIY
项目视频 ：https://www.youtube.com/watch?v=26SWWaKUnCg&t=551s
项目代码：https://github.com/s-marley/ESP32_FFT_VU
arduinoFFT库：https://github.com/kosme/arduinoFFT
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