【Arduino】168种传感器模块系列实验（资料代码+仿真编程+图形编程）
实验一百三十六：0.91寸OLED液晶屏显示模块 IIC 12832液晶屏 兼容3.3v-5V
项目二十三：黄色屏声音可视化器
实验接线: max9814接A0
oled模块 Ardunio Uno
GND---------GND接地线
VCC---------5V 接电源
SDA---------A4
SCL ------- A5
*/
#include "arduinoFFT.h"
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define SAMPLES 64 // power of 2
#define SAMPLING_FREQ 8000 // 12 kHz Fmax = sampleF /2
#define AMPLITUDE 100 // 灵敏度
#define FREQUENCY_BANDS 14
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32
#define BARWIDTH 11
#define BARS 11
#define ANALOG_PIN A0
#define OLED_RESET -1 // 重置引脚 #（如果共享 Arduino 重置引脚，则为 -1）
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
double vImag[SAMPLES];
double vReal[SAMPLES];
unsigned long sampling_period_us;
arduinoFFT fft = arduinoFFT(vReal, vImag, SAMPLES, SAMPLING_FREQ);
//调整参考以去除背景噪声
float reference = log10(60.0);
double coutoffFrequencies[FREQUENCY_BANDS];
void setup() {
// SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
for (;;); // Don't proceed, loop forever
}
// Setup display
display.clearDisplay();
display.display();
display.setRotation(0);
display.invertDisplay(false);
sampling_period_us = (1.0 / SAMPLING_FREQ ) * pow(10.0, 6);
// 计算截止频率，以对数标度为基数 POt
double basePot = pow(SAMPLING_FREQ / 2.0, 1.0 / FREQUENCY_BANDS);
coutoffFrequencies[0] = basePot;
for (int i = 1 ; i < FREQUENCY_BANDS; i++ ) {
coutoffFrequencies[i] = basePot * coutoffFrequencies[i - 1];
}
// 绘制虚线以分离频段
for (int i = 0; i < BARS - 1 ; i++) {
for (int j = 0; j < SCREEN_HEIGHT ; j += 4) {
display.writePixel((i + 1)*BARWIDTH + 2 , j, SSD1306_WHITE );
}
}
display.drawRect(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, SSD1306_WHITE);
}
int oldHeight[20];
int oldMax[20];
double maxInFreq;
void loop() {
// 采样
for (int i = 0; i < SAMPLES; i++) {
unsigned long newTime = micros();
int value = analogRead(ANALOG_PIN);
vReal[i] = value;
vImag[i] = 0;
while (micros() < (newTime + sampling_period_us)) {
yield();
}
}
// 计算 FFT
fft.DCRemoval();
fft.Windowing(FFT_WIN_TYP_HAMMING, FFT_FORWARD);
fft.Compute(FFT_FORWARD);
fft.ComplexToMagnitude();
double median[20];
double max[20];
int index = 0;
double hzPerSample = (1.0 * SAMPLING_FREQ) / SAMPLES; //
double hz = 0;
double maxinband = 0;
double sum = 0;
int count = 0;
for (int i = 2; i < (SAMPLES / 2) ; i++) {
count++;
sum += vReal[i];
if (vReal[i] > max[index] ) {
max[index] = vReal[i];
}
if (hz > coutoffFrequencies[index]) {
median[index] = sum / count;
sum = 0.0;
count = 0;
index++;
max[index] = 0;
median[index] = 0;
}
hz += hzPerSample;
}
// 计算每个频段的中值和最大值
if ( sum > 0.0) {
median[index] = sum / count;
if (median[index] > maxinband) {
maxinband = median[index];
}
}
int bar = 0;
for (int i = FREQUENCY_BANDS - 1; i >= 3; i--) {
int newHeight = 0;
int newMax = 0;
// 计算实际分贝
if (median[i] > 0 && max[i] > 0 ) {
newHeight = 20.0 * (log10(median[i] ) - reference);
newMax = 20.0 * (log10(max[i] ) - reference);
}
// 调整最小和最大级别
if (newHeight < 0 || newMax < 0) {
newHeight = 1;
newMax = 1;
}
if (newHeight >= SCREEN_HEIGHT - 2) {
newHeight = SCREEN_HEIGHT - 3;
}
if (newMax >= SCREEN_HEIGHT - 2) {
newMax = SCREEN_HEIGHT - 3;
}
int barX = bar * BARWIDTH + 5;
// 删除旧水平中位数
if (oldHeight[i] > newHeight) {
display.fillRect(barX, newHeight + 1, 7, oldHeight[i], SSD1306_BLACK);
}
// 删除旧的最大级别
if ( oldMax[i] > newHeight) {
for (int j = oldMax[i]; j > newHeight; j -= 2) {
display.drawFastHLine(barX , j, 7, SSD1306_BLACK);
}
}
// 绘制新的最大级别
for (int j = newMax; j > newHeight; j -= 2) {
display.drawFastHLine(barX , j, 7, SSD1306_WHITE);
}
// 绘制新的级别中位数
display.fillRect(barX , 1, 7, newHeight, SSD1306_WHITE);
oldMax[i] = newMax;
oldHeight[i] = newHeight;
bar++;
}
display.drawFastHLine(0 , SCREEN_HEIGHT - 1, SCREEN_WIDTH, SSD1306_WHITE);
display.display();
}
