0.91寸OLED液晶屏显示模块 IIC 12832液晶屏 兼容3.3v-5V

【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();

}