Arduino的吉他音符检测器(2)_haoDIY_音响电子电脑科技DIY小制作发明

该代码可以看完整的附录中。

步骤4：步骤4：测试

在三个阶段的音调检测器。完成试验1和试验2在你建的音频输入电路和上传代码到你的Arduino。完成测试3在你构建的七段显示器和LED电路。

1。测试麦克风阅读任何声音，代码打印相应频率的连续监测在Arduino的编程环境。用你的声音通过麦克风的这个阶段的测试声源。在我们的项目中，我们遇到了一些麻烦，接线时麦克风。确保您使用的是适当的渠道上的麦克风。

2。测试你的设备是检测特定频率的合理。拿着麦克风4 - 6英寸的吉他琴弦，检查显示的频率在串行监测符合预期的频率在每一个音符。

以上是从什么ampthreshold样品试验确定的使用价值。如果你遇到了问题检测某些频率，尝试改变一些门槛值。两试验分别在20和一个测试阈值记录阈值25的记录。正如你可以看到上面的图，电路难以在更高的频率检测记录。消除一些静态的，确保你在一个安静的房间里几乎没有任何环境噪声测试。

三.试验表明，七段显示器和相关的LED显示正确的注。2重复试验，但是这一次看七段显示反馈，相对于串行监测。项目虽然很敏感，如某些笔记（尤其是E4）是嘈杂或难回暖。

步骤5：结论，来源，和附录

我们组是由五个肯塔基大学的学生学习电气和计算机工程。我们开发这个项目的一个信号与系统（EE 421）课程。请参考我们的网站，diracakteers '基音检测的响应，其中包括一个博客我们的进步而发展这种装置和一个描述音高与频率。

来源

Arduino的音频输入Amanda Ghassaei（amandaghassaei）

Arduino的频率检测Amanda Ghassaei（amandaghassaei）

Arduino的吉他调谐器通过nikoala3

附录：

<p>//Modified and used by Dirackteers<br>//
//generalized wave freq detection with 38.5kHz sampling rate and interrupts
//by Amanda Ghassaei
//https://www.instructables.com/id/Arduino-Frequency-Detection/
//Sept 2012</p><p>/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
*</p><p>/data storage variables
byte newData = 0;
byte prevData = 0;
unsigned int time = 0;//keeps time and sends values to store in timer[] occasionally
int timer[10];//storage for timing of events
int slope[10];//storage for slope of events
unsigned int totalTimer;//used to calculate period
unsigned int period;//storage for period of wave
byte index = 0;//current storage index
float frequency;//storage for frequency calculations
int maxSlope = 0;//used to calculate max slope as trigger point
int newSlope;//storage for incoming slope data</p><p>//variables for decided whether you have a match
byte noMatch = 0;//counts how many non-matches you've received to reset variables if it's been too long
byte slopeTol = 3;//slope tolerance- adjust this if you need
int timerTol = 10;//timer tolerance- adjust this if you need</p><p>//variables for amp detection
unsigned int ampTimer = 0;
byte maxAmp = 0;
byte checkMaxAmp;
byte ampThreshold = 30;//raise if you have a very noisy signal</p><p>void setup(){
  
  Serial.begin(9600);</p><p>  pinMode(2,OUTPUT); // segment a
  pinMode(3,OUTPUT); // segment b
  pinMode(4,OUTPUT); // segment c
  pinMode(5,OUTPUT); // segment d
  pinMode(6,OUTPUT); // segment e
  pinMode(7,OUTPUT); // segment f
  pinMode(8,OUTPUT); // segment g
  pinMode(9,OUTPUT); // decimal point of the seven segment display
  pinMode(10,OUTPUT); // common
  pinMode(11,OUTPUT); // LED 2
  pinMode(12,OUTPUT); // LED 3
  pinMode(13,OUTPUT); // LED 4
  
  /*                                       BEGIN AMANDA’s CODE 			*/
  cli();//disable interrupts
  
  //set up continuous sampling of analog pin 0 at 38.5kHz
 
  //clear ADCSRA and ADCSRB registers
  ADCSRA = 0;
  ADCSRB = 0;
  
  ADMUX |= (1 << REFS0); //set reference voltage
  ADMUX |= (1 << ADLAR); //left align the ADC value- so we can read highest 8 bits from ADCH register only
  
  ADCSRA |= (1 << ADPS2) | (1 << ADPS0); //set ADC clock with 32 prescaler- 16mHz/32=500kHz
  ADCSRA |= (1 << ADATE); //enable auto trigger
  ADCSRA |= (1 << ADIE); //enable interrupts when measurement complete
  ADCSRA |= (1 << ADEN); //enable ADC
  ADCSRA |= (1 << ADSC); //start ADC measurements
  
  sei();//enable interrupts
}</p><p>ISR(ADC_vect) {//when new ADC value ready
  
  prevData = newData;//store previous value
  newData = ADCH;//get value from A0
  if (prevData < 127 && newData >=127){//if increasing and crossing midpoint
    newSlope = newData - prevData;//calculate slope
    if (abs(newSlope-maxSlope) 9){
          reset();
        }
      }
    }
    else if (newSlope>maxSlope){//if new slope is much larger than max slope
      maxSlope = newSlope;
      time = 0;//reset clock
      noMatch = 0;
      index = 0;//reset index
    }
    else{//slope not steep enough
      noMatch++;//increment no match counter
      if (noMatch>9){
        reset();
      }
    }
  }
    
  time++;//increment timer at rate of 38.5kHz
  
  ampTimer++;//increment amplitude timer
  if (abs(127-ADCH)>maxAmp){
    maxAmp = abs(127-ADCH);
  }
  if (ampTimer==1000){
    ampTimer = 0;
    checkMaxAmp = maxAmp;
    maxAmp = 0;
  }
}</p><p>void reset(){//clear out some variables
  index = 0;//reset index
  noMatch = 0;//reset match counter
  maxSlope = 0;//reset slope
}</p><p>/*				END AMANDA’s CODE 					*/</p><p>void frequencyCheck(){
  
  if(frequency>70&&frequency<90){ // Displays E on the seven segment display and turns on two LEDs
    digitalWrite(2,HIGH);
    digitalWrite(5,HIGH);
    digitalWrite(6,HIGH);
    digitalWrite(7,HIGH);
    digitalWrite(8,HIGH);
    digitalWrite(10,LOW);
    digitalWrite(11,HIGH);
  }
  else if(frequency>100&&frequency<120){ // Displays A on the seven segment display and turns on two LEDs
    digitalWrite(2,HIGH);
    digitalWrite(3,HIGH);
    digitalWrite(4,HIGH);
    digitalWrite(6,HIGH);
    digitalWrite(7,HIGH);
    digitalWrite(8,HIGH);
    digitalWrite(10,LOW);
    digitalWrite(11,HIGH);
  }
  else if(frequency>135&&frequency<155){ // Displays D on the seven segment display and turns on three LEDs
    digitalWrite(3,HIGH);
    digitalWrite(4,HIGH);
    digitalWrite(5,HIGH);
    digitalWrite(6,HIGH);
    digitalWrite(8,HIGH);
    digitalWrite(10,LOW);
    digitalWrite(11,HIGH);
    digitalWrite(12,HIGH);
  }
  else if(frequency>186&&frequency<205){ // Displays G on the seven segment display and turns on three LEDs
    digitalWrite(2,HIGH);
    digitalWrite(3,HIGH);
    digitalWrite(4,HIGH);
    digitalWrite(5,HIGH);
    digitalWrite(7,HIGH);
    digitalWrite(8,HIGH);
    digitalWrite(10,LOW);
    digitalWrite(11,HIGH);
    digitalWrite(12,HIGH);
  }
  else if(frequency>235&&frequency<255){ // Displays B on the seven segment display and turns on three LEDs
    digitalWrite(4,HIGH);
    digitalWrite(5,HIGH);
    digitalWrite(6,HIGH);
    digitalWrite(7,HIGH);
    digitalWrite(8,HIGH);
    digitalWrite(10,LOW);
    digitalWrite(11,HIGH);
    digitalWrite(12,HIGH);
  }
  else if(frequency>320&&frequency<340){ // Displays E on the seven segment display and turns on four LEDs
    digitalWrite(2,HIGH);
    digitalWrite(5,HIGH);
    digitalWrite(6,HIGH);
    digitalWrite(7,HIGH);
    digitalWrite(8,HIGH);
    digitalWrite(10,LOW);
    digitalWrite(11,HIGH);
    digitalWrite(12,HIGH);
    digitalWrite(13,HIGH);
  }
  else{
    digitalWrite(8,HIGH);
  }
}
//
void allOff(){ // turn off each segment of the seven segment display and all of the LEDs
  digitalWrite(2,LOW);
  digitalWrite(3,LOW);
  digitalWrite(4,LOW);
  digitalWrite(5,LOW);
  digitalWrite(6,LOW);
  digitalWrite(7,LOW);
  digitalWrite(8,LOW);
  digitalWrite(9,LOW);
  digitalWrite(10,LOW);
  digitalWrite(11,LOW);
  digitalWrite(12,LOW);
  digitalW礼仪（13，低）；
 } 
无效loop() { </P > <P> alloff()；
 
如果（checkmaxamp > ampthreshold）{ 
频率= 38462 /浮（期）；//定时器周期计算频率利用率超过
 
串口打印（频率）；//打印结果显示
串口串口。println（HZ）；
 } 
 
 frequencycheck()；
 
延迟（1000）；//一秒的延迟

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Arduino的吉他音符检测器(2)

步骤4：步骤4：测试

步骤5：结论，来源，和附录