对前几天的实验的扩展，用七段显示器显示计数，用的是官方的库SevSeg.h，

实验现象:  https://v.douyin.com/e5p2uGe/

代码

#include <MsTimer2.h>//加入计时器用来测量速度
#include "SevSeg.h"//引入七段显示器库
SevSeg sevseg;//构建七段显示器对象
#define DEBOUNCE_TIME 2 //延时用来过滤不正常的信号，数字越大闪烁越明显
// 定义引脚2.3
int APhase = 2;
int BPhase = 3;

long count = 0;//计数

 

long preverCount = 0;//上一次的计数
long cerrentCount = 0;//当前计数


void getSpeed(){   
  preverCount = cerrentCount;
  cerrentCount = count;
  Serial.println( "speed is " + String (cerrentCount - preverCount) ) ;

   
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(APhase, INPUT_PULLUP);
  pinMode(BPhase, INPUT_PULLUP);
  pinMode(LED_BUILTIN,OUTPUT);
  MsTimer2::set(1000, getSpeed);//改变计时时间可以调整速度的刷新率
  //开始计时
  MsTimer2::start();






  byte numDigits = 4;//四位七段式显示器
  byte digitPins[] = {4, 5, 6, 7};//每位数字的针脚
  byte segmentPins[] = {8, 9, 10, 11, 12, 13, A0, A1};//依顺序的针脚
  bool resistorsOnSegments = false; // 'false' means resistors are on digit pins
  byte hardwareConfig = COMMON_ANODE; // See README.md for options，共阳极
  bool updateWithDelays = false; // Default 'false' is Recommended
  bool leadingZeros = false; // Use 'true' if you'd like to keep the leading zeros
  bool disableDecPoint = false; // Use 'true' if your decimal point doesn't exist or isn't connected
  
  sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments,
  updateWithDelays, leadingZeros, disableDecPoint);
  sevseg.setBrightness(100);
  
}

void loop() {
  //put your main code here, to run repeatedly:
  
  
  int  firstAPhaseState= digitalRead(APhase);
  //digitalWrite(LED_BUILTIN,firstAPhaseState);
  if (firstAPhaseState == 1 ) {
    delay(DEBOUNCE_TIME);
    int secendAPhaseState  = digitalRead(APhase);
    
    //从1变成0 开始判断是正转还是反转
    if (secendAPhaseState  == 0) {
      //用B相信号判断正反转
      if (digitalRead(BPhase) == 0) {
      count++;
      Serial.println(count);
      
      }
      if (digitalRead(BPhase) == 1) {
      count--;
      Serial.println(count);
      
      }
    
    }
    
  }
    //初始状态是0的判断，想改进的话可以用外部中断的上升沿事件 
    if (firstAPhaseState == 0) {
    delay(DEBOUNCE_TIME);
    int secendAPhaseState = digitalRead(APhase);
    if (secendAPhaseState == 1) {
      
      if (digitalRead(BPhase) == 1) {
        count++;
        Serial.println(count);
        
        }
      if (digitalRead(BPhase) == 0) {
      count--;
      Serial.println(count);
      
      }
    }
   
  }
  sevseg.setNumber(count, 0);
  sevseg.refreshDisplay();//不刷新的话不亮灯
  
  
}