#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// OLED FeatherWing buttons map to different pins depending on board.
// The I2C (Wire) bus may also be different.
#define WIRE Wire

Adafruit_SSD1306 display = Adafruit_SSD1306(128, 64, &WIRE);

int CLK = 2;//CLK->D2
int DT = 3;//DT->D3
const int interrupt0 = 0;// Interrupt 0 在 pin 2 上
int count = 5;//计数值
int lastCLK = 0;//CLK历史值

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // Address 0x3C for 128x32

  display.display();
  delay(1000);
  pinMode(CLK, INPUT);
  pinMode(DT, INPUT);
  attachInterrupt(interrupt0, ClockChanged, CHANGE);
  pinMode(4, INPUT);
  pinMode(5, OUTPUT);
}

void loop() {
  digitalRead(4);
  int sensorVal = digitalRead(4);

  if (sensorVal == HIGH){
    delay(2000);
    digitalWrite(5, HIGH);
    delay(5);
    digitalWrite(5, LOW);
    delay(10);
    digitalWrite(5, HIGH);
    delay(count);
    digitalWrite(5, LOW);
  }
    else{
    digitalWrite(5, LOW);
  }
  display.clearDisplay();
  display.display();
  display.setTextSize(4);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(40,18);
  display.print(count);
  display.setCursor(0,0);
  display.display(); // actually display all of the above
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(90,25);
  display.print("ms");
  display.setCursor(0,0);
  display.display(); // actually display all of the above
}
void ClockChanged()
{
  int clkValue = digitalRead(CLK);//读取CLK引脚的电平
  int dtValue = digitalRead(DT);//读取DT引脚的电平
  if (lastCLK != clkValue)
  {
    lastCLK = clkValue;
    count += (clkValue != dtValue ? 1 : -1);//CLK和DT不一致时+1，否则-1
     Serial.print("count:");
     Serial.println(count);
   }
  
}