크래피의 박수를 계산해 보았습니다.

int analogPin = 3;     // potentiometer wiper (middle terminal) connected to analog pin 3
                       // outside leads to ground and +5V
int val = 0;           // variable to store the value read
int count = 0;
int clap = 0;
int preclap = 0;
int clapcount = 0;
void setup()
{
  Serial.begin(9600);          //  setup serial
}

void loop()
{
  val = analogRead(analogPin);    // read the input pin
  //Serial.println(val);
  if(val > 50){
    count++;
    clap = 1;
    //Serial.println("ON");
  }else{
    clap = 0;
    //Serial.println("OFF");
  }
  if(preclap == 1 && clap == 0 && count > 500) {
    clapcount++;
    //Serial.println(clapcount);
    Serial.println("8");
    count = 0;
  }
  preclap = clap;
}

from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
import sys
import serial
import serial.tools.list_ports
import re

# TODO
# Reset Button
# Close Serial
class ClappyCount(QWidget):

    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.ser = serial.Serial()
        self.ser.baudrate = 9600
        # print(list(serial.tools.list_ports.comports())[0][0])
        # self.ser.port = list(serial.tools.list_ports.comports())[0][0]
        self.ser.port = "COM7"
        self.ser.open()

        self.LCDDisplay = QLCDNumber(self)
        BoxLay = QVBoxLayout()
        BoxLay.addWidget(self.LCDDisplay)
        self.setLayout(BoxLay)
        self.setGeometry(500, 500, 300, 200)
        self.setWindowTitle('パチパチ数')
        self.clapcount = 0
        self.LCDDisplay.display(self.clapcount)
        self.show()
        self.showMaximized()
        timer = QTimer(self)
        timer.timeout.connect(self.Update)
        timer.start(100)

    def Update(self):
        self.buf = self.ser.readline()
        if self.buf != "":
            # self.clapcount = int(self.buf.decode('utf-8'))
            self.clapcount += 1;
        self.LCDDisplay.display(self.clapcount)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    win = ClappyCount()
    sys.exit(app.exec_())