int pin = A0;
int ledPin = 13;
int minSignal = 600;
bool stateUp = false;
bool lastState = false;
bool oneStep = false;
void setup() {
	pinMode(pin, INPUT);
	pinMode(ledPin, OUTPUT);
	Serial.begin(9600);
}
void loop() {
	int signal = analogRead(pin);
	if (signal > minSignal){
		stateUp = true;
	}
	else{
		stateUp = false;
	}
	if (lastState != stateUp && lastState == false){
	       oneStep = not oneStep;
	}
	else {
	}
	lastState = stateUp;
	Serial.println(oneStep);
	digitalWrite(ledPin, oneStep); //индикатор
}

сlass DataManager:
    def __init__(self):
        self.time = time
        self.currentTimeForLastRace = datetime.now()
        self.currentTime = self.time.time()
        self.speed = 0
        self.db = MySQLdb.connect(host="localhost", user="root", passwd="root", db="skirunner", charset='utf8')
        self.cursor = self.db.cursor()
        self.isGetLastRaceSpeeds = False
        self.dataLastRace = []
        self.lastRaceMinDate = datetime.now()
        self.value = 0
        self.lastValue = 0
        self.impulse = 0
        self.isRaceStart = False
        self.currentRaceId = -1
        self.currentDistanceId = -1
        self.currentProfileId = -1

    def getImpulse(self, value):
        self.impulse = 0

        if self.time.time() - self.currentTime > RESET_SPEED_TIME:
            self.speed = 0
        self.value = value
        if self.value != self.lastValue:
            time = self.time.time() - self.currentTime
            self.impulse = POWER_IMPULSE
            self.isRaceStart = True

            self.speed = STEP / time # метры в секунду
            self.currentTime = self.time.time()
            self.lastValue = self.value

        return  self.impulse

    def getLastRaceDistanceAtCurrentTime(self, raceId,currentTime):
        lastRaceDistance = 0
        dateFormat = "%Y-%m-%d %H:%M:%S.%f"
        if  not self.isGetLastRaceSpeeds:

            sql = """SELECT min(date) FROM runLog WHERE race_id = %s""" % raceId
            self.cursor.execute(sql)
            data = self.cursor.fetchall()
            for rec in data:
                self.lastRaceMinDate = datetime.strptime(rec[0],dateFormat)
            sql = """SELECT distance,date FROM runLog WHERE race_id = %s ORDER BY date DESC""" % raceId
            self.cursor.execute(sql)
            self.dataLastRace = self.cursor.fetchall()
            self.isGetLastRaceSpeeds = True

        if self.isRaceStart:
            time = datetime.now() - datetime.fromtimestamp(currentTime)
            for rec in self.dataLastRace:
                distance, date = rec
                if time <= (datetime.strptime(date,dateFormat) - self.lastRaceMinDate):
                    lastRaceDistance = distance
        return  lastRaceDistance

class FormProfile(QMainWindow):

    def __init__(self):
        super(QMainWindow, self).__init__()
        uic.loadUi('%s/ui/frm_profile.ui' % DIR, self)
        self.cb_profile_load()
        self.te_newProfile.hide()
        self.bt_addProfile.hide()
        self.bt_cancel.hide()
        self.lb_add.hide()
        self.move(QDesktopWidget().availableGeometry().center() - self.frameGeometry().center())

        self.connect(self.bt_ok, SIGNAL("clicked()"), self.bt_ok_clicked)
        self.connect(self.bt_new, SIGNAL("clicked()"), self.bt_new_clicked)
        self.connect(self.bt_addProfile,SIGNAL("clicked()"), self.bt_addProfile_clicked)
        self.connect(self.bt_cancel, SIGNAL("clicked()"), self.bt_cancel_clicked)
        self.connect(self.bt_graph, SIGNAL("clicked()"), self.bt_graph_clicked)

    def bt_ok_clicked(self):
        self.profileId = self.cb_profile.itemData(self.cb_profile.currentIndex()).toString()
        self.formDistance = FormDistance(self.profileId)
        self.formDistance.show()
        self.hide()

import matplotlib.pyplot as plt
    def bt_averageSpeed_clicked(self):
        ...
        plt.plot_date(dates, values,'b')
        plt.plot_date(dates, values,'bo')
        averageSpeed = len(values) > 0 and (lambda: sum(values) / len(values)) or (lambda: 0)
        plt.xlabel(u"Средняя-средняя скорость= %.2f м/с или %.2f км/ч" % (float(averageSpeed()),float(averageSpeed()) / 1000 * 3600))
        plt.ylabel(u"Средняя скорость (м/с)")
        plt.title(u"График скоростей профиля %s" % dm.getProfileNameById(self.profileId))
        plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%d/%m/%y'))
        plt.gcf().autofmt_xdate()
        plt.grid(True)
        plt.show()

from matplotlib import rc
   font = {'family': 'Droid Sans',
        'weight': 'normal',
        'size': 14}
        rc('font', **font)