def calculateMean(array: List[any]):
    global mean_
    mean_ = 0
    for index in range(len(list2)):
        mean_ = mean_ + list2.shift()
    mean_ = mean_ / 10
    return mean_
mean = 0
pulse = 0
mean_ = 0
list2: List[number] = []
serial.redirect_to_usb()
music.set_tempo(400)
list2 = []
wasBeatDetected = False
prevMean = 0

def on_forever():
    global list2, pulse, mean, wasBeatDetected, prevMean
    list2 = []
    for index2 in range(10):
        pulse = pins.analog_read_pin(AnalogReadWritePin.P1)
        list2.append(pulse)
        basic.pause(1)
    mean = calculateMean(list2)
    serial.write_value("pulse/2", pulse / 2)
    if pulse / 2 > mean and mean > prevMean:
        serial.write_value("beat", 1)
        if wasBeatDetected == False:
            basic.show_icon(IconNames.HEART)
            wasBeatDetected = True
    else:
        serial.write_value("beat", 0)
        if wasBeatDetected == True:
            basic.clear_screen()
            wasBeatDetected = False
    prevMean = mean
basic.forever(on_forever)