from machine import Pin
import time

N = 0

pin1 = Pin(15,Pin.IN,Pin.PULL_UP)
pin2 = Pin(14,Pin.IN,Pin.PULL_UP)

def ChA(pin1):
    global N
    if(pin1.value() == pin2.value()):
        N -= 1
    else:
        N += 1

def ChB(pin2):
    global N
    if(pin1.value() == pin2.value()):
        N += 1
    else:
        N -= 1

pin1.irq(trigger=Pin.IRQ_FALLING | Pin.IRQ_RISING, handler=ChA)
pin2.irq(trigger=Pin.IRQ_FALLING | Pin.IRQ_RISING, handler=ChB)

while (1):
    print(N)
    time.sleep_ms(100)