from machine import Pin,Timer
from time import sleep

clk = Pin(2,Pin.IN)   # clk
dt = Pin(3,Pin.IN)   # dt
count=20
def clk_change(clk):
    global count
    if dt.value()==1:
        count=count+1
    else:
        count=count-1
    print(count)

clk.irq(trigger=Pin.IRQ_FALLING, handler=clk_change)
while 1:
    #print(count)
    sleep(0.5)