from machine import Pin
from utime import sleep

led=Pin(0,Pin.OUT)
Faster=Pin(7,Pin.IN,Pin.PULL_UP)
Slower=Pin(8,Pin.IN,Pin.PULL_UP)
dly=1.0

def Flash_faster(Faster):
    global dly
    dly=dly-0.1

def Flash_slower(Slower):
    global dly
    dly=dly+0.1

Faster.irq(handler=Flash_faster,trigger=Faster.IRQ_FALLING) 
Slower.irq(handler=Flash_slower,trigger=Slower.IRQ_FALLING)

while True:
    led.value(1)
    sleep(dly)
    led.value(0)
    sleep(dly)