from machine import Pin
import time
r1 = Pin(21,Pin.OUT)
r2 = Pin(22,Pin.OUT)
r3 = Pin(23,Pin.OUT)
bzr = Pin(18,Pin.OUT)
while True:
if:
r1.on()
r2.off()
r3.off()
bzr.value()==1
time.sleep(0.5)
elif
r1.on()
r2.on()
r3.off()
bzr.value()==0
time.sleep(0.5)
elif
r1.on()
r2.on()
r3.on()
bzr.value()==1
time.sleep(0.5)
elif
r1.off()
r2.off()
r3.off()
bzr.value()==0
time.sleep(0.5)