# https://wokwi.com/projects/397606153394832385
import time
time.sleep(0.1) # Wait for USB to become ready
print("Hello, Pi Pico!")
time.sleep(1)

import rp2
from machine import Pin
from rp2 import PIO
# ----- #
# echo1 #
# ----- #

@rp2.asm_pio(out_init=[PIO.OUT_LOW, PIO.OUT_HIGH])
def echo1():
    mov(y, null)
    wrap_target()
    pull(block)                           # 
    mov(pins, y)                          #    
    mov(y, invert(y))                     # 
    wrap()

sm0 = rp2.StateMachine(0, echo1, freq=2000, out_base=Pin(2))
sm0.active(1)


# >>> sm0.put(1)