I have an issue with ultrasonic Sensor using my Raspberry Pi 2W. The input pin is always zero. I tried to change pins, but nothing changed.

Here it is my sample code:

import RPi.GPIO as gp
import time
import signal
import sys


def handler(signum, frame):
    print('nPulizia gpio')
    time.sleep(0.5)
    gp.cleanup()
    sys.exit()

inputPin = 12 # connect to echo via 1K resistor
outputPin = 13 # connect to trig
led = 7

gp.setmode(gp.BOARD)
gp.setup(outputPin,gp.OUT)
gp.setup(inputPin,gp.IN)
gp.setup(led,gp.OUT)
signal.signal(signal.SIGTSTP, handler)
print(outputPin)
print(inputPin)

l = gp.output(led,True)

o = gp.output(outputPin,True)

time.sleep(0.001)
o2 = gp.output(outputPin,False)

time.sleep(0.5)
l = gp.output(led,False)
print("Inizio a calcolare l'echo...")
while gp.input(inputPin) == 0:
        start = time.time()
gp.output(led,True)
while gp.input(inputPin) == 1:
        stop = time.time()
gp.output(led,False)
currentTime = stop - start
distance = currentTime / 0.000058

print("Distance is " + str(distance) + " cm")

gp.cleanup() here

I don’t know what to to, i also used different sensors. Pins should work because i also tried a led and it turns on and off.