Hello, I am a total newbie to rpi and python and I would like to use HC-SR04 ultrasonic sensor in my project. I understand how the sensor works, but cannot make it work properly. I want to have function called ping() that will be called from other function what is called in main.py and ping() should return new meassured distance every run. If I run my function separatly in while loop, it works, but otherwise not. My code:
Code:
import RPi.GPIO as GPIOimport timelast_distance = 0def do_something(): distance = ping() print(distance) return_this = [(1,2),(2,1)] return return_thisdef ping(): global last_distance GPIO.setmode(GPIO.BOARD) TRIG_PIN = 7 ECHO_PIN = 11 GPIO.setup(TRIG_PIN, GPIO.OUT) GPIO.setup(ECHO_PIN, GPIO.IN) pulse_start_time = 0 pulse_end_time = 0 try: GPIO.output(TRIG_PIN, GPIO.LOW) time.sleep(2E-6) GPIO.output(TRIG_PIN, GPIO.HIGH) time.sleep(10E-6) GPIO.output(TRIG_PIN, GPIO.LOW) while GPIO.input(ECHO_PIN) == 0: pass pulse_start_time = time.time() while GPIO.input(ECHO_PIN) == 1: pass pulse_end_time = time.time() pulse_duration = pulse_end_time - pulse_start_time distance = round(pulse_duration * 17150, 2) if distance > 300 or distance <= 0: distance = last_distance else: last_distance = distance return distance except Exception as e: print(f"Error in ping function: {e}") Statistics: Posted by mart1nek — Thu Dec 21, 2023 5:48 pm