42 lines
1.3 KiB
Python
42 lines
1.3 KiB
Python
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import RPi.GPIO as GPIO
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import time
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GPIO.setmode( GPIO.BCM )
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GPIO.setwarnings( 0 )
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print( "sr04 print" )
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sr04_trig = 10
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sr04_echo = 11
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GPIO.setup( sr04_trig, GPIO.OUT )
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GPIO.setup( sr04_echo, GPIO.IN, pull_up_down=GPIO.PUD_DOWN )
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def sr04( trig_pin, echo_pin ):
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"""
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Return the distance in cm as measured by an SR04
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that is connected to the trig_pin and the echo_pin.
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These pins must have been configured as output and input.s
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"""
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GPIO.output(trig_pin, False) # altijd met false starten
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time.sleep(0.5)
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GPIO.output(trig_pin, True)
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time.sleep(0.00001) # pulse trigger
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GPIO.output(trig_pin, False)
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while GPIO.input(echo_pin) == False:
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start_time = time.time() # tijd opslaan wanneer de echo false is
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while GPIO.input(echo_pin) == True:
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end_time = time.time() # tijd opslaan wanneer de echo true is
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total_time = end_time - start_time # totaal aantal afstand in seconden
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return (round(total_time*34300/2, 2), total_time) #tuple terug geven met afstand in cm en totaal aantal seconden
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# sensor is niet helemaal naukeurig(~1-2cm variatie), kan ook aan de rpi timing liggen
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try:
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while True:
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print( sr04( sr04_trig, sr04_echo ))
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time.sleep( 0.5 )
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except KeyboardInterrupt:
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GPIO.cleanup()
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