我正在尝试编写一个程序,以显示连接到Pi 3B +的超声波传感器的输出。代码“挂起”,我的意思是输出的显示突然停止并且程序不再响应。有人可以帮我指出我的代码中的错误吗?
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
TRIG = 16
ECHO = 18
GPIO.setup(TRIG,GPIO.OUT)
GPIO.setup(ECHO,GPIO.IN)
GPIO.output(TRIG, False)
try:
while True:
GPIO.output(TRIG, True)
time.sleep(0.00001)
GPIO.output(TRIG, False)
while GPIO.input(ECHO)==0:
pulse_start = time.time()
while GPIO.input(ECHO)==1:
pulse_end = time.time()
pulse_duration = pulse_end - pulse_start
distance = pulse_duration * 17150
distance = round(distance+1.15, 2)
if distance<=400 and distance>=5:
print "distance:",distance,"cm"
except KeyboardInterrupt:
GPIO.cleanup()
编辑:解决了这个问题,“尝试”和“除外”块可能是罪魁祸首,我删除了“尝试”块,现在我可以无限期地输出了。谢谢您的帮助。
答案 0 :(得分:0)
错误与代码的Try and Except块有关,如果板上的接收器未接收到任何回声输出,它将使try块失败并进入except块,在此我清除连接到Pi的所有引脚。这就是为什么代码会在一段时间后停止工作的原因,一旦未检测到回声,引脚就会被清除。删除try块可实现不间断的测距。代码应作如下修改:
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
TRIG = 16
ECHO = 18
GPIO.setup(TRIG,GPIO.OUT)
GPIO.setup(ECHO,GPIO.IN)
GPIO.output(TRIG, False)
while True:
GPIO.output(TRIG, True)
time.sleep(0.00001)
GPIO.output(TRIG, False)
while GPIO.input(ECHO)==0:
pulse_start = time.time()
while GPIO.input(ECHO)==1:
pulse_end = time.time()
pulse_duration = pulse_end - pulse_start
distance = pulse_duration * 17150
distance = round(distance+1.15, 2)
if distance<=400 and distance>=5:
print "distance:",distance,"cm"