#6 라즈베리파이 PIR 센서 (움직임 감지)

//

일시 : 2018.01.10 13:00 ~

내용 : PIR Sensor

//

PIR(Passive Infrared) sensor

• 물체에서 방출되거나 반사되는 적외선 파장의 움직임에 반응하는 센서

• 24번 핀을 input으로 설정하여 주기적으로 검사

실습

• 단순 움직임 감지 - 움직임을 감지하면 감지된 횟수를 출력

  import RPi.GPIO as GPIO
  import time
  ​
  GPIO.setmode(GPIO.BCM)
  ​
  pir = 24
  GPIO.setup(pir, GPIO.IN)
  ​
  def loop():
      cnt = 0
      while True:
          cur_stat = GPIO.input(pir)
          if cur_stat == 1:
              cnt += 1
              print("%d번 감지됨" % cnt)
          
  try :
      loop()
  except KeyboardInterrupt:
      pass
  finally:
      GPIO.cleanup()

• pir과 led연동 - 감지될 때마다 LED를 켜줌

  
  import RPi.GPIO as GPIO
  import time
  ​
  GPIO.setmode(GPIO.BCM)
  pir_pin = 24
  GPIO.setup(pir_pin, GPIO.IN)
  ​
  led_pin1 = 14
  led_pin2 = 15
  GPIO.setup(led_pin1, GPIO.OUT)
  GPIO.setup(led_pin2, GPIO.OUT)
  ​
  def loop():
      cnt = 0
      
      while True:
          if GPIO.input(pir_pin) == True:
              cnt += 1
              print("%d번 감지됨" % cnt)
              GPIO.output(led_pin1, True)
              GPIO.output(led_pin2, True)
              time.sleep(0.01)
          else:
              GPIO.output(led_pin1, False)
              GPIO.output(led_pin2, False)
              time.sleep(0.01)
      
  try :
      loop()
          
  except KeyboardInterrupt:
      pass
  finally:
      GPIO.cleanup()

• pir과 led연동 - 모듈 이용

  
  import RPi.GPIO as GPIO
  import time
  from led_pir import *
  ​
  GPIO.setmode(GPIO.BCM)
  ​
  pir = 24
  GPIO.setup(pir, GPIO.IN)
  ​
  def loop():
      cnt = 0
     
      while True:
          cur_stat = GPIO.input(pir)
          if cur_stat == 1:
              cnt += 1
              ledOn()
              print("%d번 감지됨" % cnt)
              time.sleep(0.3)
          elif cur_stat == 0:
              ledOff()
       
      
  try :
      loop()
  except KeyboardInterrupt:
      pass
  finally:
      GPIO.cleanup()

  
  ## led_pir.py
  import RPi.GPIO as GPIO
  import time
  ​
  GPIO.setmode(GPIO.BCM)
  ​
  led_pin1 = 14
  led_pin2 = 15
  ​
  GPIO.setup(led_pin1, GPIO.OUT)
  GPIO.setup(led_pin2, GPIO.OUT)
  ​
  def ledOn():
      GPIO.output(led_pin1, True)
      GPIO.output(led_pin2, True)
      time.sleep(1)
  ​
  def ledOff():
      GPIO.output(led_pin1, False)
      GPIO.output(led_pin2, False)

3초동안 led센서 유지하려면 time.sleep(3)

  while True:
          if GPIO.input(pir_pin) == True:
              cnt += 1
              print("%d번 감지됨" % cnt)
              GPIO.output(led_pin1, True)
              GPIO.output(led_pin2, True)
              time.sleep(3)
          GPIO.output(led_pin1, False)
          GPIO.output(led_pin2, False)

움직임 감지 뒤 3초동안 LED

   import RPi.GPIO as GPIO
  import time
  ​
  pir_pin=24
  led1=14
  led2=15
  ​
  GPIO.setmode(GPIO.BCM)
  GPIO.setup(pir_pin, GPIO.IN)
  GPIO.setup(led1, GPIO.OUT)
  GPIO.setup(led2, GPIO.OUT)
  ​
  def loop(cnt, time_check_cnt):
      
      cur_val=GPIO.input(pir_pin)
      if cur_val == True:
          cnt+=1
          print("감지됨 : %d" %cnt)
          GPIO.output(led1, True)
          GPIO.output(led2, True)
          time_check_cnt=0
      return cnt, time_check_cnt
      
  try:
      main_cnt=0
      cnt=0 
      time_check_cnt=0
      
      while True:
          main_cnt,time_check_cnt=loop(cnt, time_check_cnt)
          cnt=main_cnt
          time.sleep(0.1)
          time_check_cnt+=1
          if (time_check_cnt > 30):
              GPIO.output(led1, False)
              GPIO.output(led2, False)
              time_check_cnt=0
  ​
  except KeyboardInterrupt:
      pass
  finally:
      GPIO.cleanup()