라즈베리파이 조도센서 설치 BH1750 (디지털출력가능)

1.  i2c 를 활성화한 상태에서 실행해야한다.

2. smbus 를 설치해야한다. 

sudo apt-get update

sudo apt-get install python-smbus

핀의 연결은 아래와 같다.

아래 코드를 실행

#!/usr/bin/python

import smbus

import time

 

# Define some constants from the datasheet

 

DEVICE     = 0x23 # Default device I2C address

 

POWER_DOWN = 0x00 # No active state

POWER_ON   = 0x01 # Power on

RESET      = 0x07 # Reset data register value

 

# Start measurement at 4lx resolution. Time typically 16ms.

CONTINUOUS_LOW_RES_MODE = 0x13

# Start measurement at 1lx resolution. Time typically 120ms

CONTINUOUS_HIGH_RES_MODE_1 = 0x10

# Start measurement at 0.5lx resolution. Time typically 120ms

CONTINUOUS_HIGH_RES_MODE_2 = 0x11

# Start measurement at 1lx resolution. Time typically 120ms

# Device is automatically set to Power Down after measurement.

ONE_TIME_HIGH_RES_MODE_1 = 0x20

# Start measurement at 0.5lx resolution. Time typically 120ms

# Device is automatically set to Power Down after measurement.

ONE_TIME_HIGH_RES_MODE_2 = 0x21

# Start measurement at 1lx resolution. Time typically 120ms

# Device is automatically set to Power Down after measurement.

ONE_TIME_LOW_RES_MODE = 0x23

 

#bus = smbus.SMBus(0) # Rev 1 Pi uses 0

bus = smbus.SMBus(1)  # Rev 2 Pi uses 1

 

def convertToNumber(data):

  # Simple function to convert 2 bytes of data

  # into a decimal number

  return ((data[1] + (256 * data[0])) / 1.2)

 

def readLight(addr=DEVICE):

  data = bus.read_i2c_block_data(addr,ONE_TIME_HIGH_RES_MODE_1)

  return convertToNumber(data)

 

def main():

 

  while True:

    print "Light Level : " + str(readLight()) + " lx"

    time.sleep(0.5)

   

if __name__=="__main__":

   main()

또는 웹사이트에서 바로 다운로드

wget https://bitbucket.org/MattHawkinsUK/rpispy-misc/raw/master/python/bh1750.py

설치 완료사진

테스트 화면

200ms 단위로 새로 측정하는데, Ctrl+C 키를 눌러서 강제 종료해야한다.