CE_PYTHON_LIB/MAX44009.py at master · ControlEverythingCommunity/CE_PYTHON_LIB · GitHub

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# Distributed with a free-will license.
# Use it any way you want, profit or free, provided it fits in the licenses of its associated works.
# MAX44009
# This code is designed to work with the MAX44009_I2CS I2C Mini Module available from ControlEverything.com.
# https://www.controleverything.com/products

import smbus
import time

# Get I2C bus
bus = smbus.SMBus(1)

# I2C address of the device
MAX44009_DEFAULT_ADDRESS				= 0x4A

# MAX44009 Register Map
MAX44009_REG_INTR_STATUS				= 0x00 # Interrupt Status Register
MAX44009_REG_INTR_ENABLE				= 0x01 # Interrupt Enable Register
MAX44009_REG_CONFIG						= 0x02 # Configuration Register
MAX44009_REG_LUX_HIGH					= 0x03 # Lux High Byte
MAX44009_REG_LUX_LOW					= 0x04 # Lux Low Byte
MAX44009_REG_THRES_UP_HI				= 0x05 # Upper Threshold High Byte
MAX44009_REG_THRES_LO_HI				= 0x06 # Upper Threshold Low Byte
MAX44009_REG_THRES_TIMER				= 0x07 # Threshold Timer

# MAX44009 INTERRUPT ENABLE REGISTER
MAX44009_REG_INTR_ENABLE_NO_ASSRT		= 0x00 # The INT pin and the INTS bit are not asserted even if an interrupt event has occurred
MAX44009_REG_INTR_ENABLE_TRIGGER		= 0x01 # Detection of an interrupt event triggers a hardware interrupt

# MAX44009 CONFIGURATION REGISTER
MAX44009_REG_CONFIG_CONTMODE_DEFAULT	= 0x00 # Default mode
MAX44009_REG_CONFIG_CONTMODE_CONTIN		= 0x80 # Continuous mode
MAX44009_REG_CONFIG_MANUAL_DEFAULT		= 0x00 # Default mode of configuration is used for the IC
MAX44009_REG_CONFIG_MANUAL_MODEON		= 0x40 # Manual mode of configuration is used for the IC
MAX44009_REG_CONFIG_CDR_NODIVIDED		= 0x00 # Current not divided. All of the photodiode current goes to the ADC
MAX44009_REG_CONFIG_CDR_DIVIDED			= 0x08 # Current divided by 8
MAX44009_REG_CONFIG_INTRTIMER_800		= 0x00 # Integration Time = 800ms, This is a preferred mode for boosting low-light sensitivity
MAX44009_REG_CONFIG_INTRTIMER_400		= 0x01 # Integration Time = 400ms
MAX44009_REG_CONFIG_INTRTIMER_200		= 0x02 # Integration Time = 200ms
MAX44009_REG_CONFIG_INTRTIMER_100		= 0x03 # Integration Time = 100ms, This is a preferred mode for high-brightness applications
MAX44009_REG_CONFIG_INTRTIMER_50		= 0x04 # Integration Time = 50ms, Manual Mode only
MAX44009_REG_CONFIG_INTRTIMER_25		= 0x05 # Integration Time = 25ms, Manual Mode only
MAX44009_REG_CONFIG_INTRTIMER_12_5		= 0x06 # Integration Time = 12.5ms, Manual Mode only
MAX44009_REG_CONFIG_INTRTIMER_6_25		= 0x07 # Integration Time = 6.25ms, Manual Mode only

class MAX44009():
	def __init__(self):
		self.write_config()

	def write_config(self):
		"""Select the configuration register data from the given provided values"""
		CONFIG = (MAX44009_REG_CONFIG_CONTMODE_CONTIN | MAX44009_REG_CONFIG_MANUAL_MODEON | MAX44009_REG_CONFIG_CDR_NODIVIDED | MAX44009_REG_CONFIG_INTRTIMER_800)
		bus.write_byte_data(MAX44009_DEFAULT_ADDRESS, MAX44009_REG_CONFIG, CONFIG)

	def read_lumninance(self):
		"""Read data back from MAX44009_REG_LUX_HIGH(0x03), 2 bytes, luminance MSB, luminance LSB"""
		data = bus.read_i2c_block_data(MAX44009_DEFAULT_ADDRESS, MAX44009_REG_LUX_HIGH, 2)

		# Convert the data to lux
		exponent = (data[0] & 0xF0) >> 4
		mantissa = ((data[0] & 0x0F) << 4) | (data[1] & 0x0F)
		luminance = ((2 ** exponent) * mantissa) * 0.045

		return {'l' : luminance}

from MAX44009 import MAX44009
max44009 = MAX44009()

while True:
	lum = max44009.read_lumninance()
	print "Ambient Light luminance : %d lux" %(lum['l'])
	print " ***************************************** "
	time.sleep(0.5)