Adafruit_BME280.py code:

# Copyright (c) 2014 Adafruit Industries # Author: Tony DiCola # # Based on the BMP280 driver with BME280 changes provided by # David J Taylor, Edinburgh (www.satsignal.eu). Additional functions added # by Tom Nardi (www.digifail.com) # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. import logging import time

# BME280 default address. BME280_I2CADDR = 0x77

# Operating Modes BME280_OSAMPLE_1 = 1 BME280_OSAMPLE_2 = 2 BME280_OSAMPLE_4 = 3 BME280_OSAMPLE_8 = 4 BME280_OSAMPLE_16 = 5

# Standby Settings BME280_STANDBY_0p5 = 0 BME280_STANDBY_62p5 = 1 BME280_STANDBY_125 = 2 BME280_STANDBY_250 = 3 BME280_STANDBY_500 = 4 BME280_STANDBY_1000 = 5 BME280_STANDBY_10 = 6 BME280_STANDBY_20 = 7

# Filter Settings BME280_FILTER_off = 0 BME280_FILTER_2 = 1 BME280_FILTER_4 = 2 BME280_FILTER_8 = 3 BME280_FILTER_16 = 4

# BME280 Registers

BME280_REGISTER_DIG_T1 = 0x88 # Trimming parameter registers BME280_REGISTER_DIG_T2 = 0x8A BME280_REGISTER_DIG_T3 = 0x8C

BME280_REGISTER_DIG_P1 = 0x8E BME280_REGISTER_DIG_P2 = 0x90 BME280_REGISTER_DIG_P3 = 0x92 BME280_REGISTER_DIG_P4 = 0x94 BME280_REGISTER_DIG_P5 = 0x96 BME280_REGISTER_DIG_P6 = 0x98 BME280_REGISTER_DIG_P7 = 0x9A BME280_REGISTER_DIG_P8 = 0x9C BME280_REGISTER_DIG_P9 = 0x9E

BME280_REGISTER_DIG_H1 = 0xA1 BME280_REGISTER_DIG_H2 = 0xE1 BME280_REGISTER_DIG_H3 = 0xE3 BME280_REGISTER_DIG_H4 = 0xE4 BME280_REGISTER_DIG_H5 = 0xE5 BME280_REGISTER_DIG_H6 = 0xE6 BME280_REGISTER_DIG_H7 = 0xE7

BME280_REGISTER_CHIPID = 0xD0 BME280_REGISTER_VERSION = 0xD1 BME280_REGISTER_SOFTRESET = 0xE0

BME280_REGISTER_STATUS = 0xF3 BME280_REGISTER_CONTROL_HUM = 0xF2 BME280_REGISTER_CONTROL = 0xF4 BME280_REGISTER_CONFIG = 0xF5 BME280_REGISTER_DATA = 0xF7

class BME280(object): def __init__(self, t_mode=BME280_OSAMPLE_1, p_mode=BME280_OSAMPLE_1, h_mode=BME280_OSAMPLE_1, standby=BME280_STANDBY_250, filter=BME280_FILTER_off, address=BME280_I2CADDR, i2c=None, **kwargs): self._logger = logging.getLogger('Adafruit_BMP.BMP085') # Check that t_mode is valid. if t_mode not in [BME280_OSAMPLE_1, BME280_OSAMPLE_2, BME280_OSAMPLE_4, BME280_OSAMPLE_8, BME280_OSAMPLE_16]: raise ValueError( 'Unexpected t_mode value {0}.'.format(t_mode)) self._t_mode = t_mode # Check that p_mode is valid. if p_mode not in [BME280_OSAMPLE_1, BME280_OSAMPLE_2, BME280_OSAMPLE_4, BME280_OSAMPLE_8, BME280_OSAMPLE_16]: raise ValueError( 'Unexpected p_mode value {0}.'.format(p_mode)) self._p_mode = p_mode # Check that h_mode is valid. if h_mode not in [BME280_OSAMPLE_1, BME280_OSAMPLE_2, BME280_OSAMPLE_4, BME280_OSAMPLE_8, BME280_OSAMPLE_16]: raise ValueError( 'Unexpected h_mode value {0}.'.format(h_mode)) self._h_mode = h_mode # Check that standby is valid. if standby not in [BME280_STANDBY_0p5, BME280_STANDBY_62p5, BME280_STANDBY_125, BME280_STANDBY_250, BME280_STANDBY_500, BME280_STANDBY_1000, BME280_STANDBY_10, BME280_STANDBY_20]: raise ValueError( 'Unexpected standby value {0}.'.format(standby)) self._standby = standby # Check that filter is valid. if filter not in [BME280_FILTER_off, BME280_FILTER_2, BME280_FILTER_4, BME280_FILTER_8, BME280_FILTER_16]: raise ValueError( 'Unexpected filter value {0}.'.format(filter)) self._filter = filter # Create I2C device. if i2c is None: import Adafruit_GPIO.I2C as I2C i2c = I2C # Create device, catch permission errors try: self._device = i2c.get_i2c_device(address, **kwargs) except IOError: print("Unable to communicate with sensor, check permissions.") exit() # Load calibration values. self._load_calibration() self._device.write8(BME280_REGISTER_CONTROL, 0x24) # Sleep mode time.sleep(0.002) self._device.write8(BME280_REGISTER_CONFIG, ((standby << 5) | (filter << 2))) time.sleep(0.002) self._device.write8(BME280_REGISTER_CONTROL_HUM, h_mode) # Set Humidity Oversample self._device.write8(BME280_REGISTER_CONTROL, ((t_mode << 5) | (p_mode << 2) | 3)) # Set Temp/Pressure Oversample and enter Normal mode self.t_fine = 0.0

def _load_calibration(self):

self.dig_T1 = self._device.readU16LE(BME280_REGISTER_DIG_T1) self.dig_T2 = self._device.readS16LE(BME280_REGISTER_DIG_T2) self.dig_T3 = self._device.readS16LE(BME280_REGISTER_DIG_T3)

self.dig_P1 = self._device.readU16LE(BME280_REGISTER_DIG_P1) self.dig_P2 = self._device.readS16LE(BME280_REGISTER_DIG_P2) self.dig_P3 = self._device.readS16LE(BME280_REGISTER_DIG_P3) self.dig_P4 = self._device.readS16LE(BME280_REGISTER_DIG_P4) self.dig_P5 = self._device.readS16LE(BME280_REGISTER_DIG_P5) self.dig_P6 = self._device.readS16LE(BME280_REGISTER_DIG_P6) self.dig_P7 = self._device.readS16LE(BME280_REGISTER_DIG_P7) self.dig_P8 = self._device.readS16LE(BME280_REGISTER_DIG_P8) self.dig_P9 = self._device.readS16LE(BME280_REGISTER_DIG_P9)

self.dig_H1 = self._device.readU8(BME280_REGISTER_DIG_H1) self.dig_H2 = self._device.readS16LE(BME280_REGISTER_DIG_H2) self.dig_H3 = self._device.readU8(BME280_REGISTER_DIG_H3) self.dig_H6 = self._device.readS8(BME280_REGISTER_DIG_H7)

h4 = self._device.readS8(BME280_REGISTER_DIG_H4) h4 = (h4 << 4) self.dig_H4 = h4 | (self._device.readU8(BME280_REGISTER_DIG_H5) & 0x0F)

h5 = self._device.readS8(BME280_REGISTER_DIG_H6) h5 = (h5 << 4) self.dig_H5 = h5 | ( self._device.readU8(BME280_REGISTER_DIG_H5) >> 4 & 0x0F)

''' print '0xE4 = {0:2x}'.format (self._device.readU8 (BME280_REGISTER_DIG_H4)) print '0xE5 = {0:2x}'.format (self._device.readU8 (BME280_REGISTER_DIG_H5)) print '0xE6 = {0:2x}'.format (self._device.readU8 (BME280_REGISTER_DIG_H6))

print 'dig_H1 = {0:d}'.format (self.dig_H1) print 'dig_H2 = {0:d}'.format (self.dig_H2) print 'dig_H3 = {0:d}'.format (self.dig_H3) print 'dig_H4 = {0:d}'.format (self.dig_H4) print 'dig_H5 = {0:d}'.format (self.dig_H5) print 'dig_H6 = {0:d}'.format (self.dig_H6) '''

def read_raw_temp(self): """Waits for reading to become available on device.""" """Does a single burst read of all data values from device.""" """Returns the raw (uncompensated) temperature from the sensor.""" while (self._device.readU8(BME280_REGISTER_STATUS) & 0x08): # Wait for conversion to complete (TODO : add timeout) time.sleep(0.002) self.BME280Data = self._device.readList(BME280_REGISTER_DATA, 8) raw = ((self.BME280Data[3] << 16) | (self.BME280Data[4] << 8) | self.BME280Data[5]) >> 4 return raw

def read_raw_pressure(self): """Returns the raw (uncompensated) pressure level from the sensor.""" """Assumes that the temperature has already been read """ """i.e. that BME280Data[] has been populated.""" raw = ((self.BME280Data[0] << 16) | (self.BME280Data[1] << 8) | self.BME280Data[2]) >> 4 return raw

def read_raw_humidity(self): """Returns the raw (uncompensated) humidity value from the sensor.""" """Assumes that the temperature has already been read """ """i.e. that BME280Data[] has been populated.""" raw = (self.BME280Data[6] << 8) | self.BME280Data[7] return raw

def read_temperature(self): """Gets the compensated temperature in degrees celsius.""" # float in Python is double precision UT = float(self.read_raw_temp()) var1 = (UT / 16384.0 - float(self.dig_T1) / 1024.0) * float(self.dig_T2) var2 = ((UT / 131072.0 - float(self.dig_T1) / 8192.0) * ( UT / 131072.0 - float(self.dig_T1) / 8192.0)) * float(self.dig_T3) self.t_fine = int(var1 + var2) temp = (var1 + var2) / 5120.0 return temp

def read_pressure(self): """Gets the compensated pressure in Pascals.""" adc = float(self.read_raw_pressure()) var1 = float(self.t_fine) / 2.0 - 64000.0 var2 = var1 * var1 * float(self.dig_P6) / 32768.0 var2 = var2 + var1 * float(self.dig_P5) * 2.0 var2 = var2 / 4.0 + float(self.dig_P4) * 65536.0 var1 = ( float(self.dig_P3) * var1 * var1 / 524288.0 + float(self.dig_P2) * var1) / 524288.0 var1 = (1.0 + var1 / 32768.0) * float(self.dig_P1) if var1 == 0: return 0 p = 1048576.0 - adc p = ((p - var2 / 4096.0) * 6250.0) / var1 var1 = float(self.dig_P9) * p * p / 2147483648.0 var2 = p * float(self.dig_P8) / 32768.0 p = p + (var1 + var2 + float(self.dig_P7)) / 16.0 return p

def read_humidity(self): adc = float(self.read_raw_humidity()) # print 'Raw humidity = {0:d}'.format (adc) h = float(self.t_fine) - 76800.0 h = (adc - (float(self.dig_H4) * 64.0 + float(self.dig_H5) / 16384.0 * h)) * ( float(self.dig_H2) / 65536.0 * (1.0 + float(self.dig_H6) / 67108864.0 * h * ( 1.0 + float(self.dig_H3) / 67108864.0 * h))) h = h * (1.0 - float(self.dig_H1) * h / 524288.0) if h > 100: h = 100 elif h < 0: h = 0 return h

def read_temperature_f(self): # Wrapper to get temp in F celsius = self.read_temperature() temp = celsius * 1.8 + 32 return temp

def read_pressure_inches(self): # Wrapper to get pressure in inches of Hg pascals = self.read_pressure() inches = pascals * 0.0002953 return inches

def read_dewpoint(self): # Return calculated dewpoint in C, only accurate at > 50% RH celsius = self.read_temperature() humidity = self.read_humidity() dewpoint = celsius - ((100 - humidity) / 5) return dewpoint

def read_dewpoint_f(self): # Return calculated dewpoint in F, only accurate at > 50% RH dewpoint_c = self.read_dewpoint() dewpoint_f = dewpoint_c * 1.8 + 32 return dewpoint_f

BME280_Example.py code:

from Adafruit_BME280 import *

sensor = BME280(t_mode=BME280_OSAMPLE_8, p_mode=BME280_OSAMPLE_8, h_mode=BME280_OSAMPLE_8)

degrees = sensor.read_temperature() pascals = sensor.read_pressure() hectopascals = pascals / 100 humidity = sensor.read_humidity()

print 'Temp = {0:0.3f} deg C'.format(degrees) print 'Pressure = {0:0.2f} hPa'.format(hectopascals) print 'Humidity = {0:0.2f} %'.format(humidity)

How can I modify this code so that my sensor can print out in farenheight instead of celcius?