Everything was done before
This commit is contained in:
commit
85d4b4f2cb
4 changed files with 418 additions and 0 deletions
236
bme280.py
Normal file
236
bme280.py
Normal file
|
|
@ -0,0 +1,236 @@
|
|||
# Authors: Paul Cunnane 2016, Peter Dahlebrg 2016
|
||||
#
|
||||
# This module borrows from the Adafruit BME280 Python library. Original
|
||||
# Copyright notices are reproduced below.
|
||||
#
|
||||
# Those libraries were written for the Raspberry Pi. This modification is
|
||||
# intended for the MicroPython and esp8266 boards.
|
||||
#
|
||||
# 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)
|
||||
#
|
||||
# Based on Adafruit_I2C.py created by Kevin Townsend.
|
||||
#
|
||||
# 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 time
|
||||
from ustruct import unpack, unpack_from
|
||||
from array import array
|
||||
|
||||
# BME280 default address.
|
||||
BME280_I2CADDR = 0x76
|
||||
|
||||
# Operating Modes
|
||||
BME280_OSAMPLE_1 = 1
|
||||
BME280_OSAMPLE_2 = 2
|
||||
BME280_OSAMPLE_4 = 3
|
||||
BME280_OSAMPLE_8 = 4
|
||||
BME280_OSAMPLE_16 = 5
|
||||
|
||||
BME280_REGISTER_CONTROL_HUM = 0xF2
|
||||
BME280_REGISTER_CONTROL = 0xF4
|
||||
|
||||
|
||||
class BME280:
|
||||
def __init__(
|
||||
self, mode=BME280_OSAMPLE_1, address=BME280_I2CADDR, i2c=None, **kwargs
|
||||
):
|
||||
# Check that mode is valid.
|
||||
if mode not in [
|
||||
BME280_OSAMPLE_1,
|
||||
BME280_OSAMPLE_2,
|
||||
BME280_OSAMPLE_4,
|
||||
BME280_OSAMPLE_8,
|
||||
BME280_OSAMPLE_16,
|
||||
]:
|
||||
raise ValueError(
|
||||
"Unexpected mode value {0}. Set mode to one of "
|
||||
"BME280_ULTRALOWPOWER, BME280_STANDARD, BME280_HIGHRES, or "
|
||||
"BME280_ULTRAHIGHRES".format(mode)
|
||||
)
|
||||
self._mode = mode
|
||||
self.address = address
|
||||
if i2c is None:
|
||||
raise ValueError("An I2C object is required.")
|
||||
self.i2c = i2c
|
||||
|
||||
# load calibration data
|
||||
dig_88_a1 = self.i2c.readfrom_mem(self.address, 0x88, 26)
|
||||
dig_e1_e7 = self.i2c.readfrom_mem(self.address, 0xE1, 7)
|
||||
(
|
||||
self.dig_T1,
|
||||
self.dig_T2,
|
||||
self.dig_T3,
|
||||
self.dig_P1,
|
||||
self.dig_P2,
|
||||
self.dig_P3,
|
||||
self.dig_P4,
|
||||
self.dig_P5,
|
||||
self.dig_P6,
|
||||
self.dig_P7,
|
||||
self.dig_P8,
|
||||
self.dig_P9,
|
||||
_,
|
||||
self.dig_H1,
|
||||
) = unpack("<HhhHhhhhhhhhBB", dig_88_a1)
|
||||
|
||||
self.dig_H2, self.dig_H3 = unpack("<hB", dig_e1_e7)
|
||||
e4_sign = unpack_from("<b", dig_e1_e7, 3)[0]
|
||||
self.dig_H4 = (e4_sign << 4) | (dig_e1_e7[4] & 0xF)
|
||||
|
||||
e6_sign = unpack_from("<b", dig_e1_e7, 5)[0]
|
||||
self.dig_H5 = (e6_sign << 4) | (dig_e1_e7[4] >> 4)
|
||||
|
||||
self.dig_H6 = unpack_from("<b", dig_e1_e7, 6)[0]
|
||||
|
||||
self.i2c.writeto_mem(self.address, BME280_REGISTER_CONTROL, bytearray([0x3F]))
|
||||
self.t_fine = 0
|
||||
|
||||
# temporary data holders which stay allocated
|
||||
self._l1_barray = bytearray(1)
|
||||
self._l8_barray = bytearray(8)
|
||||
self._l3_resultarray = array("i", [0, 0, 0])
|
||||
|
||||
def read_raw_data(self, result):
|
||||
"""Reads the raw (uncompensated) data from the sensor.
|
||||
|
||||
Args:
|
||||
result: array of length 3 or alike where the result will be
|
||||
stored, in temperature, pressure, humidity order
|
||||
Returns:
|
||||
None
|
||||
"""
|
||||
|
||||
self._l1_barray[0] = self._mode
|
||||
self.i2c.writeto_mem(self.address, BME280_REGISTER_CONTROL_HUM, self._l1_barray)
|
||||
self._l1_barray[0] = self._mode << 5 | self._mode << 2 | 1
|
||||
self.i2c.writeto_mem(self.address, BME280_REGISTER_CONTROL, self._l1_barray)
|
||||
|
||||
sleep_time = 1250 + 2300 * (1 << self._mode)
|
||||
sleep_time = sleep_time + 2300 * (1 << self._mode) + 575
|
||||
sleep_time = sleep_time + 2300 * (1 << self._mode) + 575
|
||||
time.sleep_us(sleep_time) # Wait the required time
|
||||
|
||||
# burst readout from 0xF7 to 0xFE, recommended by datasheet
|
||||
self.i2c.readfrom_mem_into(self.address, 0xF7, self._l8_barray)
|
||||
readout = self._l8_barray
|
||||
# pressure(0xF7): ((msb << 16) | (lsb << 8) | xlsb) >> 4
|
||||
raw_press = ((readout[0] << 16) | (readout[1] << 8) | readout[2]) >> 4
|
||||
# temperature(0xFA): ((msb << 16) | (lsb << 8) | xlsb) >> 4
|
||||
raw_temp = ((readout[3] << 16) | (readout[4] << 8) | readout[5]) >> 4
|
||||
# humidity(0xFD): (msb << 8) | lsb
|
||||
raw_hum = (readout[6] << 8) | readout[7]
|
||||
|
||||
result[0] = raw_temp
|
||||
result[1] = raw_press
|
||||
result[2] = raw_hum
|
||||
|
||||
def read_compensated_data(self, result=None):
|
||||
"""Reads the data from the sensor and returns the compensated data.
|
||||
|
||||
Args:
|
||||
result: array of length 3 or alike where the result will be
|
||||
stored, in temperature, pressure, humidity order. You may use
|
||||
this to read out the sensor without allocating heap memory
|
||||
|
||||
Returns:
|
||||
array with temperature, pressure, humidity. Will be the one from
|
||||
the result parameter if not None
|
||||
"""
|
||||
self.read_raw_data(self._l3_resultarray)
|
||||
raw_temp, raw_press, raw_hum = self._l3_resultarray
|
||||
# temperature
|
||||
var1 = ((raw_temp >> 3) - (self.dig_T1 << 1)) * (self.dig_T2 >> 11)
|
||||
var2 = (
|
||||
((((raw_temp >> 4) - self.dig_T1) * ((raw_temp >> 4) - self.dig_T1)) >> 12)
|
||||
* self.dig_T3
|
||||
) >> 14
|
||||
self.t_fine = var1 + var2
|
||||
temp = (self.t_fine * 5 + 128) >> 8
|
||||
|
||||
# pressure
|
||||
var1 = self.t_fine - 128000
|
||||
var2 = var1 * var1 * self.dig_P6
|
||||
var2 = var2 + ((var1 * self.dig_P5) << 17)
|
||||
var2 = var2 + (self.dig_P4 << 35)
|
||||
var1 = ((var1 * var1 * self.dig_P3) >> 8) + ((var1 * self.dig_P2) << 12)
|
||||
var1 = (((1 << 47) + var1) * self.dig_P1) >> 33
|
||||
if var1 == 0:
|
||||
pressure = 0
|
||||
else:
|
||||
p = 1048576 - raw_press
|
||||
p = (((p << 31) - var2) * 3125) // var1
|
||||
var1 = (self.dig_P9 * (p >> 13) * (p >> 13)) >> 25
|
||||
var2 = (self.dig_P8 * p) >> 19
|
||||
pressure = ((p + var1 + var2) >> 8) + (self.dig_P7 << 4)
|
||||
|
||||
# humidity
|
||||
h = self.t_fine - 76800
|
||||
h = (
|
||||
(((raw_hum << 14) - (self.dig_H4 << 20) - (self.dig_H5 * h)) + 16384) >> 15
|
||||
) * (
|
||||
(
|
||||
(
|
||||
(
|
||||
(
|
||||
((h * self.dig_H6) >> 10)
|
||||
* (((h * self.dig_H3) >> 11) + 32768)
|
||||
)
|
||||
>> 10
|
||||
)
|
||||
+ 2097152
|
||||
)
|
||||
* self.dig_H2
|
||||
+ 8192
|
||||
)
|
||||
>> 14
|
||||
)
|
||||
h = h - (((((h >> 15) * (h >> 15)) >> 7) * self.dig_H1) >> 4)
|
||||
h = 0 if h < 0 else h
|
||||
h = 419430400 if h > 419430400 else h
|
||||
humidity = h >> 12
|
||||
|
||||
if result:
|
||||
result[0] = temp
|
||||
result[1] = pressure
|
||||
result[2] = humidity
|
||||
return result
|
||||
|
||||
return array("i", (temp, pressure, humidity))
|
||||
|
||||
@property
|
||||
def values(self):
|
||||
"""human readable values"""
|
||||
|
||||
t, p, h = self.read_compensated_data()
|
||||
|
||||
p = p // 256
|
||||
pi = p // 100
|
||||
pd = p - pi * 100
|
||||
|
||||
hi = h // 1024
|
||||
hd = h * 100 // 1024 - hi * 100
|
||||
return (
|
||||
"{}C".format(t / 100),
|
||||
"{}.{:02d}hPa".format(pi, pd),
|
||||
"{}.{:02d}%".format(hi, hd),
|
||||
)
|
||||
Loading…
Add table
Add a link
Reference in a new issue