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python-bme680
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This commit is contained in:
Phil Howard 2017-10-17 12:28:06 +01:00
parent 2e7d805e62
commit f6bc4907c4
3 changed files with 120 additions and 38 deletions
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149
bme680/__init__.py
View File

@ -1,15 +1,23 @@
from .constants import *
import math
import smbus
import time
class BME680(BME680Data):
"""BOSCH BME680
Gas, pressure, temperature and humidity sensor.
:param i2c_addr: One of I2C_ADDR_PRIMARY (0x76) or I2C_ADDR_SECONDARY (0x77)
:param i2c_device: Optional smbus or compatible instance for facilitating i2c communications.
"""
def __init__(self, i2c_addr=I2C_ADDR_PRIMARY, i2c_device=None):
BME680Data.__init__(self)
self.i2c_addr = i2c_addr
self._i2c = i2c_device
if self._i2c is None:
import smbus
self._i2c = smbus.SMBus(1)
self.chip_id = self._get_regs(CHIP_ID_ADDR, 1)
@ -47,81 +55,152 @@ class BME680(BME680Data):
time.sleep(RESET_PERIOD / 1000.0)
def set_humidity_oversample(self, value):
"""Set humidity oversampling"""
"""Set humidity oversampling
A higher oversampling value means more stable sensor readings,
with less noise and jitter.
However each step of oversampling adds about 2ms to the latency,
causing a slower response time to fast transients.
:param value: Oversampling value, one of: OS_NONE, OS_1X, OS_2X, OS_4X, OS_8X, OS_16X
"""
self.tph_settings.os_hum = value
self._set_bits(CONF_OS_H_ADDR, OSH_MSK, OSH_POS, value)
#temp = self._get_regs(CONF_OS_H_ADDR, 1)
#temp &= ~OSH_MSK
#temp |= value << OSH_POS
#self._set_regs(CONF_OS_H_ADDR, temp)
def get_humidity_oversample(self):
"""Get humidity oversampling"""
return (self._get_regs(CONF_OS_H_ADDR, 1) & OSH_MSK) >> OSH_POS
def set_pressure_oversample(self, value):
"""Set temperature oversampling"""
"""Set temperature oversampling
A higher oversampling value means more stable sensor readings,
with less noise and jitter.
However each step of oversampling adds about 2ms to the latency,
causing a slower response time to fast transients.
:param value: Oversampling value, one of: OS_NONE, OS_1X, OS_2X, OS_4X, OS_8X, OS_16X
"""
self.tph_settings.os_pres = value
self._set_bits(CONF_T_P_MODE_ADDR, OSP_MSK, OSP_POS, value)
#temp = self._get_regs(CONF_T_P_MODE_ADDR, 1)
#temp &= ~OSP_MSK
#temp |= value << OSP_POS
#self._set_regs(CONF_T_P_MODE_ADDR, temp)
def get_pressure_oversample(self):
"""Get pressure oversampling"""
return (self._get_regs(CONF_T_P_MODE_ADDR, 1) & OSP_MSK) >> OSP_POS
def set_temperature_oversample(self, value):
"""Set pressure oversampling"""
"""Set pressure oversampling
A higher oversampling value means more stable sensor readings,
with less noise and jitter.
However each step of oversampling adds about 2ms to the latency,
causing a slower response time to fast transients.
:param value: Oversampling value, one of: OS_NONE, OS_1X, OS_2X, OS_4X, OS_8X, OS_16X
"""
self.tph_settings.os_temp = value
self._set_bits(CONF_T_P_MODE_ADDR, OST_MSK, OST_POS, value)
#temp = self._get_regs(CONF_T_P_MODE_ADDR, 1)
#temp &= ~OST_MSK
#temp |= value << OST_POS
#self._set_regs(CONF_T_P_MODE_ADDR, temp)
def get_temperature_oversample(self):
"""Get temperature oversampling"""
return (self._get_regs(CONF_T_P_MODE_ADDR, 1) & OST_MSK) >> OST_POS
def set_filter(self, value):
"""Set filter size"""
"""Set IIR filter size
Optionally remove short term fluctuations from the temperature and pressure readings,
increasing their resolution but reducing their bandwidth.
Enabling the IIR filter does not slow down the time a reading takes, but will slow
down the BME680s response to changes in temperature and pressure.
When the IIR filter is enabled, the temperature and pressure resolution is effectively 20bit.
When it is disabled, it is 16bit + oversampling-1 bits.
"""
self.tph_settings.filter = value
self._set_bits(CONF_ODR_FILT_ADDR, FILTER_MSK, FILTER_POS, value)
#temp = self._get_regs(CONF_ODR_FILT_ADDR, 1)
#temp &= ~FILTER_MSK
#temp |= value << FILTER_POS
#self._set_regs(CONF_ODR_FILT_ADDR, temp)
def get_filter(self):
"""Get filter size"""
return (self._get_regs(CONF_ODR_FILT_ADDR, 1) & FILTER_MSK) >> FILTER_POS
def select_gas_heater_profile(self, value):
"""Set current gas sensor conversion profile: 0 to 9
Select one of the 10 configured heating durations/set points.
"""
if value > NBCONV_MAX or value < NBCONV_MIN:
raise ValueError("Profile '{}' should be between {} and {}".format(value, NBCONV_MIN, NBCONV_MAX))
self.gas_settings.nb_conv = value
self._set_bits(CONF_ODR_RUN_GAS_NBC_ADDR, NBCONV_MSK, NBCONV_POS, value)
def get_gas_heater_profile(self):
"""Get gas sensor conversion profile: 0 to 9"""
return self._get_regs(CONF_ODR_RUN_GAS_NBC_ADDR, 1) & NBCONV_MSK
def set_gas_status(self, value):
"""Enable/disable gas sensor"""
self.gas_settings.run_gas = value
self._set_bits(CONF_ODR_RUN_GAS_NBC_ADDR, RUN_GAS_MSK, RUN_GAS_POS, value)
#temp = self._get_regs(CONF_ODR_RUN_GAS_NBC_ADDR, 1)
#temp &= ~RUN_GAS_MSK
#temp |= (value << RUN_GAS_POS)
#self._set_regs(CONF_ODR_RUN_GAS_NBC_ADDR, temp)
def get_gas_status(self):
"""Get the current gas status"""
return (self._get_regs(CONF_ODR_RUN_GAS_NBC_ADDR, 1) & RUN_GAS_MSK) >> RUN_GAS_POS
def set_gas_heater_temperature(self, value):
"""Set gas sensor heater temperature"""
def set_gas_heater_profile(self, temperature, duration, nb_profile=0):
"""Set temperature and duration of gas sensor heater
:param temperature: Target temperature in degrees celsius, between 200 and 400
:param durarion: Target duration in milliseconds, between 1 and 4032
:param nb_profile: Target profile, between 0 and 9
"""
self.set_gas_heater_temperature(temperature, nb_profile=nb_profile)
self.set_gas_heater_duration(duration, nb_profile=nb_profile)
def set_gas_heater_temperature(self, value, nb_profile=0):
"""Set gas sensor heater temperature
:param value: Target temperature in degrees celsius, between 200 and 400
When setting an nb_profile other than 0,
make sure to select it with select_gas_heater_profile.
"""
if nb_profile > NBCONV_MAX or value < NBCONV_MIN:
raise ValueError("Profile '{}' should be between {} and {}".format(nb_profile, NBCONV_MIN, NBCONV_MAX))
self.gas_settings.heatr_temp = value
temp = self._calc_heater_resistance(self.gas_settings.heatr_temp)
self._set_regs(RES_HEAT0_ADDR, temp)
self._set_regs(RES_HEAT0_ADDR + nb_profile, temp)
def set_gas_heater_duration(self, value, nb_profile=0):
"""Set gas sensor heater duration
Heating durations between 1 ms and 4032 ms can be configured.
Approximately 20–30 ms are necessary for the heater to reach the intended target temperature.
:param value: Heating duration in milliseconds.
When setting an nb_profile other than 0,
make sure to select it with select_gas_heater_profile.
"""
if nb_profile > NBCONV_MAX or value < NBCONV_MIN:
raise ValueError("Profile '{}' should be between {} and {}".format(nb_profile, NBCONV_MIN, NBCONV_MAX))
def set_gas_heater_duration(self, value):
"""Set gas sensor heater duration"""
self.gas_settings.heatr_dur = value
temp = self._calc_heater_duration(self.gas_settings.heatr_dur)
self._set_regs(GAS_WAIT0_ADDR, temp)
self._set_regs(GAS_WAIT0_ADDR + nb_profile, temp)
def set_power_mode(self, value, blocking=True):
"""Set power mode"""
@ -131,10 +210,6 @@ class BME680(BME680Data):
self.power_mode = value
self._set_bits(CONF_T_P_MODE_ADDR, MODE_MSK, MODE_POS, value)
#temp = self._get_regs(CONF_T_P_MODE_ADDR, 1)
#temp &= ~ MODE_MSK
#temp |= self.power_mode
#self._set_regs(CONF_T_P_MODE_ADDR, temp)
while blocking and self.get_power_mode() != self.power_mode:
time.sleep(POLL_PERIOD_MS / 1000.0)
@ -151,12 +226,12 @@ class BME680(BME680Data):
"""
self.set_power_mode(FORCED_MODE)
tries = 10
for x in range(10):
for attempt in range(10):
regs = self._get_regs(FIELD0_ADDR, FIELD_LENGTH)
self.data.status = regs[0] & NEW_DATA_MSK
# Contains the nb_profile used to obtain the current measurement
self.data.gas_index = regs[0] & GAS_INDEX_MSK
self.data.meas_index = regs[1]

3
bme680/constants.py
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@ -133,7 +133,7 @@ GAS_SENSOR_SEL = GAS_MEAS_SEL | RUN_GAS_SEL | NBCONV_SEL
# Number of conversion settings
NBCONV_MIN = 0
NBCONV_MAX = 10
NBCONV_MAX = 9 # Was 10, but there are only 10 settings: 0 1 2 ... 8 9
# Mask definitions
GAS_MEAS_MSK = 0x30
@ -165,6 +165,7 @@ OSP_POS = 2
OSH_POS = 0
RUN_GAS_POS = 4
MODE_POS = 0
NBCONV_POS = 0
# Array Index to Field data mapping for Calibration Data
T2_LSB_REG = 1

6
livetest.py
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@ -26,6 +26,12 @@ for name in dir(sensor.data):
sensor.set_gas_heater_temperature(320)
sensor.set_gas_heater_duration(150)
sensor.select_gas_heater_profile(0)
# Up to 10 heater profiles can be configured, each
# with their own temperature and duration.
# sensor.set_gas_heater_profile(200, 150, nb_profile=1)
# sensor.select_gas_heater_profile(1)
try:
while True: