5050import time
5151import math
5252from micropython import const
53+
5354try :
5455 import struct
5556except ImportError :
8687
8788_BME680_RUNGAS = const (0x10 )
8889
89- _LOOKUP_TABLE_1 = (2147483647.0 , 2147483647.0 , 2147483647.0 , 2147483647.0 , 2147483647.0 ,
90- 2126008810.0 , 2147483647.0 , 2130303777.0 , 2147483647.0 , 2147483647.0 ,
91- 2143188679.0 , 2136746228.0 , 2147483647.0 , 2126008810.0 , 2147483647.0 ,
92- 2147483647.0 )
93-
94- _LOOKUP_TABLE_2 = (4096000000.0 , 2048000000.0 , 1024000000.0 , 512000000.0 , 255744255.0 , 127110228.0 ,
95- 64000000.0 , 32258064.0 , 16016016.0 , 8000000.0 , 4000000.0 , 2000000.0 , 1000000.0 ,
96- 500000.0 , 250000.0 , 125000.0 )
90+ _LOOKUP_TABLE_1 = (
91+ 2147483647.0 ,
92+ 2147483647.0 ,
93+ 2147483647.0 ,
94+ 2147483647.0 ,
95+ 2147483647.0 ,
96+ 2126008810.0 ,
97+ 2147483647.0 ,
98+ 2130303777.0 ,
99+ 2147483647.0 ,
100+ 2147483647.0 ,
101+ 2143188679.0 ,
102+ 2136746228.0 ,
103+ 2147483647.0 ,
104+ 2126008810.0 ,
105+ 2147483647.0 ,
106+ 2147483647.0 ,
107+ )
108+
109+ _LOOKUP_TABLE_2 = (
110+ 4096000000.0 ,
111+ 2048000000.0 ,
112+ 1024000000.0 ,
113+ 512000000.0 ,
114+ 255744255.0 ,
115+ 127110228.0 ,
116+ 64000000.0 ,
117+ 32258064.0 ,
118+ 16016016.0 ,
119+ 8000000.0 ,
120+ 4000000.0 ,
121+ 2000000.0 ,
122+ 1000000.0 ,
123+ 500000.0 ,
124+ 250000.0 ,
125+ 125000.0 ,
126+ )
97127
98128
99129def _read24 (arr ):
100130 """Parse an unsigned 24-bit value as a floating point and return it."""
101131 ret = 0.0
102- #print([hex(i) for i in arr])
132+ # print([hex(i) for i in arr])
103133 for b in arr :
104134 ret *= 256.0
105135 ret += float (b & 0xFF )
@@ -111,6 +141,7 @@ class Adafruit_BME680:
111141
112142 :param int refresh_rate: Maximum number of readings per second. Faster property reads
113143 will be from the previous reading."""
144+
114145 def __init__ (self , * , refresh_rate = 10 ):
115146 """Check the BME680 was found, read the coefficients and enable the sensor for continuous
116147 reads."""
@@ -120,7 +151,7 @@ def __init__(self, *, refresh_rate=10):
120151 # Check device ID.
121152 chip_id = self ._read_byte (_BME680_REG_CHIPID )
122153 if chip_id != _BME680_CHIPID :
123- raise RuntimeError (' Failed to find BME680! Chip ID 0x%x' % chip_id )
154+ raise RuntimeError (" Failed to find BME680! Chip ID 0x%x" % chip_id )
124155
125156 self ._read_calibration ()
126157
@@ -199,7 +230,7 @@ def filter_size(self, size):
199230 def temperature (self ):
200231 """The compensated temperature in degrees celsius."""
201232 self ._perform_reading ()
202- calc_temp = ((( self ._t_fine * 5 ) + 128 ) / 256 )
233+ calc_temp = ((self ._t_fine * 5 ) + 128 ) / 256
203234 return calc_temp / 100
204235
205236 @property
@@ -211,31 +242,49 @@ def pressure(self):
211242 var2 = (var2 * self ._pressure_calibration [5 ]) / 4
212243 var2 = var2 + (var1 * self ._pressure_calibration [4 ] * 2 )
213244 var2 = (var2 / 4 ) + (self ._pressure_calibration [3 ] * 65536 )
214- var1 = (((((var1 / 4 ) * (var1 / 4 )) / 8192 ) *
215- (self ._pressure_calibration [2 ] * 32 ) / 8 ) +
216- ((self ._pressure_calibration [1 ] * var1 ) / 2 ))
245+ var1 = (
246+ (((var1 / 4 ) * (var1 / 4 )) / 8192 )
247+ * (self ._pressure_calibration [2 ] * 32 )
248+ / 8
249+ ) + ((self ._pressure_calibration [1 ] * var1 ) / 2 )
217250 var1 = var1 / 262144
218251 var1 = ((32768 + var1 ) * self ._pressure_calibration [0 ]) / 32768
219252 calc_pres = 1048576 - self ._adc_pres
220253 calc_pres = (calc_pres - (var2 / 4096 )) * 3125
221254 calc_pres = (calc_pres / var1 ) * 2
222- var1 = (self ._pressure_calibration [8 ] * (((calc_pres / 8 ) * (calc_pres / 8 )) / 8192 )) / 4096
255+ var1 = (
256+ self ._pressure_calibration [8 ] * (((calc_pres / 8 ) * (calc_pres / 8 )) / 8192 )
257+ ) / 4096
223258 var2 = ((calc_pres / 4 ) * self ._pressure_calibration [7 ]) / 8192
224259 var3 = (((calc_pres / 256 ) ** 3 ) * self ._pressure_calibration [9 ]) / 131072
225- calc_pres += (( var1 + var2 + var3 + (self ._pressure_calibration [6 ] * 128 )) / 16 )
226- return calc_pres / 100
260+ calc_pres += (var1 + var2 + var3 + (self ._pressure_calibration [6 ] * 128 )) / 16
261+ return calc_pres / 100
227262
228263 @property
229264 def humidity (self ):
230265 """The relative humidity in RH %"""
231266 self ._perform_reading ()
232267 temp_scaled = ((self ._t_fine * 5 ) + 128 ) / 256
233- var1 = ((self ._adc_hum - (self ._humidity_calibration [0 ] * 16 )) -
234- ((temp_scaled * self ._humidity_calibration [2 ]) / 200 ))
235- var2 = (self ._humidity_calibration [1 ] *
236- (((temp_scaled * self ._humidity_calibration [3 ]) / 100 ) +
237- (((temp_scaled * ((temp_scaled * self ._humidity_calibration [4 ]) / 100 )) /
238- 64 ) / 100 ) + 16384 )) / 1024
268+ var1 = (self ._adc_hum - (self ._humidity_calibration [0 ] * 16 )) - (
269+ (temp_scaled * self ._humidity_calibration [2 ]) / 200
270+ )
271+ var2 = (
272+ self ._humidity_calibration [1 ]
273+ * (
274+ ((temp_scaled * self ._humidity_calibration [3 ]) / 100 )
275+ + (
276+ (
277+ (
278+ temp_scaled
279+ * ((temp_scaled * self ._humidity_calibration [4 ]) / 100 )
280+ )
281+ / 64
282+ )
283+ / 100
284+ )
285+ + 16384
286+ )
287+ ) / 1024
239288 var3 = var1 * var2
240289 var4 = self ._humidity_calibration [5 ] * 128
241290 var4 = (var4 + ((temp_scaled * self ._humidity_calibration [6 ]) / 100 )) / 16
@@ -254,14 +303,16 @@ def humidity(self):
254303 def altitude (self ):
255304 """The altitude based on current ``pressure`` vs the sea level pressure
256305 (``sea_level_pressure``) - which you must enter ahead of time)"""
257- pressure = self .pressure # in Si units for hPascal
306+ pressure = self .pressure # in Si units for hPascal
258307 return 44330 * (1.0 - math .pow (pressure / self .sea_level_pressure , 0.1903 ))
259308
260309 @property
261310 def gas (self ):
262311 """The gas resistance in ohms"""
263312 self ._perform_reading ()
264- var1 = ((1340 + (5 * self ._sw_err )) * (_LOOKUP_TABLE_1 [self ._gas_range ])) / 65536
313+ var1 = (
314+ (1340 + (5 * self ._sw_err )) * (_LOOKUP_TABLE_1 [self ._gas_range ])
315+ ) / 65536
265316 var2 = ((self ._adc_gas * 32768 ) - 16777216 ) + var1
266317 var3 = (_LOOKUP_TABLE_2 [self ._gas_range ] * var1 ) / 512
267318 calc_gas_res = (var3 + (var2 / 2 )) / var2
@@ -276,8 +327,10 @@ def _perform_reading(self):
276327 # set filter
277328 self ._write (_BME680_REG_CONFIG , [self ._filter << 2 ])
278329 # turn on temp oversample & pressure oversample
279- self ._write (_BME680_REG_CTRL_MEAS ,
280- [(self ._temp_oversample << 5 )| (self ._pressure_oversample << 2 )])
330+ self ._write (
331+ _BME680_REG_CTRL_MEAS ,
332+ [(self ._temp_oversample << 5 ) | (self ._pressure_oversample << 2 )],
333+ )
281334 # turn on humidity oversample
282335 self ._write (_BME680_REG_CTRL_HUM , [self ._humidity_oversample ])
283336 # gas measurements enabled
@@ -295,8 +348,8 @@ def _perform_reading(self):
295348
296349 self ._adc_pres = _read24 (data [2 :5 ]) / 16
297350 self ._adc_temp = _read24 (data [5 :8 ]) / 16
298- self ._adc_hum = struct .unpack ('>H' , bytes (data [8 :10 ]))[0 ]
299- self ._adc_gas = int (struct .unpack ('>H' , bytes (data [13 :15 ]))[0 ] / 64 )
351+ self ._adc_hum = struct .unpack (">H" , bytes (data [8 :10 ]))[0 ]
352+ self ._adc_gas = int (struct .unpack (">H" , bytes (data [13 :15 ]))[0 ] / 64 )
300353 self ._gas_range = data [14 ] & 0x0F
301354
302355 var1 = (self ._adc_temp / 8 ) - (self ._temp_calibration [0 ] * 2 )
@@ -310,11 +363,13 @@ def _read_calibration(self):
310363 coeff = self ._read (_BME680_BME680_COEFF_ADDR1 , 25 )
311364 coeff += self ._read (_BME680_BME680_COEFF_ADDR2 , 16 )
312365
313- coeff = list (struct .unpack (' <hbBHhbBhhbbHhhBBBHbbbBbHhbb' bytes (coeff [1 :39 ])))
314- #print("\n\n",coeff)
366+ coeff = list (struct .unpack (" <hbBHhbBhhbbHhhBBBHbbbBbHhbb" bytes (coeff [1 :39 ])))
367+ # print("\n\n",coeff)
315368 coeff = [float (i ) for i in coeff ]
316369 self ._temp_calibration = [coeff [x ] for x in [23 , 0 , 1 ]]
317- self ._pressure_calibration = [coeff [x ] for x in [3 , 4 , 5 , 7 , 8 , 10 , 9 , 12 , 13 , 14 ]]
370+ self ._pressure_calibration = [
371+ coeff [x ] for x in [3 , 4 , 5 , 7 , 8 , 10 , 9 , 12 , 13 , 14 ]
372+ ]
318373 self ._humidity_calibration = [coeff [x ] for x in [17 , 16 , 18 , 19 , 20 , 21 , 22 ]]
319374 self ._gas_calibration = [coeff [x ] for x in [25 , 24 , 26 ]]
320375
@@ -345,9 +400,13 @@ class Adafruit_BME680_I2C(Adafruit_BME680):
345400 :param bool debug: Print debug statements when True.
346401 :param int refresh_rate: Maximum number of readings per second. Faster property reads
347402 will be from the previous reading."""
403+
348404 def __init__ (self , i2c , address = 0x77 , debug = False , * , refresh_rate = 10 ):
349405 """Initialize the I2C device at the 'address' given"""
350- from adafruit_bus_device import i2c_device
406+ from adafruit_bus_device import ( # pylint: disable=import-outside-toplevel
407+ i2c_device ,
408+ )
409+
351410 self ._i2c = i2c_device .I2CDevice (i2c , address )
352411 self ._debug = debug
353412 super ().__init__ (refresh_rate = refresh_rate )
@@ -386,38 +445,41 @@ class Adafruit_BME680_SPI(Adafruit_BME680):
386445 """
387446
388447 def __init__ (self , spi , cs , baudrate = 100000 , debug = False , * , refresh_rate = 10 ):
389- from adafruit_bus_device import spi_device
448+ from adafruit_bus_device import ( # pylint: disable=import-outside-toplevel
449+ spi_device ,
450+ )
451+
390452 self ._spi = spi_device .SPIDevice (spi , cs , baudrate = baudrate )
391453 self ._debug = debug
392454 super ().__init__ (refresh_rate = refresh_rate )
393455
394456 def _read (self , register , length ):
395457 if register != _BME680_REG_STATUS :
396- #_BME680_REG_STATUS exists in both SPI memory pages
397- #For all other registers, we must set the correct memory page
458+ # _BME680_REG_STATUS exists in both SPI memory pages
459+ # For all other registers, we must set the correct memory page
398460 self ._set_spi_mem_page (register )
399461
400462 register = (register | 0x80 ) & 0xFF # Read single, bit 7 high.
401463 with self ._spi as spi :
402- spi .write (bytearray ([register ])) #pylint: disable=no-member
464+ spi .write (bytearray ([register ])) # pylint: disable=no-member
403465 result = bytearray (length )
404- spi .readinto (result ) # pylint: disable=no-member
466+ spi .readinto (result ) # pylint: disable=no-member
405467 if self ._debug :
406468 print ("\t $%02X => %s" % (register , [hex (i ) for i in result ]))
407469 return result
408470
409471 def _write (self , register , values ):
410472 if register != _BME680_REG_STATUS :
411- #_BME680_REG_STATUS exists in both SPI memory pages
412- #For all other registers, we must set the correct memory page
473+ # _BME680_REG_STATUS exists in both SPI memory pages
474+ # For all other registers, we must set the correct memory page
413475 self ._set_spi_mem_page (register )
414476 register &= 0x7F # Write, bit 7 low.
415477 with self ._spi as spi :
416478 buffer = bytearray (2 * len (values ))
417479 for i , value in enumerate (values ):
418480 buffer [2 * i ] = register + i
419481 buffer [2 * i + 1 ] = value & 0xFF
420- spi .write (buffer ) # pylint: disable=no-member
482+ spi .write (buffer ) # pylint: disable=no-member
421483 if self ._debug :
422484 print ("\t $%02X <= %s" % (values [0 ], [hex (i ) for i in values [1 :]]))
423485
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