Merge upstream

README.md

@@ -27,4 +27,5 @@ In all cases you will have to enable the i2c bus.
 
 ## Documentation & Support
 
-* Guides and tutorials - https://learn.pimoroni.com/bme680
+* Guides and tutorials - https://learn.pimoroni.com/bme680-breakout
+* Get help - http://forums.pimoroni.com/c/support

examples/compensated-temperature.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+
+import time
+import bme680
+from subprocess import PIPE, Popen
+
+
+print("""compensated-temperature.py - Use the CPU temperature to compensate temperature
+readings from the BME680 sensor. Method adapted from Initial State's Enviro pHAT
+review: https://medium.com/@InitialState/tutorial-review-enviro-phat-for-raspberry-pi-4cd6d8c63441
+
+Press Ctrl+C to exit!
+
+""")
+
+try:
+    sensor = bme680.BME680(bme680.I2C_ADDR_PRIMARY)
+except IOError:
+    sensor = bme680.BME680(bme680.I2C_ADDR_SECONDARY)
+
+# These oversampling settings can be tweaked to
+# change the balance between accuracy and noise in
+# the data.
+
+sensor.set_humidity_oversample(bme680.OS_2X)
+sensor.set_pressure_oversample(bme680.OS_4X)
+sensor.set_temperature_oversample(bme680.OS_8X)
+sensor.set_filter(bme680.FILTER_SIZE_3)
+
+
+# Gets the CPU temperature in degrees C
+def get_cpu_temperature():
+    process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE)
+    output, _error = process.communicate()
+    return float(output[output.index('=') + 1:output.rindex("'")])
+
+
+factor = 1.0  # Smaller numbers adjust temp down, vice versa
+smooth_size = 10  # Dampens jitter due to rapid CPU temp changes
+
+cpu_temps = []
+
+while True:
+    if sensor.get_sensor_data():
+        cpu_temp = get_cpu_temperature()
+        cpu_temps.append(cpu_temp)
+
+        if len(cpu_temps) > smooth_size:
+            cpu_temps = cpu_temps[1:]
+
+        smoothed_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
+        raw_temp = sensor.data.temperature
+        comp_temp = raw_temp - ((smoothed_cpu_temp - raw_temp) / factor)
+
+        print("Compensated temperature: {:05.2f} *C".format(comp_temp))
+
+        time.sleep(1.0)

examples/indoor-air-quality.py

@@ -1,14 +1,15 @@
 #!/usr/bin/env python
+
 import bme680
 import time
 
-print("""Estimate indoor air quality
+print("""indoor-air-quality.py - Estimates indoor air quality.
 
 Runs the sensor for a burn-in period, then uses a
 combination of relative humidity and gas resistance
 to estimate indoor air quality as a percentage.
 
-Press Ctrl+C to exit
+Press Ctrl+C to exit!
 
 """)
 

examples/read-all.py

@@ -1,10 +1,11 @@
 #!/usr/bin/env python
+
 import bme680
 import time
 
-print("""Display Temperature, Pressure, Humidity and Gas
+print("""read-all.py - Displays temperature, pressure, humidity, and gas.
 
-Press Ctrl+C to exit
+Press Ctrl+C to exit!
 
 """)
 

examples/temperature-offset.py

@@ -1,7 +1,11 @@
 #!/usr/bin/env python
+
 import bme680
 
-print("""Display Temperature, Pressure and Humidity with different offsets.
+print("""temperature-offset.py - Displays temperature, pressure, and humidity with different offsets.
+
+Press Ctrl+C to exit!
+
 """)
 
 try:

examples/temperature-pressure-humidity.py

@@ -1,7 +1,8 @@
 #!/usr/bin/env python
+
 import bme680
 
-print("""Display Temperature, Pressure and Humidity
+print("""temperature-pressure-humidity.py - Displays temperature, pressure, and humidity.
 
 If you don't need gas readings, then you can read temperature,
 pressure and humidity quickly.
@@ -28,12 +29,10 @@ print('Polling:')
 try:
     while True:
         if sensor.get_sensor_data():
-
             output = '{0:.2f} C,{1:.2f} hPa,{2:.3f} %RH'.format(
                 sensor.data.temperature,
                 sensor.data.pressure / 100.0,
                 sensor.data.humidity)
-
             print(output)
 
 except KeyboardInterrupt:

library/bme680/__init__.py

@@ -10,10 +10,11 @@ __version__ = '1.0.5'
 
 # Export constants to global namespace
 # so end-users can "from BME680 import NAME"
-for key in constants.__dict__:
-    value = constants.__dict__[key]
-    if key not in globals():
-        globals()[key] = value
+if hasattr(constants, '__dict__'):
+    for key in constants.__dict__:
+        value = constants.__dict__[key]
+        if key not in globals():
+            globals()[key] = value
 
 
 class BME680(BME680Data):

library/setup.cfg

@@ -12,3 +12,4 @@ ignore =
 	E501
 	F403
 	F405
+	W504

library/tests/conftest.py

@@ -0,0 +1,101 @@
+import sys
+import mock
+import pytest
+import bme680
+from bme680.constants import CalibrationData
+
+
+class MockSMBus:
+    """Mock a basic non-presence SMBus device to cause BME680 to fail.
+
+    Returns 0 in all cases, so that CHIP_ID will never match.
+
+    """
+
+    def __init__(self, bus):  # noqa D107
+        pass
+
+    def read_byte_data(self, addr, register):
+        """Return 0 for all read attempts."""
+        return 0
+
+
+class MockSMBusPresent:
+    """Mock enough of the BME680 for the library to initialise and test."""
+
+    def __init__(self, bus):
+        """Initialise with test data."""
+        self.regs = [0 for _ in range(256)]
+        self.regs[bme680.CHIP_ID_ADDR] = bme680.CHIP_ID
+
+    def read_byte_data(self, addr, register):
+        """Read a single byte from fake registers."""
+        return self.regs[register]
+
+    def write_byte_data(self, addr, register, value):
+        """Write a single byte to fake registers."""
+        self.regs[register] = value
+
+    def read_i2c_block_data(self, addr, register, length):
+        """Read up to length bytes from register."""
+        return self.regs[register:register + length]
+
+
+@pytest.fixture(scope='function', autouse=False)
+def smbus_notpresent():
+    """Mock smbus module."""
+    smbus = mock.MagicMock()
+    smbus.SMBus = MockSMBus
+    sys.modules['smbus'] = smbus
+    yield smbus
+    del sys.modules['smbus']
+
+
+@pytest.fixture(scope='function', autouse=False)
+def smbus():
+    """Mock smbus module."""
+    smbus = mock.MagicMock()
+    smbus.SMBus = MockSMBusPresent
+    sys.modules['smbus'] = smbus
+    yield smbus
+    del sys.modules['smbus']
+
+
+@pytest.fixture(scope='function', autouse=False)
+def calibration():
+    """Mock bme680 calibration."""
+    calibration = CalibrationData()
+    # Dump of calibration data borrowed from:
+    # https://github.com/pimoroni/bme680-python/issues/11
+    data = {
+        'par_gh1': -30,
+        'par_gh2': -24754,
+        'par_gh3': 18,
+        'par_h1': 676,
+        'par_h2': 1029,
+        'par_h3': 0,
+        'par_h4': 45,
+        'par_h5': 20,
+        'par_h6': 120,
+        'par_h7': -100,
+        'par_p1': 36673,
+        'par_p10': 30,
+        'par_p2': -10515,
+        'par_p3': 88,
+        'par_p4': 7310,
+        'par_p5': -129,
+        'par_p6': 30,
+        'par_p7': 46,
+        'par_p8': -3177,
+        'par_p9': -2379,
+        'par_t1': 26041,
+        'par_t2': 26469,
+        'par_t3': 3,
+        'range_sw_err': 0,
+        'res_heat_range': 1,
+        'res_heat_val': 48,
+        't_fine': 136667
+    }
+    for k, v in data.items():
+        setattr(calibration, k, v)
+    return calibration

library/tests/test_compensation.py

@@ -0,0 +1,41 @@
+import bme680
+
+
+def test_calc_temperature(smbus, calibration):
+    """Validate temperature calculation against mock calibration data."""
+    sensor = bme680.BME680()
+    sensor.calibration_data = calibration
+    assert sensor._calc_temperature(501240) == 2669
+    assert sensor.calibration_data.t_fine == 136667
+
+
+def test_calc_pressure(smbus, calibration):
+    """Validate pressure calculation against mock calibration data."""
+    sensor = bme680.BME680()
+    sensor.calibration_data = calibration
+    sensor._calc_temperature(501240)
+    assert sensor._calc_pressure(353485) == 98712
+
+
+def test_calc_humidity(smbus, calibration):
+    """Validate humidity calculation against mock calibration data."""
+    sensor = bme680.BME680()
+    sensor.calibration_data = calibration
+    sensor._calc_temperature(501240)
+    assert sensor._calc_humidity(19019) == 42402
+
+
+def test_calc_gas_resistance(smbus, calibration):
+    """Validate gas calculation against mock calibration data."""
+    sensor = bme680.BME680()
+    sensor.calibration_data = calibration
+    assert int(sensor._calc_gas_resistance(0, 0)) == 12946860
+
+
+def test_temp_offset(smbus, calibration):
+    """Validate temperature calculation with offset against mock calibration data."""
+    sensor = bme680.BME680()
+    sensor.calibration_data = calibration
+    sensor.set_temp_offset(1.99)
+    assert sensor._calc_temperature(501240) == 2669 + 199
+    assert sensor.calibration_data.t_fine == 146830

library/tests/test_setup.py

@@ -1,57 +1,13 @@
-import sys
-import mock
 import pytest
 import bme680
 
 
-class MockSMBus:
-    """Mock a basic non-presence SMBus device to cause BME680 to fail.
-
-    Returns 0 in all cases, so that CHIP_ID will never match.
-
-    """
-
-    def __init__(self, bus):  # noqa D107
-        pass
-
-    def read_byte_data(self, addr, register):
-        """Return 0 for all read attempts."""
-        return 0
-
-
-class MockSMBusPresent:
-    """Mock enough of the BME680 for the library to initialise and test."""
-
-    def __init__(self, bus):
-        """Initialise with test data."""
-        self.regs = [0 for _ in range(256)]
-        self.regs[bme680.CHIP_ID_ADDR] = bme680.CHIP_ID
-
-    def read_byte_data(self, addr, register):
-        """Read a single byte from fake registers."""
-        return self.regs[register]
-
-    def write_byte_data(self, addr, register, value):
-        """Write a single byte to fake registers."""
-        self.regs[register] = value
-
-    def read_i2c_block_data(self, addr, register, length):
-        """Read up to length bytes from register."""
-        return self.regs[register:register + length]
-
-
-def test_setup_not_present():
+def test_setup_not_present(smbus_notpresent):
     """Mock the adbsence of a BME680 and test initialisation."""
-    sys.modules['smbus'] = mock.MagicMock()
-    sys.modules['smbus'].SMBus = MockSMBus
-
     with pytest.raises(RuntimeError):
         sensor = bme680.BME680()  # noqa F841
 
 
-def test_setup_mock_present():
+def test_setup_mock_present(smbus):
     """Mock the presence of a BME680 and test initialisation."""
-    sys.modules['smbus'] = mock.MagicMock()
-    sys.modules['smbus'].SMBus = MockSMBusPresent
-
     sensor = bme680.BME680()  # noqa F841