fix: fixed BMP180

Author: AsCress

pslab/external/BMP180.py

@@ -0,0 +1,186 @@
+"""BMP180 Altimeter."""
+
+import time
+import logging
+import struct
+from pslab.bus import I2CSlave
+
+# BMP180 default address
+_ADDRESS = 0x77
+
+# Operating Modes
+_ULTRALOWPOWER = 0
+_STANDARD = 1
+_HIGHRES = 2
+_ULTRAHIGHRES = 3
+
+# BMP180 Registers
+_CAL_AC1 = 0xAA  # R   Calibration data (16 bits)
+_CAL_AC2 = 0xAC  # R   Calibration data (16 bits)
+_CAL_AC3 = 0xAE  # R   Calibration data (16 bits)
+_CAL_AC4 = 0xB0  # R   Calibration data (16 bits)
+_CAL_AC5 = 0xB2  # R   Calibration data (16 bits)
+_CAL_AC6 = 0xB4  # R   Calibration data (16 bits)
+_CAL_B1 = 0xB6  # R   Calibration data (16 bits)
+_CAL_B2 = 0xB8  # R   Calibration data (16 bits)
+_CAL_MB = 0xBA  # R   Calibration data (16 bits)
+_CAL_MC = 0xBC  # R   Calibration data (16 bits)
+_CAL_MD = 0xBE  # R   Calibration data (16 bits)
+_CONTROL = 0xF4
+_TEMPDATA = 0xF6
+_PRESSUREDATA = 0xF6
+
+# Commands
+_READTEMPCMD = 0x2E
+_READPRESSURECMD = 0x34
+
+_logger = logging.getLogger(__name__)
+
+
+class BMP180(I2CSlave):
+    """Class to interface with the BMP180 Altimeter.
+
+    Parameters
+    ----------
+    mode : int, optional
+        The mode of operation for the sensor, determining the oversampling setting.
+        The default mode is `_HIGHRES`. This parameter affects the precision and speed
+        of the temperature and pressure measurements.
+
+    **kwargs : dict, optional
+        Additional keyword arguments, such as:
+        - address (int): The I2C address of the BMP180 sensor. Default is `_ADDRESS`.
+
+    Attributes
+    ----------
+    temperature : float
+        The measured temperature in degrees Celsius.
+
+    pressure : float
+        The measured pressure in Pa (Pascals).
+
+    altitude : float
+        The calculated altitude in meters based on the current pressure reading
+        and a reference sea level pressure.
+    """
+
+    NUMPLOTS = 3
+    PLOTNAMES = ["Temperature", "Pressure", "Altitude"]
+    name = "BMP180 Altimeter"
+
+    def __init__(self, mode=_HIGHRES, **kwargs):
+        self._ADDRESS = kwargs.get("address", _ADDRESS)
+        super().__init__(self._ADDRESS)
+        self._mode = mode
+
+        # Load calibration values
+        self._ac1 = self._read_int16(_CAL_AC1)
+        self._ac2 = self._read_int16(_CAL_AC2)
+        self._ac3 = self._read_int16(_CAL_AC3)
+        self._ac4 = self._read_uint16(_CAL_AC4)
+        self._ac5 = self._read_uint16(_CAL_AC5)
+        self._ac6 = self._read_uint16(_CAL_AC6)
+        self._b1 = self._read_int16(_CAL_B1)
+        self._b2 = self._read_int16(_CAL_B2)
+        self._mb = self._read_int16(_CAL_MB)
+        self._mc = self._read_int16(_CAL_MC)
+        self._md = self._read_int16(_CAL_MD)
+
+        _logger.debug(f"ac1: {self._ac1}")
+        _logger.debug(f"ac2: {self._ac2}")
+        _logger.debug(f"ac3: {self._ac3}")
+        _logger.debug(f"ac4: {self._ac4}")
+        _logger.debug(f"ac5: {self._ac5}")
+        _logger.debug(f"ac6: {self._ac6}")
+        _logger.debug(f"b1: {self._b1}")
+        _logger.debug(f"b2: {self._b2}")
+        _logger.debug(f"mb: {self._mb}")
+        _logger.debug(f"mc: {self._mc}")
+        _logger.debug(f"md: {self._md}")
+
+    def _read_int16(self, addr):
+        BE_INT16 = struct.Struct(">h")  # signed short, big endian
+        return BE_INT16.unpack(self.read(2, addr))[0]
+
+    def _read_uint16(self, addr):
+        BE_UINT16 = struct.Struct(">H")  # unsigned short, big endian
+        return BE_UINT16.unpack(self.read(2, addr))[0]
+
+    def _read_raw_temperature(self):
+        """Read the raw temperature from the sensor."""
+        self.write([_READTEMPCMD], _CONTROL)
+        time.sleep(0.005)
+        raw = self._read_uint16(_TEMPDATA)
+        return raw
+
+    @property
+    def temperature(self):
+        """Get the actual temperature in degrees celsius."""
+        ut = self._read_raw_temperature()
+        # Calculations from section 3.5 of the datasheet
+        x1 = ((ut - self._ac6) * self._ac5) >> 15
+        x2 = (self._mc << 11) // (x1 + self._md)
+        b5 = x1 + x2
+        temp = ((b5 + 8) >> 4) / 10.0
+        return temp
+
+    @property
+    def oversampling(self):
+        """oversampling : int
+        The oversampling setting used by the sensor. This attribute is settable and
+        determines the trade-off between measurement accuracy and speed. Possible values
+        include `_ULTRALOWPOWER`, `_STANDARD`, `_HIGHRES`, and `_ULTRAHIGHRES`.
+        """
+        return self._mode
+
+    @oversampling.setter
+    def oversampling(self, value):
+        self._mode = value
+
+    def _read_raw_pressure(self):
+        """Read the raw pressure level from the sensor."""
+        delays = [0.005, 0.008, 0.014, 0.026]
+        self.write([_READPRESSURECMD + (self._mode << 6)], _CONTROL)
+        time.sleep(delays[self._mode])
+        msb = self.read_byte(_PRESSUREDATA) & 0xFF
+        lsb = self.read_byte(_PRESSUREDATA + 1) & 0xFF
+        xlsb = self.read_byte(_PRESSUREDATA + 2) & 0xFF
+        raw = ((msb << 16) + (lsb << 8) + xlsb) >> (8 - self._mode)
+        return raw
+
+    @property
+    def pressure(self):
+        """Get the actual pressure in Pascals."""
+        ut = self._read_raw_temperature()
+        up = self._read_raw_pressure()
+        # Calculations from section 3.5 of the datasheet
+        x1 = ((ut - self._ac6) * self._ac5) >> 15
+        x2 = (self._mc << 11) // (x1 + self._md)
+        b5 = x1 + x2
+        # Pressure Calculations
+        b6 = b5 - 4000
+        x1 = (self._b2 * (b6 * b6) >> 12) >> 11
+        x2 = (self._ac2 * b6) >> 11
+        x3 = x1 + x2
+        b3 = (((self._ac1 * 4 + x3) << self._mode) + 2) // 4
+        x1 = (self._ac3 * b6) >> 13
+        x2 = (self._b1 * ((b6 * b6) >> 12)) >> 16
+        x3 = ((x1 + x2) + 2) >> 2
+        b4 = (self._ac4 * (x3 + 32768)) >> 15
+        b7 = (up - b3) * (50000 >> self._mode)
+        if b7 < 0x80000000:
+            p = (b7 * 2) // b4
+        else:
+            p = (b7 // b4) * 2
+        x1 = (p >> 8) * (p >> 8)
+        x1 = (x1 * 3038) >> 16
+        x2 = (-7357 * p) >> 16
+        pres = p + ((x1 + x2 + 3791) >> 4)
+        return pres
+
+    @property
+    def altitude(self):
+        # Calculation from section 3.6 of datasheet
+        pressure = float(self.pressure)
+        alt = 44330.0 * (1.0 - pow(pressure / 101325.0, (1.0 / 5.255)))
+        return alt