Provide proxies for I2C and SPI

adafruit_bme280/advanced.py

@@ -31,6 +31,7 @@
 """
 from micropython import const
 from adafruit_bme280.basic import Adafruit_BME280
+from adafruit_bme280.protocol import I2C_Impl, SPI_Impl
 
 try:
     import typing  # pylint: disable=unused-import
@@ -141,14 +142,14 @@ class Adafruit_BME280_Advanced(Adafruit_BME280):
     """
 
     # pylint: disable=too-many-instance-attributes
-    def __init__(self) -> None:
+    def __init__(self, proxy: typing.Union[I2C_Impl, SPI_Impl]) -> None:
         """Check the BME280 was found, read the coefficients and enable the sensor"""
         self._overscan_humidity = OVERSCAN_X1
         self._overscan_temperature = OVERSCAN_X1
         self._overscan_pressure = OVERSCAN_X16
         self._mode = MODE_SLEEP
         self._t_standby = STANDBY_TC_125
-        super().__init__()
+        super().__init__(proxy)
 
     @property
     def standby_period(self) -> int:
@@ -317,25 +318,7 @@ class Adafruit_BME280_I2C(Adafruit_BME280_Advanced):
     """
 
     def __init__(self, i2c: I2C, address: int = _BME280_ADDRESS) -> None:
-        from adafruit_bus_device import (  # pylint: disable=import-outside-toplevel
-            i2c_device,
-        )
-
-        self._i2c = i2c_device.I2CDevice(i2c, address)
-        super().__init__()
-
-    def _read_register(self, register: int, length: int) -> bytearray:
-        with self._i2c as i2c:
-            i2c.write(bytes([register & 0xFF]))
-            result = bytearray(length)
-            i2c.readinto(result)
-            # print("$%02X => %s" % (register, [hex(i) for i in result]))
-            return result
-
-    def _write_register_byte(self, register: int, value: int) -> None:
-        with self._i2c as i2c:
-            i2c.write(bytes([register & 0xFF, value & 0xFF]))
-            # print("$%02X <= 0x%02X" % (register, value))
+        super().__init__(I2C_Impl(i2c, address))
 
 
 class Adafruit_BME280_SPI(Adafruit_BME280_Advanced):
@@ -387,23 +370,4 @@ class Adafruit_BME280_SPI(Adafruit_BME280_Advanced):
     """
 
     def __init__(self, spi: SPI, cs: DigitalInOut, baudrate: int = 100000) -> None:
-        from adafruit_bus_device import (  # pylint: disable=import-outside-toplevel
-            spi_device,
-        )
-
-        self._spi = spi_device.SPIDevice(spi, cs, baudrate=baudrate)
-        super().__init__()
-
-    def _read_register(self, register: int, length: int) -> bytearray:
-        register = (register | 0x80) & 0xFF  # Read single, bit 7 high.
-        with self._spi as spi:
-            spi.write(bytearray([register]))  # pylint: disable=no-member
-            result = bytearray(length)
-            spi.readinto(result)  # pylint: disable=no-member
-            # print("$%02X => %s" % (register, [hex(i) for i in result]))
-            return result
-
-    def _write_register_byte(self, register: int, value: int) -> None:
-        register &= 0x7F  # Write, bit 7 low.
-        with self._spi as spi:
-            spi.write(bytes([register, value & 0xFF]))  # pylint: disable=no-member
+        super().__init__(SPI_Impl(spi, cs, baudrate))

adafruit_bme280/basic.py

@@ -34,6 +34,7 @@
 from time import sleep
 
 from micropython import const
+from adafruit_bme280.protocol import I2C_Impl, SPI_Impl
 
 try:
     import typing  # pylint: disable=unused-import
@@ -88,9 +89,10 @@ class Adafruit_BME280:
     """
 
     # pylint: disable=too-many-instance-attributes
-    def __init__(self) -> None:
+    def __init__(self, bus_implementation: typing.Union[I2C_Impl, SPI_Impl]) -> None:
         """Check the BME280 was found, read the coefficients and enable the sensor"""
         # Check device ID.
+        self._bus_implementation = bus_implementation
         chip_id = self._read_byte(_BME280_REGISTER_CHIPID)
         if _BME280_CHIPID != chip_id:
             raise RuntimeError("Failed to find BME280! Chip ID 0x%x" % chip_id)
@@ -309,10 +311,10 @@ def _read24(self, register: int) -> float:
         return ret
 
     def _read_register(self, register: int, length: int) -> bytearray:
-        raise NotImplementedError()
+        return self._bus_implementation.read_register(register, length)
 
     def _write_register_byte(self, register: int, value: int) -> None:
-        raise NotImplementedError()
+        self._bus_implementation.write_register_byte(register, value)
 
 
 class Adafruit_BME280_I2C(Adafruit_BME280):
@@ -363,24 +365,7 @@ class Adafruit_BME280_I2C(Adafruit_BME280):
     """
 
     def __init__(self, i2c: I2C, address: int = 0x77) -> None:  # BME280_ADDRESS
-        from adafruit_bus_device import (  # pylint: disable=import-outside-toplevel
-            i2c_device,
-        )
-
-        self._i2c = i2c_device.I2CDevice(i2c, address)
-        super().__init__()
-
-    def _read_register(self, register: int, length: int) -> bytearray:
-        with self._i2c as i2c:
-            i2c.write(bytes([register & 0xFF]))
-            result = bytearray(length)
-            i2c.readinto(result)
-            return result
-
-    def _write_register_byte(self, register: int, value: int) -> None:
-        with self._i2c as i2c:
-            i2c.write(bytes([register & 0xFF, value & 0xFF]))
-            # print("$%02X <= 0x%02X" % (register, value))
+        super().__init__(I2C_Impl(i2c, address))
 
 
 class Adafruit_BME280_SPI(Adafruit_BME280):
@@ -433,22 +418,4 @@ class Adafruit_BME280_SPI(Adafruit_BME280):
     """
 
     def __init__(self, spi: SPI, cs: DigitalInOut, baudrate: int = 100000) -> None:
-        from adafruit_bus_device import (  # pylint: disable=import-outside-toplevel
-            spi_device,
-        )
-
-        self._spi = spi_device.SPIDevice(spi, cs, baudrate=baudrate)
-        super().__init__()
-
-    def _read_register(self, register: int, length: int) -> bytearray:
-        register = (register | 0x80) & 0xFF  # Read single, bit 7 high.
-        with self._spi as spi:
-            spi.write(bytearray([register]))  # pylint: disable=no-member
-            result = bytearray(length)
-            spi.readinto(result)  # pylint: disable=no-member
-            return result
-
-    def _write_register_byte(self, register: int, value: int) -> None:
-        register &= 0x7F  # Write, bit 7 low.
-        with self._spi as spi:
-            spi.write(bytes([register, value & 0xFF]))  # pylint: disable=no-member
+        super().__init__(SPI_Impl(spi, cs, baudrate))

adafruit_bme280/protocol.py

@@ -0,0 +1,58 @@
+# SPDX-FileCopyrightText: 2022 Randall Bohn (dexter)
+#
+# SPDX-License-Identifier: MIT
+"Provides the protocol objects for I2C and SPI"
+
+from busio import I2C, SPI
+from digitalio import DigitalInOut
+
+
+class I2C_Impl:
+    "Protocol implementation for the I2C bus."
+
+    def __init__(self, i2c: I2C, address: int) -> None:
+        from adafruit_bus_device import (  # pylint: disable=import-outside-toplevel
+            i2c_device,
+        )
+
+        self._i2c = i2c_device.I2CDevice(i2c, address)
+
+    def read_register(self, register: int, length: int) -> bytearray:
+        "Read from the device register."
+        with self._i2c as i2c:
+            i2c.write(bytes([register & 0xFF]))
+            result = bytearray(length)
+            i2c.readinto(result)
+            return result
+
+    def write_register_byte(self, register: int, value: int) -> None:
+        "Write to the device register."
+        with self._i2c as i2c:
+            i2c.write(bytes([register & 0xFF, value & 0xFF]))
+
+
+class SPI_Impl:
+    "Protocol implemenation for the SPI bus."
+
+    def __init__(self, spi: SPI, cs: DigitalInOut, baudrate: int = 100000) -> None:
+        from adafruit_bus_device import (  # pylint: disable=import-outside-toplevel
+            spi_device,
+        )
+
+        self._spi = spi_device.SPIDevice(spi, cs, baudrate=baudrate)
+
+    def read_register(self, register: int, length: int) -> bytearray:
+        "Read from the device register."
+        register = (register | 0x80) & 0xFF  # Read single, bit 7 high.
+        with self._spi as spi:
+            spi.write(bytearray([register]))  # pylint: disable=no-member
+            result = bytearray(length)
+            spi.readinto(result)  # pylint: disable=no-member
+            # print("$%02X => %s" % (register, [hex(i) for i in result]))
+            return result
+
+    def write_register_byte(self, register: int, value: int) -> None:
+        "Write value to the device register."
+        register &= 0x7F  # Write, bit 7 low.
+        with self._spi as spi:
+            spi.write(bytes([register, value & 0xFF]))  # pylint: disable=no-member