add Circuitpython/Linux(auto) as I2cTransceiver

Author: tyeth

sensirion_i2c_driver/__init__.py

@@ -5,7 +5,13 @@
 from .version import version as __version__  # noqa: F401
 from .device import I2cDevice  # noqa: F401
 from .connection import I2cConnection  # noqa: F401
-from .linux_i2c_transceiver import LinuxI2cTransceiver  # noqa: F401
+
+import sys
+if sys.implementation.name.lower() == "circuitpython":
+    from .circuitpython_i2c_transceiver import CircuitPythonI2cTransceiver as I2cTransceiver
+else:
+    from .linux_i2c_transceiver import LinuxI2cTransceiver as I2cTransceiver
+
 from .command import I2cCommand  # noqa: F401
 from .sensirion_command import SensirionI2cCommand  # noqa: F401
 from .crc_calculator import CrcCalculator  # noqa: F401

sensirion_i2c_driver/circuitpython_i2c_transceiver.py

@@ -0,0 +1,48 @@
+from adafruit_bus_device.i2c_device import I2CDevice
+from .transceiver_v1 import I2cTransceiverV1
+import time
+
+class CircuitPythonI2cTransceiver(I2cTransceiverV1):
+    def __init__(self, i2c, device_address):
+        super(CircuitPythonI2cTransceiver, self).__init__()
+        self._device = I2CDevice(i2c, device_address)
+
+    @property
+    def description(self):
+        return "CircuitPython I2C Transceiver"
+
+    def transceive(self, slave_address, tx_data, rx_length, read_delay, timeout):
+        error = None
+        status = self.STATUS_OK
+        try:
+            if tx_data is not None:
+                self.write(tx_data)
+        except OSError as e:
+            status = self.STATUS_UNSPECIFIED_ERROR
+            error = e
+        
+        if read_delay > 0:
+            time.sleep(read_delay)
+        if(status == self.STATUS_OK):
+            try:
+                if rx_length is not None:
+                    return status, error, self.read(rx_length)
+            except OSError as e:
+                status = self.STATUS_UNSPECIFIED_ERROR
+                error = e
+        
+        return status, error, bytearray(b"")
+
+
+    def write(self, data):
+        data_bytes = bytearray(data) if isinstance(data, (bytes, bytearray, list, tuple)) else bytearray()
+        if(len(data_bytes) == 0):
+            return
+        with self._device as i2c_device:
+            i2c_device.write(data_bytes)
+
+    def read(self, count):
+        read_buffer = bytearray(count)
+        with self._device as i2c_device:
+            i2c_device.readinto(read_buffer)
+        return read_buffer