Add new module for sensor adxl345 (#223)

* Add module adxl345
* Add ADXL345 to README.md
---------
Co-authored-by: Benji <46675043+BenjiU@users.noreply.github.com>

README.md

@@ -41,6 +41,7 @@ Hardware support is provided by specific GPIO, Sensor and Stream modules. It's e
   - INA219 DC current sensor (`ina219`)
   - LM75 temperature sensor (`lm75`)
   - MCP3008 analog to digital converter (`mcp3008`)
+  - ADXl345 3-axis accelerometer up to ±16g  (`adxl345`)
 
 ### Streams
 

mqtt_io/modules/sensor/adxl345.py

@@ -0,0 +1,68 @@
+"""
+ADXL345 Digital Accelerometer Sensor
+
+Mandatory:
+- chip_addr
+
+Optional:
+- output_g (set True if output in g). default:m*s²
+
+Output:
+- x (in m*s²)
+- y (in m*s²)
+- z (in m*s²)
+"""
+
+from json import dumps
+from typing import cast
+
+from ...types import CerberusSchemaType, ConfigType, SensorValueType
+from . import GenericSensor
+
+REQUIREMENTS = ("adxl345",)
+CONFIG_SCHEMA: CerberusSchemaType = {
+    "chip_addr": dict(type="integer", required=True, empty=False),
+    "output_g": dict(type="boolean", required=False, empty=False),
+}
+
+
+class Sensor(GenericSensor):
+    """
+    Implementation of Sensor class for the ADXL345 sensor.
+    """
+
+    SENSOR_SCHEMA: CerberusSchemaType = {
+        "type": dict(
+            type="string",
+            required=False,
+            empty=False,
+            default="all",
+            allowed=["all", "x", "y", "z"],
+        )
+    }
+
+    def setup_module(self) -> None:
+        # pylint: disable=import-outside-toplevel,attribute-defined-outside-init
+        # pylint: disable=import-error,no-member
+        from adxl345 import ADXL345  # type: ignore
+
+        self.i2c_addr: int = self.config["chip_addr"]
+        self.adxl345 = ADXL345(self.i2c_addr)
+
+    def get_value(self, sens_conf: ConfigType) -> SensorValueType:
+        sens_type = sens_conf["type"]
+
+        if "output_g" in self.config and self.config["output_g"]:
+            all_axes = self.adxl345.get_axes(True)
+        else:
+            all_axes = self.adxl345.get_axes()
+
+        return cast(
+            float,
+            dict(
+                x=all_axes["x"],
+                y=all_axes["y"],
+                z=all_axes["z"],
+                all_axes=dumps(all_axes),
+            )[sens_type],
+        )