Add support for veml6075 sensors. (#376)

* Add support for veml6075 sensors.

mqtt_io/modules/sensor/veml6075.py

@@ -0,0 +1,90 @@
+"""
+VEML 6075 UV sensor
+"""
+
+import logging
+from mqtt_io.types import ConfigType, SensorValueType
+from . import GenericSensor
+
+REQUIREMENTS = ("smbus2", "veml6075",)
+
+CONFIG_SCHEMA = {
+    "i2c_bus_num": {"type": "integer", "required": True, "empty": False},
+}
+
+
+# UV COEFFICIENTS AND RESPONSIVITY
+# More details here :
+# https://web.archive.org/web/20190416120825/http://www.vishay.com/docs/84339/designingveml6075.pdf
+# For more details
+##################################################################################
+# Configuration                #  a   #   b  #  c   #  d  #  UVAresp  # UVBresp  #
+##################################################################################
+# No teflon (open air)         # 2.22 # 1.33 # 2.95 # 1.74 # 0.001461 # 0.002591 #
+# 0.1 mm teflon 4.5 mm window  # 2.22 # 1.33 # 2.95 # 1.74 # 0.002303 # 0.004686 #
+# 0.1 mm teflon 5.5 mm window  # 2.22 # 1.33 # 2.95 # 1.74 # 0.002216 # 0.005188 #
+# 0.1 mm teflon 10 mm window   # 2.22 # 1.33 # 2.95 # 1.74 # 0.002681 # 0.004875 #
+# 0.25 mm teflon 10 mm window  # 2.22 # 1.33 # 2.95 # 1.74 # 0.002919 # 0.009389 #
+# 0.4 mm teflon 10 mm window   # 2.22 # 1.17 # 2.95 # 1.58 # 0.004770 # 0.006135 #
+# 0.7 mm teflon 10 mm window   # 2.22 # 1.17 # 2.95 # 1.58 # 0.007923 # 0.008334 #
+# 1.0 mm teflon 5.5 mm window  # 2.55 # 1.00 # 3.80 # 1.10 # 0.006000 # 0.003100 #
+##################################################################################
+
+_LOG = logging.getLogger(__name__)
+
+
+class Sensor(GenericSensor):
+    """
+    Implementation of Sensor class for the VEML 6075 UV sensor.
+    """
+
+    SENSOR_SCHEMA = {
+        "a": {"type": "float", "required": False, "empty": False, "default": 2.22},
+        "b": {"type": "float", "required": False, "empty": False, "default": 1.33},
+        "c": {"type": "float", "required": False, "empty": False, "default": 2.95},
+        "d": {"type": "float", "required": False, "empty": False, "default": 1.74},
+        "UVAresp": {"type": "float", "required": False, "empty": False, "default": 0.001461},
+        "UVBresp": {"type": "float", "required": False, "empty": False, "default": 0.002591},
+    }
+
+    def setup_module(self) -> None:
+        # pylint: disable=import-outside-toplevel,import-error
+        from smbus2 import SMBus  # type: ignore
+        from veml6075 import VEML6075  # type: ignore
+
+        self.bus = SMBus(self.config["i2c_bus_num"])
+        self.sensor = VEML6075(i2c_dev=self.bus)
+        self.sensor.set_shutdown(True)
+        self.sensor.set_high_dynamic_range(False)
+        self.sensor.set_integration_time('100ms')
+        self.sensor.set_shutdown(False)
+
+
+    def calculate_uv_index(self, sens_conf: ConfigType, \
+        uva: float, uvb: float, uv_comp1: float, uv_comp2: float) -> float:
+
+        """
+        Calculate the UV index from received values.
+        """
+
+        _LOG.debug("UVA: %f UVB: %f UV_comp1: %f UV_comp2: %f)", uva, uvb, uv_comp1, uv_comp2)
+        uva_calc = uva - (sens_conf["a"] * uv_comp1) - (sens_conf["b"] * uv_comp2)
+        uvb_calc = uvb - (sens_conf["c"] * uv_comp1) - (sens_conf["d"] * uv_comp2)
+        _LOG.debug("uva_calc: %f uvb_calc: %f", uva_calc, uvb_calc)
+        uva_index = uva_calc * sens_conf["UVAresp"]
+        uvb_index = uvb_calc * sens_conf["UVBresp"]
+        _LOG.debug("uva_index: %f uvb_index: %f", uva_index, uvb_index)
+        uv_index: float = (uva_index + uvb_index) / 2.0
+        return uv_index
+
+    def get_value(self, sens_conf: ConfigType) -> SensorValueType:
+        """
+        Get the UV index from the sensor
+        """
+
+        # Fetch the values
+        uva, uvb = self.sensor.get_measurements()
+        uv_comp1, uv_comp2 = self.sensor.get_comparitor_readings()
+
+        # Calculate and return the UV index
+        return self.calculate_uv_index(sens_conf, uva, uvb, uv_comp1, uv_comp2)