Add VEML7700 Light Level Sensor (#398)

* Add VEML7700 Light Level Sensor
* Set lux_corrected if < 1000

Author: mschlenstedt

README.md

@@ -48,6 +48,7 @@ Hardware support is provided by specific GPIO, Sensor and Stream modules. It's e
   - PMS5003 particulate sensor (`pms5003`)
   - SHT40/SHT41/SHT45 temperature and humidity sensors (`sht4x`)
   - TLSl2561 light level sensor (`tsl2561`)
+  - VEML7700 light level sensor (`veml7700`)
   - YF-S201 flow rate sensor (`yfs201`)
 
 

mqtt_io/modules/sensor/veml7700.py

@@ -0,0 +1,109 @@
+"""
+VEML7700 luminosity sensor
+"""
+from typing import cast
+
+from ...types import CerberusSchemaType, ConfigType, SensorValueType
+from . import GenericSensor
+
+REQUIREMENTS = ("adafruit-circuitpython-veml7700",)
+CONFIG_SCHEMA: CerberusSchemaType = {
+    "chip_addr": {
+        "type": 'integer',
+        "required": False,
+        "empty": False,
+        "default": '0x10'},
+    "integration_time": {
+        "required": False,
+        "empty": False,
+        "allowed": [25, 50, 100, 200, 400, 800],
+        "default": 25,
+    },
+    "gain": {
+        "required": False,
+        "empty": False,
+        "allowed": [0.125, 0.25, 1, 2],
+        "default": 0.125,
+    },
+}
+
+
+class Sensor(GenericSensor):
+    """
+    Implementation of Sensor class for the Adafruit_VEML7700
+    """
+
+    SENSOR_SCHEMA: CerberusSchemaType = {
+        "type": {
+            "type": 'string',
+            "required": False,
+            "empty": False,
+            "allowed": ['light', 'lux', 'lux_corrected'],
+            "default": 'lux_corrected',
+        },
+    }
+
+    def setup_module(self) -> None:
+        # pylint: disable=import-outside-toplevel,attribute-defined-outside-init
+        # pylint: disable=import-error,no-member
+        import board  # type: ignore
+        import busio  # type: ignore
+        import adafruit_veml7700 # type: ignore
+        # Create the I2C bus
+        self.i2c = busio.I2C(board.SCL, board.SDA)
+
+        # Convert sensor address from hex to dec
+        self.address = int(0x10)
+        if self.config["chip_addr"]:
+            self.address = int(self.config["chip_addr"])
+
+        self.veml7700 = adafruit_veml7700.VEML7700(self.i2c, self.address)
+
+        # Set gain
+        gains = {
+            "0.125": 'ALS_GAIN_1_8',
+            "0.25": 'ALS_GAIN_1_4',
+            "1": 'ALS_GAIN_1',
+            "2": 'ALS_GAIN_2',
+        }
+        if 'gain' in self.config:
+            self.veml7700.light_gain = getattr(self.veml7700, gains[str(self.config['gain'])])
+
+        # Set integration time
+        ints = {
+            "25": 'ALS_25MS',
+            "50": 'ALS_50MS',
+            "100": 'ALS_100MS',
+            "200": 'ALS_200MS',
+            "400": 'ALS_400MS',
+            "800": 'ALS_800MS',
+        }
+        if 'integration_time' in self.config:
+            self.veml7700.light_integration_time = getattr(self.veml7700,
+                ints[str(self.config['integration_time'])])
+
+        #print("veml7700 Gain = {}".format(self.veml7700.light_gain))
+        #print("veml7700 Integration time = {}".format(self.veml7700.light_integration_time))
+
+    def get_value(self, sens_conf: ConfigType) -> SensorValueType:
+        # pylint: disable=import-outside-toplevel,attribute-defined-outside-init
+        # pylint: disable=import-error,no-member
+        sens_type = sens_conf["type"]
+        data = {
+            "light": self.veml7700.light,
+            "lux": self.veml7700.lux,
+            "lux_corrected": "-1",
+        }
+
+        if data['lux'] > 1000:
+            data['lux_corrected'] = (6.0135e-13 * data['lux'] ** 4) + \
+                (-9.3924e-9 * data['lux'] ** 3) + \
+                (8.1488e-5 * data['lux'] ** 2) + \
+                (1.0023 * data['lux'])
+        else:
+            data['lux_corrected'] = data['lux']
+
+        return cast(
+            float,
+            data[sens_type],
+        )