Merge pull request #1 from supersciencechris/ds18b20_sensor

Ds18b20 sensor (see: mudpi#42 (comment))

Author: SpaceCaseChris

mudpi/extensions/ds18b20/__init__.py

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+""" 
+    DS18B20 Extension
+    Includes sensor interface for DS18B20.
+    Works for Dallas 1-wire temperature sensors.
+"""
+from mudpi.extensions import BaseExtension
+
+
+class Extension(BaseExtension):
+    namespace = 'ds18b20'
+    update_interval = 60
+

mudpi/extensions/ds18b20/docs.html

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+# DS18B20
+The `ds18b20` extension connects to a DS18B20 device to gather temperature readings. The sensor will return `temperature`.
+
+This extension does not take an extension level configs and is focused on [interfaces.]({{url('docs/developers-interfaces')}})
+
+---
+<div class="mb-2"></div>
+
+## Sensor Interface
+Provides a [sensor]({{url('docs/sensors')}}) that returns a DS18B20 readings. 
+
+<table class="mt-2 mb-4">
+<thead><tr><td width="15%">Option</td><td width="15%">Type</td><td width="15%">Required</td><td width="55%">Description</td></tr></thead>
+<tbody>
+    <tr><td class="font-600">key</td><td class="text-italic text-sm">[String]</td><td>Yes</td><td class="text-xs">Unique slug id for the component</td></tr>
+    <tr><td class="font-600">name</td><td class="text-italic text-sm">[String]</td><td>No</td><td class="text-xs">Friendly display name of component. Useful for UI.</td></tr>
+    <tr><td class="font-600">one_wire_ID</td><td class="text-italic text-sm">[String]</td><td>No</td><td class="text-xs">The address of the DS18B20 sensor. This should be set if using mulitple DS18B20 sensors and can be found as a directory in `/sys/bus/w1/devices/`  in the format of `28-XXXXXXXXXXXXX` . <strong>Default 10</strong></td></tr>
+</tbody>
+</table>
+
+### Config Examples
+Here is a config of a complete example sensor.
+
+```json
+"sensor": [{
+    "key": "ds18b20_outside",
+    "interface": "ds18b20",
+    "name": "Outside temperature",
+    "one_wire_ID": "28-0000000000001"
+}]
+```
+
+### Data
+Here is an example of the data returned by the DS18B20:
+
+```json
+{
+    "temperature": 50
+}
+```
+---

mudpi/extensions/ds18b20/extension.json

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+{
+	"name": "DS18B20 1-Wire Temperature Sensor",
+	"namespace": "ds18b20",
+	"details": {
+		"description": "Provides interface for ds18b20 sensors to take tempurature readings.",
+		"documentation": "https://mudpi.app/docs/sensors/ds18b20"
+	},
+	"requirements": ["glob2", "python-time"]
+}

mudpi/extensions/ds18b20/sensor.py

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+"""
+    DS18B20 Sensor Interface
+    Connects to a DS18B20 device to get
+    temperature readings.
+"""
+import os
+import glob
+import time
+
+from mudpi.constants import METRIC_SYSTEM
+from mudpi.extensions import BaseInterface
+from mudpi.extensions.sensor import Sensor
+from mudpi.logger.Logger import Logger, LOG_LEVEL
+from mudpi.exceptions import MudPiError, ConfigError
+
+os.system('modprobe w1-gpio')
+os.system('modprobe w1-therm')
+
+
+#device_folder = '/sys/bus/w1/devices/28-XXXXXXXXXXXXX'
+#device_folder = glob.glob(base_dir + '/28*')[0]
+#device_file = device_folder + '/w1_slave'
+
+class Interface(BaseInterface):
+    
+    def load(self, config):
+        """ Load DS18B20 sensor component from configs """
+        sensor = ds18b20(self.mudpi, config)
+        self.add_component(sensor)
+        return True
+
+    def validate(self, config):
+        if not isinstance(config, list):
+            config = [config]
+
+        for conf in config:
+            """ See if 1-wire ID was passed by the user in the config file """
+            if not conf.get('one_wire_ID'):
+                Logger.log(
+                    LOG_LEVEL["debug"],
+                    'DS18B20 one_wire_ID not set. Will search for device.'
+                )         
+               
+        return config
+
+class ds18b20(Sensor):
+    """ DS18B20 Sensor get readings temperature. """
+
+    """ Properties """
+    @property
+    def id(self):
+        """ Return a unique id for the component """
+        return self.config['key']
+
+    @property
+    def name(self):
+        """ Return the display name of the component """
+        return self.config.get('name') or f"{self.id.replace('_', ' ').title()}"
+
+    @property
+    def state(self):
+        """ Return the state of the component (from memory, no IO!) """
+        return self._state
+
+    @property
+    def classifier(self):
+        """ Classification further describing it, effects the data formatting """
+        return 'temperature'
+
+    @property
+    def one_wire_ID(self):
+        return self.config['one_wire_ID']
+
+
+    """ Methods """
+    def init(self):
+        """To support multiple 1-wire devices check to see if the ID is set in the config.
+        If the ID is not set, there should only be a single 28-xxxxxxxxx directory in the base directory, so we use that. """
+
+        base_dir = '/sys/bus/w1/devices'
+
+        if self.config.get('one_wire_ID') and os.path.isdir(base_dir + '/' + self.config.get('one_wire_ID')):
+            self.device_file = base_dir + '/' + self.config.get('one_wire_ID') + '/w1_slave'
+            Logger.log(
+                LOG_LEVEL["debug"],
+                'Setting device file to ' + self.device_file
+            )
+        else:
+            Logger.log(
+                LOG_LEVEL["debug"],
+                'DS18B20 one_wire_ID not set or not found.'
+            )
+            """ Make sure 1-wire device directory exists """
+            try:
+                device_folder = glob.glob(base_dir + '/28*')[0]
+            except:
+                Logger.log(
+                    LOG_LEVEL["error"],
+                    'Failed to find 1-wire device directory. Ensure device is connected and one_wire_ID corret..'
+                    )
+            else:
+                self.device_file = device_folder + '/w1_slave'        
+        return True
+
+    def update(self):
+
+        def read_temp_raw():
+            f = open(self.device_file, 'r')
+            lines = f.readlines()
+            f.close()
+            return lines
+
+        lines = read_temp_raw()
+        while lines[0].strip()[-3:] != 'YES':
+            time.sleep(0.2)
+            lines = read_temp_raw()
+        equals_pos = lines[1].find('t=')
+        if equals_pos != -1:
+            temp_string = lines[1][equals_pos+2:]
+            temperature_c = float(temp_string) / 1000.0
+            temperature_f = temperature_c * 9.0 / 5.0 + 32.0
+            _temperature = round(temperature_c if self.mudpi.unit_system == METRIC_SYSTEM else temperature_f, 2)
+            readings = {
+                'temperature': _temperature,
+            }
+            self._state = readings
+            return readings
+        else:
+            Logger.log(
+                LOG_LEVEL["error"],
+                'Failed to get reading [DS18B20]. Try again!'
+            )
+        return None