add py aqi_monitor implementation

aqi_monitor_py/README.md

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+# Python Sensor Application
+Updated script running on a RaspberryPi. Pure python implementation.
+
+## Install libraries
+```
+pip install -r requirements.txt
+```

aqi_monitor_py/requirements.txt

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+ipython
+simple-sds011
+requests
+RPi.bme280
+
+cffi
+smbus-cffi

aqi_monitor_py/sensor/config.sample.json

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+{
+    "url": "https://www.example.com/api/aqi",
+    "username": "username",
+    "password": "password"
+}

aqi_monitor_py/sensor/main.py

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+"""entry point to collect data from sensors"""
+
+import json
+import sys
+
+from os import path
+
+import requests
+
+from sensor_sds011 import SDS
+from sensor_bme280 import BmeSensor
+
+
+class PiSensor:
+    """collect and send data"""
+
+    SENSOR_ID = 1
+
+    def __init__(self):
+        self.data = False
+
+    def get_data(self):
+        """get all data from sensors"""
+        self.data = {}
+        self.get_sds011()
+        self.get_bme()
+        self.add_static()
+
+    def get_sds011(self):
+        """get data dict from sds011"""
+        sds_data = SDS().collect()
+        self.data.update(sds_data)
+
+    def get_bme(self):
+        """get data dict from bme"""
+        bme_data = BmeSensor().collect()
+        self.data.update(bme_data)
+
+    def add_static(self):
+        """add static values to data"""
+        self.data.update(
+            {
+                "sensor_id": self.SENSOR_ID,
+                "uptime": self.get_uptime(),
+            }
+        )
+
+    @staticmethod
+    def get_uptime():
+        """read uptime"""
+        with open("/proc/uptime", "r", encoding="utf-8") as f:
+            uptime_seconds = float(f.readline().split()[0])
+
+        return uptime_seconds
+
+    def send_data(self):
+        """post data to api endpoint"""
+        config = self.read_config()
+        auth = (config["username"], config["password"])
+        response = requests.post(config["url"], json=self.data, auth=auth)
+        if not response.ok:
+            print(response.text)
+
+    def read_config(self):
+        """read config file"""
+        # build path
+        root_folder = path.dirname(sys.argv[0])
+        if root_folder == '/sbin':
+            # running interactive
+            config_path = 'config.json'
+        else:
+            config_path = path.join(root_folder, 'config.json')
+
+        with open(config_path, "r", encoding="utf-8") as f:
+            config = json.loads(f.read())
+
+            return config
+
+
+if __name__ == "__main__":
+    sensor = PiSensor()
+    sensor.get_data()
+    print(sensor.data)
+    sensor.send_data()

aqi_monitor_py/sensor/sensor_bme280.py

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+"""interact with temperature sensor"""
+# pylint: disable=import-error
+
+import smbus2
+import bme280
+
+
+class BmeSensor:
+    """interact with BME280 sensor on pi"""
+
+    PORT = 1
+    ADDRESS = 0x76
+
+    def __init__(self):
+        self.data = False
+
+    def collect(self):
+        """collect"""
+        print("collect data from bme280")
+        self.get_data()
+        temperature_values = self.format_data()
+        print(f"bme280 data: {temperature_values}")
+
+        return temperature_values
+
+    def get_data(self):
+        """read data from sensor"""
+        bus = smbus2.SMBus(self.PORT)
+        calibration_params = bme280.load_calibration_params(bus, self.ADDRESS)
+        self.data = bme280.sample(bus, self.ADDRESS, calibration_params)
+
+    def format_data(self):
+        """build dict to send"""
+        temperature_values = {
+            "temperature": round(self.data.temperature, 2),
+            "pressure": round(self.data.pressure),
+            "humidity": round(self.data.humidity, 2),
+        }
+
+        return temperature_values

aqi_monitor_py/sensor/sensor_sds011.py

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+"""interact with aqi and environment sensors on pi4"""
+import os
+from time import sleep
+import simple_sds011  # pylint: disable=import-error
+
+
+class SDS:
+    """collect data from sds011 sensor"""
+
+    def __init__(self):
+        self.port = self.get_port()
+        self.pm = simple_sds011.SDS011(self.port)
+
+    def collect(self):
+        """collect average values"""
+        print("start collect")
+        self.startup()
+        pm_values = self.query_sensor()
+        self.shutdown()
+        print(f"pm_values: {pm_values}")
+        print("finish collect")
+
+        return pm_values
+
+    def get_port(self):
+        """find tty port for sds sensor"""
+        print("find usb port")
+        usbs = [i for i in os.listdir("/dev/") if i.startswith("ttyUSB")]
+        if len(usbs) > 1:
+            raise ValueError(f"too many ttyUSBs found: {usbs}")
+
+        port = f"/dev/{usbs[0]}"
+
+        return port
+
+    def startup(self):
+        """activate and set mode"""
+        print("startup sensor")
+        self.pm.active = 1
+        sleep(0.5)
+        self.pm.mode = simple_sds011.MODE_PASSIVE
+        print("warm up")
+        sleep(20)
+
+    def query_sensor(self):
+        """query 15 times"""
+        print("collect samples")
+        pm25_sample = []
+        pm10_sample = []
+
+        for _ in range(15):
+            response = self.pm.query()
+            pm25, pm10 = response.get("value").values()
+
+            pm25_sample.append(pm25)
+            pm10_sample.append(pm10)
+
+            sleep(1)
+
+        print(pm25_sample)
+        print(pm10_sample)
+        pm25_avg = self.avg(pm25_sample)
+        pm10_avg = self.avg(pm10_sample)
+
+        pm_values = {
+            "pm25": pm25_avg,
+            "pm10": pm10_avg
+        }
+
+        return pm_values
+
+    def shutdown(self):
+        """deactivate"""
+        print("shutdown sensor")
+        self.pm.active = 0
+
+    @staticmethod
+    def avg(lst):
+        """calc average of list"""
+        return round(sum(lst) / len(lst), 1)

aqi_monitor_py/service/sensor.service

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+[Unit]
+Description=sensor main.py
+
+[Service]
+User=simon
+Group=simon
+Type=oneshot
+ExecStart=python /home/simon/aqi_monitor/aqi_monitor_py/sensor/main.py

aqi_monitor_py/service/sensor.timer

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+[Unit]
+Description=sensor main.py
+
+[Timer]
+OnBootSec=1min
+OnUnitActiveSec=3min
+
+[Install]
+WantedBy=multi-user.target