init

.gitignore

@@ -0,0 +1,3 @@
+**/.DS_Store
+env
+*.pyc

Dockerfile

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+FROM python:3.8
+WORKDIR /code
+COPY src/requirements.txt .
+RUN pip install -r requirements.txt
+COPY src .
+ENTRYPOINT [ "python" ]
+CMD [ "app.py" ]

Makefile

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+PI_IP_ADDRESS=10.0.0.172
+PI_USERNAME=pi
+
+.PHONY: run
+run:
+	@docker-compose up
+
+.PHONY: install
+install:
+	@cd scripts && bash install.sh
+
+.PHONY: copy
+copy:
+	@rsync -a $(shell pwd) --exclude env $(PI_USERNAME)@$(PI_IP_ADDRESS):/home/$(PI_USERNAME)
+
+.PHONY: shell
+shell:
+	@ssh $(PI_USERNAME)@$(PI_IP_ADDRESS)
+
+.PHONY: build
+build:
+	@docker-compose build

README.md

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+# Raspberry Pi Air Quality Monitor
+A simple air quality monitoring service for the Raspberry Pi.
+
+## Installation
+Clone the repository and run the following:
+```bash
+make install
+```
+
+## Running
+To run, use the run command:
+```bash
+make run
+```
+
+## Architecture
+This project uses python, flask, docker-compose and redis to create a simple web server to display the latest historical values from the sensor.
+
+## Example Data
+Some example data you can get from the sensor includes the following:
+
+```json
+{
+    "device_id": 13358,
+    "pm10": 10.8,
+    "pm2.5": 4.8,
+    "timestamp": "2021-06-16 22:12:13.887717"
+}
+```
+
+The sensor reads two particulate matter (PM) values.
+
+PM10 is a measure of particles less than 10 micrometers, whereas PM 2.5 is a measurement of finer particles, less than 2.5 micrometers.
+
+Different particles are from different sources, and can be hazardous to different parts of the respiratory system.

docker-compose.yaml

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+version: "3.4"
+services:
+  redis:
+    image: redis
+    volumes:
+      - ./data/redis:/data
+  web:
+    build: .
+    image: pi-air-quality-monitor
+    devices:
+      - "/dev/ttyUSB0:/dev/ttyUSB0"
+    environment:
+        - REDIS_HOST=redis
+        - PORT=8000
+    volumes:
+      - ./src:/code
+    depends_on:
+      - "redis"
+    ports:
+      - "8000:8000"

scripts/install.sh

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+#!/bin/bash
+# install.sh
+
+cd ../
+
+sudo apt-get update
+sudo apt-get install -y python3 python3-pip python3-dev libffi-dev libssl-dev
+
+curl -sSL https://get.docker.com | sh
+sudo usermod -aG docker ${USER}
+sudo pip3 install docker-compose
+sudo systemctl enable docker
+newgrp docker

src/AirQualityMonitor.py

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+import json
+import os
+import time
+from sds011 import SDS011
+import redis
+
+redis_client = redis.StrictRedis(host=os.environ.get('REDIS_HOST'), port=6379, db=0)
+
+
+class AirQualityMonitor():
+
+    def __init__(self):
+        self.sds = SDS011(port='/dev/ttyUSB0')
+        self.sds.set_working_period(rate=1)
+
+    def get_measurement(self):
+        return {
+            'time': int(time.time()),
+            'measurement': self.sds.read_measurement(),
+        }
+
+    def save_measurement_to_redis(self):
+        """Saves measurement to redis db"""
+        redis_client.lpush('measurements', json.dumps(self.get_measurement(), default=str))
+
+    def get_last_n_measurements(self, n=10):
+        """Returns the last n measurements in the list"""
+        return [json.loads(x) for x in redis_client.lrange('measurements', -n, -1)]

src/app.py

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+import os
+import time
+from flask import Flask, request, jsonify, render_template
+from AirQualityMonitor import AirQualityMonitor
+from apscheduler.schedulers.background import BackgroundScheduler
+import redis
+import atexit
+from flask_cors import CORS, cross_origin
+
+
+
+app = Flask(__name__)
+cors = CORS(app)
+app.config['CORS_HEADERS'] = 'Content-Type'
+aqm = AirQualityMonitor()
+
+scheduler = BackgroundScheduler()
+scheduler.add_job(func=aqm.save_measurement_to_redis, trigger="interval", seconds=60)
+scheduler.start()
+atexit.register(lambda: scheduler.shutdown())
+
+
+def reconfigure_data(measurement):
+    """Reconfigures data for chart.js"""
+    current = int(time.time())
+    measurement = measurement.reverse()
+    return {
+        'labels': [int((current - (x['time'])) / 60) for x in measurement],
+        'pm10': {
+            'label': 'pm10',
+            'data': [x['measurement']['pm10'] for x in measurement],
+            'backgroundColor': '#cc0000',
+            'borderColor': '#cc0000',
+            'borderWidth': 3,
+        },
+        'pm2': {
+            'label': 'pm2.5',
+            'data': [x['measurement']['pm2.5'] for x in measurement],
+            'backgroundColor': '#42C0FB',
+            'borderColor': '#42C0FB',
+            'borderWidth': 3,
+        },
+    }
+
+@app.route('/')
+def index():
+    """Index page for the application"""
+    context = {
+        'historical': reconfigure_data(aqm.get_last_n_measurements()),
+    }
+    return render_template('index.html', context=context)
+
+
+@app.route('/api/')
+@cross_origin()
+
+def api():
+    """Returns historical data from the sensor"""
+    context = {
+        'historical': reconfigure_data(aqm.get_last_n_measurements()),
+    }
+    return jsonify(context)
+
+
+@app.route('/api/now/')
+def api_now():
+    """Returns latest data from the sensor"""
+    context = {
+        'current': aqm.get_measurement(),
+    }
+    return jsonify(context)
+
+
+if __name__ == "__main__":
+    app.run(debug=True, use_reloader=False, host='0.0.0.0', port=int(os.environ.get('PORT', '8000')))

src/requirements.txt

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+sds011==0.2.0
+ipython
+flask
+redis
+APScheduler==3.7.0
+flask-cors

src/templates/index.html

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+<!doctype html>
+<html lang="en">
+
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="description" content="">
+    <title>Raspberry Pi Air Quality Monitor</title>
+
+    <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet"
+        integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
+
+</head>
+<body>
+    <div class="container">
+        <div class="row">
+            <div class="col-12">
+                <h1>Raspberry Pi Air Quality Monitor</h1>
+            </div>
+        </div>
+        <div class="row">
+            <div class="col-12">
+                <canvas id="historicalChart" width="400" height="200"></canvas>
+            </div>
+        </div>
+    </div>
+    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"
+        integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous">
+    </script>
+    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
+
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.3.2/chart.min.js" integrity="sha512-VCHVc5miKoln972iJPvkQrUYYq7XpxXzvqNfiul1H4aZDwGBGC0lq373KNleaB2LpnC2a/iNfE5zoRYmB4TRDQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
+    <script>
+
+        $.getJSON('http://10.0.0.172:8000/api/', function(data) {
+            var ctx = document.getElementById('historicalChart').getContext('2d');
+            var historicalChart = new Chart(ctx, {
+                type: 'line',
+                data: {
+                    labels: data.historical.labels,
+                    datasets: [data.historical.pm10, data.historical.pm2]
+                },
+                options: {
+                    scales: {
+                        y: {
+                            beginAtZero: true
+                        }
+                    }
+                }
+            });
+        })
+
+
+        </script>
+
+
+
+</body>
+</html>