''' FILE NAME lab_app.py Version 9 1. WHAT IT DOES This version adds support for Plotly. 2. REQUIRES * Any Raspberry Pi 3. ORIGINAL WORK Raspberry Full Stack 2015, Peter Dalmaris 4. HARDWARE * Any Raspberry Pi * DHT11 or 22 * 10KOhm resistor * Breadboard * Wires 5. SOFTWARE Command line terminal Simple text editor Libraries: from flask import Flask, request, render_template, sqlite3 6. WARNING! None 7. CREATED 8. TYPICAL OUTPUT A simple web page served by this flask application in the user's browser. The page contains the current temperature and humidity. A second page that displays historical environment data from the SQLite3 database. The historical records can be selected by specifying a date range in the request URL. The user can now click on one of the date/time buttons to quickly select one of the available record ranges. The user can use Jquery widgets to select a date/time range. The user can explore historical data to Plotly for visualisation and processing. // 9. COMMENTS -- // 10. END ''' from flask import Flask, request, render_template import time import datetime import arrow app = Flask(__name__) app.debug = True # Make this False if you are no longer debugging @app.route("/") def hello(): return "Hello World!" @app.route("/lab_temp") def lab_temp(): import sys import Adafruit_DHT humidity, temperature = Adafruit_DHT.read_retry(Adafruit_DHT.AM2302, 17) temperature = temperature * 9/5.0 + 32 if humidity is not None and temperature is not None: return render_template("lab_temp.html",temp=temperature,hum=humidity) else: return render_template("no_sensor.html") @app.route("/lab_env_db", methods=['GET']) #Add date limits in the URL #Arguments: from=2015-03-04&to=2015-03-05 def lab_env_db(): temperatures, humidities, timezone, from_date_str, to_date_str = get_records() # Create new record tables so that datetimes are adjusted back to the user browser's time zone. time_adjusted_temperatures = [] time_adjusted_humidities = [] for record in temperatures: local_timedate = arrow.get(record[0], "YYYY-MM-DD HH:mm").to(timezone) time_adjusted_temperatures.append([local_timedate.format('YYYY-MM-DD HH:mm'), round(record[2],2)]) for record in humidities: local_timedate = arrow.get(record[0], "YYYY-MM-DD HH:mm").to(timezone) time_adjusted_humidities.append([local_timedate.format('YYYY-MM-DD HH:mm'), round(record[2],2)]) print "rendering lab_env_db.html with: %s, %s, %s" % (timezone, from_date_str, to_date_str) return render_template("lab_env_db.html", timezone = timezone, temp = time_adjusted_temperatures, hum = time_adjusted_humidities, from_date = from_date_str, to_date = to_date_str, temp_items = len(temperatures), query_string = request.query_string, #This query string is used #by the Plotly link hum_items = len(humidities)) def get_records(): import sqlite3 from_date_str = request.args.get('from',time.strftime("%Y-%m-%d 00:00")) #Get the from date value from the URL to_date_str = request.args.get('to',time.strftime("%Y-%m-%d %H:%M")) #Get the to date value from the URL timezone = request.args.get('timezone','Etc/UTC'); range_h_form = request.args.get('range_h',''); #This will return a string, if field range_h exists in the request range_h_int = "nan" #initialise this variable with not a number print "REQUEST:" print request.args try: range_h_int = int(range_h_form) except: print "range_h_form not a number" print "Received from browser: %s, %s, %s, %s" % (from_date_str, to_date_str, timezone, range_h_int) if not validate_date(from_date_str): # Validate date before sending it to the DB from_date_str = time.strftime("%Y-%m-%d 00:00") if not validate_date(to_date_str): to_date_str = time.strftime("%Y-%m-%d %H:%M") # Validate date before sending it to the DB print '2. From: %s, to: %s, timezone: %s' % (from_date_str,to_date_str,timezone) # Create datetime object so that we can convert to UTC from the browser's local time from_date_obj = datetime.datetime.strptime(from_date_str,'%Y-%m-%d %H:%M') to_date_obj = datetime.datetime.strptime(to_date_str,'%Y-%m-%d %H:%M') # If range_h is defined, we don't need the from and to times if isinstance(range_h_int,int): arrow_time_from = arrow.utcnow().replace(hours=-range_h_int) arrow_time_to = arrow.utcnow() from_date_utc = arrow_time_from.strftime("%Y-%m-%d %H:%M") to_date_utc = arrow_time_to.strftime("%Y-%m-%d %H:%M") from_date_str = arrow_time_from.to(timezone).strftime("%Y-%m-%d %H:%M") to_date_str = arrow_time_to.to(timezone).strftime("%Y-%m-%d %H:%M") else: #Convert datetimes to UTC so we can retrieve the appropriate records from the database from_date_utc = arrow.get(from_date_obj, timezone).to('Etc/UTC').strftime("%Y-%m-%d %H:%M") to_date_utc = arrow.get(to_date_obj, timezone).to('Etc/UTC').strftime("%Y-%m-%d %H:%M") conn = sqlite3.connect('lab_app.db') curs = conn.cursor() curs.execute("SELECT * FROM temperatures WHERE rDateTime BETWEEN ? AND ?", (from_date_utc.format('YYYY-MM-DD HH:mm'), to_date_utc.format('YYYY-MM-DD HH:mm'))) temperatures = curs.fetchall() curs.execute("SELECT * FROM humidities WHERE rDateTime BETWEEN ? AND ?", (from_date_utc.format('YYYY-MM-DD HH:mm'), to_date_utc.format('YYYY-MM-DD HH:mm'))) humidities = curs.fetchall() conn.close() return [temperatures, humidities, timezone, from_date_str, to_date_str] @app.route("/to_plotly", methods=['GET']) #This method will send the data to ploty. def to_plotly(): import plotly.plotly as py from plotly.graph_objs import * temperatures, humidities, timezone, from_date_str, to_date_str = get_records() # Create new record tables so that datetimes are adjusted back to the user browser's time zone. time_series_adjusted_tempreratures = [] time_series_adjusted_humidities = [] time_series_temprerature_values = [] time_series_humidity_values = [] for record in temperatures: local_timedate = arrow.get(record[0], "YYYY-MM-DD HH:mm").to(timezone) time_series_adjusted_tempreratures.append(local_timedate.format('YYYY-MM-DD HH:mm')) time_series_temprerature_values.append(round(record[2],2)) for record in humidities: local_timedate = arrow.get(record[0], "YYYY-MM-DD HH:mm").to(timezone) time_series_adjusted_humidities.append(local_timedate.format('YYYY-MM-DD HH:mm')) #Best to pass datetime in text #so that Plotly respects it time_series_humidity_values.append(round(record[2],2)) temp = Scatter( x=time_series_adjusted_tempreratures, y=time_series_temprerature_values, name='Temperature' ) hum = Scatter( x=time_series_adjusted_humidities, y=time_series_humidity_values, name='Humidity', yaxis='y2' ) data = Data([temp, hum]) layout = Layout( title="Temperature and Humidity in Clayton's Apartment", xaxis=XAxis( type='date', autorange=True ), yaxis=YAxis( title='Fahrenheit', type='linear', autorange=True ), yaxis2=YAxis( title='Percent', type='linear', autorange=True, overlaying='y', side='right' ) ) fig = Figure(data=data, layout=layout) plot_url = py.plot(fig, filename='lab_temp_hum') return plot_url def validate_date(d): try: datetime.datetime.strptime(d, '%Y-%m-%d %H:%M') return True except ValueError: return False if __name__ == "__main__": app.run(host='0.0.0.0', port=8080)