appDhtWebHistCam.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#  appDhtWebHistCam.py

'''
	RPi WEb Server for DHT captured data with Gage and Graph plot and Streeming video 
'''

# Raspberry Pi camera module (requires picamera package)
from camera_pi import Camera

from datetime import datetime

from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
from matplotlib.figure import Figure
import io

from flask import Flask, render_template, send_file, make_response, request, Response
app = Flask(__name__)

import sqlite3
conn=sqlite3.connect('../sensorsData.db')
curs=conn.cursor()

# Retrieve LAST data from database
def getLastData():
	for row in curs.execute("SELECT * FROM DHT_data ORDER BY timestamp DESC LIMIT 1"):
		time = str(row[0])
		temp = row[1]
		hum = row[2]
	#conn.close()
	return time, temp, hum

# Get 'x' samples of historical data
def getHistData (numSamples):
	curs.execute("SELECT * FROM DHT_data ORDER BY timestamp DESC LIMIT "+str(numSamples))
	data = curs.fetchall()
	dates = []
	temps = []
	hums = []
	for row in reversed(data):
		dates.append(row[0])
		temps.append(row[1])
		hums.append(row[2])
		temps, hums = testeData(temps, hums)
	return dates, temps, hums

# Test data for cleanning possible "out of range" values
def testeData(temps, hums):
	n = len(temps)
	for i in range(0, n-1):
		if (temps[i] < -10 or temps[i] >50):
			temps[i] = temps[i-2]
		if (hums[i] < 0 or hums[i] >100):
			hums[i] = temps[i-2]
	return temps, hums


# Get Max number of rows (table size)
def maxRowsTable():
	for row in curs.execute("select COUNT(temp) from  DHT_data"):
		maxNumberRows=row[0]
	return maxNumberRows

# Get sample frequency in minutes
def freqSample():
	times, temps, hums = getHistData (2)
	fmt = '%Y-%m-%d %H:%M:%S'
	tstamp0 = datetime.strptime(times[0], fmt)
	tstamp1 = datetime.strptime(times[1], fmt)
	freq = tstamp1-tstamp0
	freq = int(round(freq.total_seconds()/60))
	return (freq)

			
# Define and Initialize global variables
global numSamples
numSamples = maxRowsTable()
if (numSamples > 101):
	numSamples = 100

global freqSamples
freqSamples = freqSample()

global rangeTime
rangeTime = 100


# main route 
@app.route("/")
def index():
	time, temp, hum = getLastData()
	templateData = {
	  'time'		: time,
      'temp'		: temp,
      'hum'			: hum,
      'freq'		: freqSamples,
      'rangeTime'		: rangeTime
	}
	return render_template('index.html', **templateData)


@app.route('/', methods=['POST'])
def my_form_post():
    global numSamples 
    global freqSamples
    global rangeTime
    rangeTime = int (request.form['rangeTime'])
    if (rangeTime < freqSamples):
        rangeTime = freqSamples + 1
    numSamples = rangeTime//freqSamples
    numMaxSamples = maxRowsTable()
    if (numSamples > numMaxSamples):
        numSamples = (numMaxSamples-1)
    
    time, temp, hum = getLastData()
    
    templateData = {
	  'time'		: time,
      'temp'		: temp,
      'hum'			: hum,
      'freq'		: freqSamples,
      'rangeTime'	: rangeTime
	}
    return render_template('index.html', **templateData)
	
	
@app.route('/plot/temp')
def plot_temp():
	times, temps, hums = getHistData(numSamples)
	ys = temps
	fig = Figure()
	axis = fig.add_subplot(1, 1, 1)
	axis.set_title("Temperature [°C]")
	axis.set_xlabel("Samples")
	axis.grid(True)
	xs = range(numSamples)
	axis.plot(xs, ys)
	canvas = FigureCanvas(fig)
	output = io.BytesIO()
	canvas.print_png(output)
	response = make_response(output.getvalue())
	response.mimetype = 'image/png'
	return response

@app.route('/plot/hum')
def plot_hum():
	times, temps, hums = getHistData(numSamples)
	ys = hums
	fig = Figure()
	axis = fig.add_subplot(1, 1, 1)
	axis.set_title("Humidity [%]")
	axis.set_xlabel("Samples")
	axis.grid(True)
	xs = range(numSamples)
	axis.plot(xs, ys)
	canvas = FigureCanvas(fig)
	output = io.BytesIO()
	canvas.print_png(output)
	response = make_response(output.getvalue())
	response.mimetype = 'image/png'
	return response
	
@app.route('/camera')
def cam():
    """Video streaming home page."""
    return render_template('camera.html')


def gen(camera):
    """Video streaming generator function."""
    while True:
        frame = camera.get_frame()
        yield (b'--frame\r\n'
               b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')


@app.route('/video_feed')
def video_feed():
    """Video streaming route. Put this in the src attribute of an img tag."""
    return Response(gen(Camera()),
                    mimetype='multipart/x-mixed-replace; boundary=frame')


if __name__ == "__main__":
   app.run(host='0.0.0.0', port=80, debug=False)