get_external_data.py

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

'''
Following script gets weather data from OpenWeathcerMap.org using 
JSON API 
Data acquisited:
- Pressure
- Wind speed
- Wind Direction
'''
import urllib2
import json
import sqlite3
import os
import Adafruit_BMP.BMP085 as BMP085
import sensor
import smbus

from openweatherconfig import config
from sensor_config import config as sensor_config

# define I2C bus number
I2C_BUS_NUMBER = 1

# define device address
LIGHT_SENSOR_ADDR = 0x13
BH1750FVI_ADDR = 0x23

def fetchJSON(url):
    req = urllib2.Request(url)
    response = urllib2.urlopen(req)
    return response.read()


def processData(json):
    out = {}

    sensor_handler = sensor.sensor()

    bmp_180_sensor = BMP085.BMP085()

    out['pressure'] = round(bmp_180_sensor.read_sealevel_pressure(35) / 100, 1)
    out['wind-direction'] = json["wind"]["deg"]
    out['wind-speed'] = json["wind"]["speed"]

    # FIXME this is a hack, whole process should be rewritten
    sensor_handler.save_value(2, round(bmp_180_sensor.read_sealevel_pressure(35) / 100, 1))
    sensor_handler.save_value(3, json["main"]["pressure"])
    sensor_handler.save_value(4, json["wind"]["speed"])
    sensor_handler.save_value(5, json["wind"]["deg"])
    sensor_handler.save_value(6, bmp_180_sensor.read_temperature()) # Save internal temperature readout
    return out

def saveSQLite(data):
    conn = sqlite3.connect(os.path.dirname(os.path.realpath(__file__)) + '/data.db')

    c = conn.cursor()
    c.execute('CREATE TABLE IF NOT EXISTS external_data(`Date` text, Pressure int, WindSpeed real, WindDirection int)')
    c.execute(
        "INSERT INTO external_data(`Date`, Pressure, WindSpeed, WindDirection) VALUES(datetime('now','localtime'), " + str(
            data['pressure']) + "," + str(data['wind-speed']) + "," + str(data['wind-direction']) + ")")

    conn.commit()
    conn.close()

def convertToNumber(data):
  return ((data[1] + (256 * data[0])) / 1.2)

def readLight(addr=BH1750FVI_ADDR):
  data = smbus.SMBus(I2C_BUS_NUMBER).read_i2c_block_data(addr,0x20)
  return convertToNumber(data)

def main():
    
    try:
        sWeather = fetchJSON("http://api.openweathermap.org/data/2.5/weather?q=" + config['location'] + "&units=metric&APPID=" + config['api'])
        jWeather = json.loads(sWeather)

        data = processData(jWeather)

        saveSQLite(data)
    except urllib2.HTTPError:
        print "Failed to connect to OpenWeathcerMap"
    
    if (sensor_config['attiny_light_meter'] == True):
        try:
            bus = smbus.SMBus(I2C_BUS_NUMBER)
            light_level = bus.read_byte(LIGHT_SENSOR_ADDR) * 256 + bus.read_byte(LIGHT_SENSOR_ADDR);
        
            sensor_handler = sensor.sensor()
            sensor_handler.save_value(7, light_level)
        except IOError as e:
            print "Failed to fetch light level"
    
    elif (sensor_config['BH1750FVI_light_meter'] == True):
        try:
            light_level = readLight();
        
            sensor_handler = sensor.sensor()
            sensor_handler.save_value(8, light_level)
        except IOError as e:
            print "Failed to fetch light level"
    
    
print "All data fetched"
    
if __name__ == "__main__":
    main()