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CPE-555 REAL TIME

EMBEDDED SYSTEM Weather Monitoring System using

Raspberry-Pi

By: Ankit R Bhansali

Drashti Sheth

Vaibhav Jindal

May 10, 2016

Stevens Institute of Technology

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Table of Contents Abstract .................................................................................................................. 3

Description of Components ................................................................................... 4

Ds18b20 temperature sensor…………………………………………………………………………5

DHT11 Temperature & Humidity Sensor………………………………………………………..5

BMP180 Barometer for atmosphere pressure and altitude……………………………6

Circuit Diagram……………………………………………………………………………………………………7

Configuration of Sensors……………………………………………………………………………………..8

DS18B……………………………………………………………………………………………………………8

DHT11……………………………………………………………………………………………………………8

BMP180…………………………………………………………………………………………………………9

Description of the Code ....................................................................................... 11

Testing and Results .............................................................................................. 17

References ............................................................................................................ 18

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ABSTRACT

In this project, we have designed a Weather Monitoring System using

Raspberry Pi and breadboard for sensing Temperature, Humidity and

Pressure using various sensors.

A Twitter Account is linked with the Weather Monitoring System which

will update the Temperature, Pressure and Humidity

The sensors are integrated with GPIOs using Raspberry Pi.

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Description of Components

Hardware components which we have used in our project are as below:

Raspberry-Pi

2- 10k ohm Resistors

Jumper wires

DS18B20 Temperature Sensor Probe

DHT11 Temperature & Humidity Sensor

BMP180 Barometer for atmosphere pressure and altitude.

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DS18B20 Temperature Sensor:

This is the latest DS18B20 1-Wire digital temperature sensor from Maxim IC.

It Reports degrees C with 9 to 12-bit precision, -55C to 125C (+/-0.5C).

Each sensor has a unique 64-Bit Serial number etched into it - allows for a huge

number of sensors to be used on one data bus.

This is a wonderful part that is the corner stone of many data-logging and

temperature control projects.

Moreover it requires no external components.

DHT11 Temperature & Humidity Sensor:

It is the multifunctional sensor that gives you temperature and relative humidity.

Sensor uses capacitive humidity sensor and thermistor to measure surrounding air.

It provides reliable readings when environmental humidity conditions in between

20% RH and 90% RH and temperature conditions between 0 – 50 degree Celsius.

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BMP180 Barometer for atmosphere pressure and altitude:

The BMP180 offers a pressure measuring range of 300 to 1100 hPa with an accuracy

down to 0.02 hPa in advanced resolution mode.

It’s based on piezo-resistive technology for high accuracy, ruggedness and long

term stability.

The chip only accepts 1.8V to 3.6V input voltage.

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Circuit Diagram

We implemented circuit on Raspberry-Pi as below by connecting all sensors,

resistor using jumper wires.

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Raspberry-Pi Layout

Configuration of Sensors

Configuring DHT11 Sensor:

Open the terminal and type the following commands:

• Take the terminal to the folder where your files are placed

• sudo su

• Python file_name.py

Configuring DS18B Sensor:

Open the command terminal and type the following commands:

• sudo modprobe w1-gpio

• Sudo moderate w1-therm

• cd/sys/bus/w1/devices

• ls

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• cd 28**********

• cat w1_slave

Configuring BMP180 Sensor:

• Connect it to 3.3V

• Also connect the i2c pin (SDA and SCL pin) to the SDA and SCL pin of

raspberry pi.

• Open the terminal and type the following commands:-

sudo i2cdetect -y 1

In the figure below, we can see our device connected

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Description of the Code

Below we have mention our python code and some of the screenshots of our code

for different sensors.

Code:

'''Rasproject:configuring the twitter part'''

#!/usr/bin/env python

import io

import numpy as np

import tweepy

import sys

import matplotlib

import random

matplotlib.use('Agg')

matplotlib.rcParams['timezone'] = 'America/New_York' # Replace with your time zone

import matplotlib.pyplot as plt

from pytz import timezone

import pytz

from matplotlib.dates import DateFormatter

from rasptemperature import read_temp

from temp import temperature

from ras1pressure import getpressure

from datetime import datetime

# Twitter API Keys

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CONSUMER_KEY = "'OXbOgWLrKxgWeAZEGEpezDqB7'

CONSUMER_SECRET = “not-shown-for-security-reasons”

ACCESS_KEY = '52004919-g03BuUSYtQHzN1NjHt8e4vZWhgFxZtAI9cqrEJT3c'

ACCESS_SECRET = “not-shown-for-security-reasons”

# Set file paths - Don't forget trailing slash

path_data_dir = "/home/pi/pathToDataDirectory/"

path_image_dir = "/home/pi/pathToImageDirectory/"

# Read the data file

## Plot humidity graph

data = np.genfromtxt(path_data_dir+'temp1.dat', delimiter=',')

dates = matplotlib.dates.epoch2num(data[:,0])

#dateshum = matplotlib.dates.epoch2num(datahumidity[:,1])

tempdata=data[:,1]

fig, ax = plt.subplots(figsize=(6,5))

ax.plot_date( dates, tempdata, ls='-', color='blue' )

ax.xaxis.set_major_formatter( DateFormatter('%m/%d/%y %H:%M'))

ax.set_ylabel('Temperature %')

for label in ax.get_xticklabels():

label.set_rotation(60)

plt.tight_layout()

plt.savefig(path_image_dir+'tempplot.png', bbox_inches='tight')

'''## Plot temperature graph

data = np.genfromtxt( path_data_dir+'temp1.dat', delimiter=',')

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dates = matplotlib.dates.epoch2num(data[:,0])

tempdata = data[:,1]

fig, ax = plt.subplots(figsize=(6,5))

ax.plot_date( dates, tempdata, ls='-', color='blue' )

ax.xaxis.set_major_formatter( DateFormatter('%d/%m/%y %H:%M'))

ax.set_ylabel('Temperature C')

for label in ax.get_xticklabels():

label.set_rotation(60)

plt.tight_layout()

plt.savefig(path_image_dir+'tempplot.png', bbox_inches='tight')'''

## Plot humidity graph

datahumidity = np.genfromtxt(path_data_dir+'humidity.dat', delimiter=',')

dateshum = matplotlib.dates.epoch2num(datahumidity[:,0])

tempdatahum = datahumidity[:,1]

fighum, axhum = plt.subplots(figsize=(6,5))

axhum.plot_date( dateshum, tempdatahum, ls='-', color='green' )

axhum.xaxis.set_major_formatter( DateFormatter('%m/%d/%y %H:%M'))

axhum.set_ylabel('Humidity %')

for label in axhum.get_xticklabels():

label.set_rotation(60)

plt.tight_layout()

plt.savefig(path_image_dir+'humidity.png', bbox_inches='tight')

## Plot combined graph of humidity and temperature to tweet using tweepy

figuremain = plt.figure(figsize=(8, 6), dpi=80)

ax = figuremain.add_subplot(211)

ax.plot_date( dates, tempdata, ls='-', color='blue' )

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ax.xaxis.set_major_formatter( DateFormatter('%m/%d/%y %H:%M'))

ax.set_ylabel('Temperature C')

for label in ax.get_xticklabels():

label.set_rotation(60)

axhum = figuremain.add_subplot(212)

axhum.plot_date( dateshum, tempdatahum, ls='-', color='green' )

axhum.xaxis.set_major_formatter( DateFormatter('%m/%d/%y %H:%M'))

axhum.set_ylabel('Humidity %')

for label in axhum.get_xticklabels():

label.set_rotation(60)

plt.tight_layout()

plt.savefig(path_image_dir+'combined.png', bbox_inches='tight')

# Get latest humidity value from file

file = open(path_data_dir+'Temp1.dat', 'r')

humval = file.read()

file.close()

# Get latest humidity value from file

file = open(path_data_dir+'humidity_val.dat', 'r')

humval = file.read()

file.close()

## Tweet or Print!

auth = tweepy.OAuthHandler(CONSUMER_KEY, CONSUMER_SECRET)

auth.set_access_token(ACCESS_KEY, ACCESS_SECRET)

api = tweepy.API(auth)

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tz = timezone("America/New_York")

ftime = datetime.now()

finaltime = tz.localize(ftime)

photo_path = path_image_dir+'combined.png'

cel = read_temp()[0]

temp = u"City:%.2f\u2103 | "%cel

status = "Hoboken:"+str(temperature)+" Humidity "+humval+"% - (EST)

"+finaltime.strftime('%m/%d/%Y %H:%M:%S')+" | Atmospheric pressure: "+getpressure()

status = status.encode('utf-8')

api.update_with_media(photo_path, status=status)

#print status

The code for Temperature sensor DS18B20

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The code for temperature sensor DHT11:

The Code for pressure and altitude sensor BMP180

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Testing and Results

These are screenshots of our testing and results. Here after running our code

and giving commands, we get results on our twitter account as you can see in

above pictures. We get temperature and humidity graph at particular time and also

values of pressure and altitude.

We have also attached our project working video with this. Here is the link where

you can watch video:

https://drive.google.com/a/stevens.edu/folderview?id=0ByPZz2nIbJrpWEpsb

kdFaFo5WVE&usp=sharing

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References

https://bhavyanshu.me/tutorials/circuit-diagram-and-code-snippet-of-my-

weather-monitoring-system/08/12/2015