Internet of Things : Home Automation with RaspberryPi Python

Wednesday, October 2, 2013

Home Automation with RaspberryPi Python - Django

So after attending the 2 meet-ups for IOT-Pune. I got a Raspberry Pi and decided to play around with it a little bit. The following post will walk you through the steps needed to turn on/off a light bulb.

Things needed

1. Raspberry Pi

2. Relay switch

3. light bulb with wire to plug into main power supply

Lets us start!!!

sudo apt-get install python-dev python-setuptools

sudo pip install django

django-admin.py startproject mysite

cd mysite/

django-admin.py startapp ledblink

cd mysite

open file named setting.py and add the ledblink app in the INSTALLED_APPS so that it looks like this

INSTALLED_APPS = (

'django.contrib.auth',

'django.contrib.contenttypes',

'django.contrib.sessions',

'django.contrib.sites',

'django.contrib.messages',

'django.contrib.staticfiles',

'ledblink',

# Uncomment the next line to enable the admin:

'django.contrib.admin',

# Uncomment the next line to enable admin documentation:

# 'django.contrib.admindocs',

)

add this to the templates dir make sure you add import os at the top of the page

TEMPLATE_DIRS = (

os.path.join(os.path.dirname(__file__), 'templates').replace('\\','/'),

# Put strings here, like "/home/html/django_templates" or "C:/www/django/templates".

# Always use forward slashes, even on Windows.

# Don't forget to use absolute paths, not relative paths.

)

cd ledblink
open the views.py file and change it to this

from django.shortcuts import render

from django.http import HttpResponse

import RPi.GPIO as GPIO

import time

GPIO.setmode(GPIO.BOARD)

GPIO.setup(18,GPIO.OUT)

def blinker(request):

if 'on' in request.POST:

GPIO.output(18,1)

elif 'off' in request.POST:

GPIO.output(18,0)

return render(request,'control_page.html')

Let us add the template control pages so go ahead and create a templates directory in your ledblink app and add the following html code and name it control_page.html

<!DOCTYPE html>

<html>

<head>

</head>

<body>

<form action="" method="post">{% csrf_token %}

</form>

</body>

</html>

now let us create a url that links to this view. Goto the urls.py file in mysite directory cd ../mysite

from django.conf.urls import patterns, include, url

from ledblink.views import blinker

# Uncomment the next two lines to enable the admin:

# from django.contrib import admin

# admin.autodiscover()

urlpatterns = patterns('',

url(r'^ledblink/$',blinker),

# Examples:

# url(r'^$', 'mysite.views.home', name='home'),

# url(r'^mysite/', include('mysite.foo.urls')),

# Uncomment the admin/doc line below to enable admin documentation:

# url(r'^admin/doc/', include('django.contrib.admindocs.urls')),

# Uncomment the next line to enable the admin:

# url(r'^admin/', include(admin.site.urls)),

)

Goto main folder of the project where the manage.py file is located and run the following command

sudo python manage.py runserver 192.168.0.106:8000

open up a web browser and type http://192.168.0.106:8000/ledblink/ in the address bar and you should have the following result

now lets get to the part where we connect every thing to the raspberry pi.

Sorry I couldn't get a better picture even though Nishant suggested to take the book out. :P But yoy connect the 5V out of the Pi that is pin 2 to the positive on the relay . The ground pin 6 to the regative of the relay and finaly GPIO18 to the corresponding pin on the relay board.