Gallery

Program Overview

This comprehensive course covers everything from understanding Single Board Computers to building web-controlled home automation systems. Each module builds on the previous one, ensuring you gain practical skills through real-world projects.

Project roadmap: we'll start with a simple LED blink project, then move to an LDR (light sensor) digital test, and finish with a small Automation project using Django to build a web interface and control logic.

Part 1: Raspberry Pi — Imager & VNC Setup

Download Raspberry Pi Imager

Open the official Raspberry Pi software download page and download the Raspberry Pi Imager for your OS:

https://www.raspberrypi.com/software/

Step-by-step: Flash OS using Raspberry Pi Imager

⚠️ Crucial: The imaging step will erase the selected SD card. If you select the wrong drive, you may lose data and must start the process again. Double-check the target drive before writing.

Run Raspberry Pi Imager you downloaded from the link above. You'll see three main buttons: CHOOSE DEVICE, CHOOSE OS, and CHOOSE STORAGE.

Raspberry Pi Imager - Initial Screen
Click CHOOSE DEVICE → select RASPBERRY PI 4 from the list.
Click CHOOSE OS → select RASPBERRY PI OS (64-BIT).
Click CHOOSE STORAGE → select your MicroSD card. Make sure the size and label match the card you intend to flash.
After selecting all three options, the NEXT button will become active. Click NEXT.
A dialog will appear asking "Would you like to apply OS customisation settings?" Click EDIT SETTINGS to configure:
- GENERAL tab:
  ⚠️ Crucial: This step requires you to carefully input the correct details for raspberry pi. If you made any mistake with the input and you are unable to login to raspberry pi, you will need to redo the entire formatting again with proper input.
  - Set hostname: Enter any name here but make sure to note this name down. Best to give a simple name.
  - Set username and password: Choose your username and password (Again give an easy name and password and note it down somewhere).
  - Configure wireless LAN: Enter your Wi-Fi SSID (network name) and password. Select your Wireless LAN country (e.g., "IN" for India)
  GENERAL Tab - Hostname, Username, and WiFi Configuration
- SERVICES tab:
  - Enable SSH
  - Select "Use password authentication" (recommended for beginners)
- OPTIONS tab: You can ignore this
Click SAVE at the bottom of the OS Customisation window.
You'll return to the confirmation dialog. Click YES to apply the settings.
Review settings carefully. When ready, click Write to start imaging. Warning: This will erase all data on the selected storage device! Wait until the process completes and shows success.
When finished, safely eject/remove the SD card from your computer and insert it into the Raspberry Pi's SD card slot.
Power up the Raspberry Pi by connecting the power supply. Wait approximately 5 minutes for first-boot tasks to complete (OS expansion, network connection, and service initialization). The Pi will automatically connect to your Wi-Fi network. While waiting, continue with VNC setup below.

VNC: Remote Desktop Access (RealVNC)

VNC allows you to access the Raspberry Pi's desktop remotely from your computer. We'll use RealVNC Viewer for this.

Download RealVNC Viewer

Download RealVNC Viewer for Windows from the official website:

https://www.realvnc.com/en/connect/download/vnc/

RealVNC Download Page

Install RealVNC Viewer

Run the downloaded RealVNC Viewer installer
Follow the installation wizard and accept the license agreement
Complete the installation and launch RealVNC Viewer

Create New VNC Connection

Open RealVNC"
Click on File menu at the top → select New connection... (or press Ctrl+N)
A Properties dialog will appear. Fill in the connection details:
- Address: Enter the hostname you set in Raspberry Pi Imager (e.g., name.local or the Pi's IP address like 192.168.1.123)
- Name: Give it a friendly identifier (e.g., "My Raspberry Pi" or "Pi 4")
- Labels: Optional - you can add labels to organize multiple connections
Important: The address must match exactly what you entered in the Raspberry Pi Imager settings:
- If you set hostname as "raspberrypi", use: raspberrypi.local
- If you set hostname as "mypi", use: mypi.local
- Or use the IP address if you know it: 192.168.x.x
Click OK to save the connection. It will now appear in your Address book.
To connect: Double-click the saved connection in the Address book. You'll be prompted for:
- Username: The username you set in Raspberry Pi Imager
- Password: The password you set in Raspberry Pi Imager

We will now move onto SSH so we can connect our RealVNC to Raspberry Pi

SSH Access to Raspberry Pi

SSH (Secure Shell) allows you to access your Raspberry Pi's command line remotely. This is essential for troubleshooting, enabling services like VNC, and managing your Pi without a desktop interface.

Connect via SSH from Windows Command Prompt

Open Command Prompt (CMD) on your Windows PC:
- Press Windows Key + R
- Type cmd and press Enter
Windows Command Prompt

Type the SSH connection command using the hostname and username you set in Raspberry Pi Imager:

ssh username@hostname.local

# Example: if username is "pi" and hostname is "raspberrypi"
ssh pi@raspberrypi.local

# Or if you know the IP address:
ssh username@192.168.1.123

When prompted with "Are you sure you want to continue connecting?", type yes and press Enter to accept the SSH fingerprint
Enter the password you set in the Raspberry Pi Imager advanced settings
Note: When typing your password, you won't see any characters appear on screen (no asterisks or dots). This is normal for security reasons. Just type your password and press Enter.
Once logged in successfully, you'll see the Raspberry Pi command prompt:

Using raspi-config Tool

Now that you're connected via SSH, you can use the raspi-config tool to configure your Raspberry Pi.

Run the Raspberry Pi configuration tool:
Open raspi-config
```
sudo raspi-config
```
The Raspberry Pi Software Configuration Tool interface will open:
Navigate to 3 Interface Options and press Enter:
- Use arrow keys (↑ ↓) to move up and down
- Press Enter to select
- Press Tab to move between Select/Finish buttons
Select VNC to enable VNC server:
When asked "Would you like the VNC Server to be enabled?", select Yes
You'll see a confirmation message "The VNC Server is enabled". Press Enter to continue
Press Tab to highlight <Finish> and press Enter to exit raspi-config

Open the saved VNC profile and connect

After enabling the VNC interface on the Pi and waiting for it to boot, open RealVNC Viewer and double-click the connection you saved earlier.

Double-click the saved profile in RealVNC Viewer.
If the Identity Check dialog appears ("Device not recognized"), review the catchphrase/signature and click Continue to trust this device. This only appears the first time you connect.
When prompted, enter the username and password you configured in Raspberry Pi Imager, then click OK or Sign in.
After authentication, the Raspberry Pi desktop will appear in the VNC Viewer window.

Open the terminal

Open the Raspberry Pi terminal (or SSH into the Pi). If using the desktop, press Ctrl+Alt+T or open Terminal from the menu.

Update the system packages

Update package lists and upgrade installed packages before starting the project:

sudo apt update
sudo apt upgrade -y
# Optional: install Thonny (recommended for beginners)
sudo apt install thonny -y
# Install GPIO helper libraries
sudo apt install python3-gpiozero python3-rpi.gpio -y

Note

In order to paste codes into raspberry pi, use ctrl+shift+v to paste the code.

Part 2: LED Blynk Project

Note

In order to paste codes into raspberry pi, use ctrl+shift+v to paste the code.

1) Open the Terminal

Open the Raspberry Pi terminal (or SSH into the Pi). If using the desktop, press Ctrl+Alt+T or open Terminal from the menu.

2) Create project

nano blink.py

3) LED Blynk Code

Paste or write the following code into blink.py

# LED blink
import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

LED_PIN = 17  # BCM 17

# Set up the pin as output
GPIO.setup(LED_PIN, GPIO.OUT)

try:
    while True:
        GPIO.output(LED_PIN, GPIO.HIGH)  # Turn LED ON
        time.sleep(1)
        GPIO.output(LED_PIN, GPIO.LOW)   # Turn LED OFF
        time.sleep(1)
except KeyboardInterrupt:
    pass
finally:
    GPIO.cleanup()

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

Raspberry Pi 4B - Connections

1) Pin Connections

2) LED Connection

Connect LED positive (longer leg) to GPIO17 through a resistor, and the negative leg to ground.

4) Run the code

python3 blink.py

Part 4: Automation (Django)

Note

In order to paste codes into raspberry pi, use ctrl+shift+v to paste the code.

We'll create a small Django app to control the LED and read the LDR. Follow the steps below on your Raspberry Pi inside the project folder.

1) Open the Terminal

Open the Raspberry Pi terminal (or SSH into the Pi). If using the desktop, press Ctrl+Alt+T or open Terminal from the menu.

2) Create project folder

mkdir pi_led

cd pi_led

3) Creating Virtual Environment

python -m venv venv

source venv/bin/activate

4) Install Django

pip install django

5) Updating pip

python -m pip install --upgrade pip

6) Install Raspberry Pi GPIO Libraries

pip install gpiozero

sudo apt update

sudo apt install -y python3-rpi.gpio

7) Create Django project

django-admin startproject pi_web .

8) Create Django app

python manage.py startapp control

9) Update `pi_web/settings.py`

Open the file and replace/add these sections exactly:

nano pi_web/settings.py

Then open file pi_web/settings.py

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/5.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'django-insecure-3t=_%gj)t$y)5uxx4fxlh-ai%529v!1ts2t0!-m-zpu47tr2*3'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = ['*']


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'control'
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
    'django.middleware.common.CommonMiddleware',
]

ROOT_URLCONF = 'pi_web.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
	'DIRS': [ BASE_DIR / 'control' / 'templates' ],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'pi_web.wsgi.application'


# Database
# https://docs.djangoproject.com/en/5.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}


# Password validation
# https://docs.djangoproject.com/en/5.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/5.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/5.2/howto/static-files/

STATIC_URL = 'static/'

# Default primary key field type
# https://docs.djangoproject.com/en/5.2/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
STATICFILES_DIRS = [ BASE_DIR / 'control' / 'static' ]

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

10) Configure URLs

Using your preferred editor, open pi_web/urls.py and edit

nano pi_web/urls.py

Then open file pi_web/urls.py

from django.urls import path, include

urlpatterns = [
    path('', include('control.urls')),
]

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

11) Create `control/urls.py`

Using your preferred editor, create control/urls.py and edit

nano control/urls.py

Then open control/urls.py

from django.urls import path
from . import views

urlpatterns = [
    path('', views.index, name='index'),
    path('api/state/', views.api_state),
    path('api/led/', views.api_led),
    path('api/auto/', views.api_auto),
]

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

12) Create GPIO hardware file

(Inverted LDR logic example)

Using your preferred editor, create control/gpio_hw.py and edit

nano control/gpio_hw.py

Then open control/gpio_hw.py

import threading, time
import RPi.GPIO as GPIO

LED_PIN = 17
LDR_PIN = 27

_state = {
    'led_on': False,
    'auto': False,
    'ldr_d0': 1,
    'stop': False
}

GPIO.setmode(GPIO.BCM)
GPIO.setup(LDR_PIN, GPIO.IN)
GPIO.setup(LED_PIN, GPIO.OUT)
GPIO.output(LED_PIN, GPIO.LOW)

def poll():
    while not _state['stop']:
        d0 = GPIO.input(LDR_PIN)   # YOUR MODULE: 1 = DARK, 0 = BRIGHT
        _state['ldr_d0'] = d0

        if _state['auto']:
            if d0 == 1:  # DARK → LED ON
                GPIO.output(LED_PIN, GPIO.HIGH)
                _state['led_on'] = True
            else:
                GPIO.output(LED_PIN, GPIO.LOW)
                _state['led_on'] = False
        
        time.sleep(0.2)

threading.Thread(target=poll, daemon=True).start()

def set_led(on):
    GPIO.output(LED_PIN, GPIO.HIGH if on else GPIO.LOW)
    _state['led_on'] = on

def set_auto(on):
    _state['auto'] = on

def get_state():
    return _state

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

13) Create views

Using your preferred editor, create control/views.py and edit

nano control/views.py

Then open control/views.py

from django.shortcuts import render
from django.http import JsonResponse
from . import gpio_hw

def index(request):
    return render(request, 'control/index.html')

def api_state(request):
    return JsonResponse(gpio_hw.get_state())

def api_led(request):
    action = request.GET.get('action')
    if action == 'on':
        gpio_hw.set_led(True)
    elif action == 'off':
        gpio_hw.set_led(False)
    return JsonResponse(gpio_hw.get_state())

def api_auto(request):
    mode = request.GET.get('mode')
    if mode == 'on':
        gpio_hw.set_auto(True)
    elif mode == 'off':
        gpio_hw.set_auto(False)
    return JsonResponse(gpio_hw.get_state())

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

14) Create templates

Using your preferred editor, create control/template/control/index.html and edit

mkdir -p control/templates/control

nano control/templates/control/index.html

<!DOCTYPE html>
<html>
<head>
  <title>Pi LED Control</title>

  <style>
    body {
      font-family: Arial, sans-serif;
      background: #f3f4f6;
      margin: 0;
      padding: 40px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    h1 {
      margin-bottom: 20px;
      color: #1f2937;
      font-size: 32px;
    }

    p {
      font-size: 18px;
      color: #374151;
      margin: 18px 0 10px;
    }

    button {
      padding: 10px 18px;
      margin: 4px;
      border: none;
      border-radius: 8px;
      font-size: 16px;
      cursor: pointer;
      font-weight: 600;
      transition: 0.2s ease;
    }

    button[onclick*="on"] {
      background: #10b981;
      color: white;
    }
    button[onclick*="on"]:hover {
      background: #0a8f62;
    }

    button[onclick*="off"] {
      background: #ef4444;
      color: white;
    }
    button[onclick*="off"]:hover {
      background: #c73232;
    }

    button[onclick*="autoMode('on')"] {
      background: #3b82f6;
      color: white;
    }
    button[onclick*="autoMode('on')"]:hover {
      background: #2563eb;
    }

    button[onclick*="autoMode('off')"] {
      background: #f59e0b;
      color: white;
    }
    button[onclick*="autoMode('off')"]:hover {
      background: #d97706;
    }

    #led, #auto, #ldr {
      font-weight: bold;
      color: #111827;
      padding: 3px 6px;
      background: #e5e7eb;
      border-radius: 4px;
    }
  </style>
</head>

<body>
  <h1>Pi LED + LDR</h1>

  <p>LED: <span id="led">...</span></p>
  <button onclick="led('on')">ON</button>
  <button onclick="led('off')">OFF</button>

  <p>Auto Mode: <span id="auto">...</span></p>
  <button onclick="autoMode('on')">Enable</button>
  <button onclick="autoMode('off')">Disable</button>

  <p>LDR D0: <span id="ldr">...</span> (1 = DARK)</p>

  <script src="/static/control/control.js"></script>
</body>
</html>

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

15) Create static JS

Using your preferred editor, create control/static/control/control.js and edit

mkdir -p control/static/control

nano control/static/control/control.js

async function state(){
  let r = await fetch('/api/state/');
  let s = await r.json();
  document.getElementById('led').innerText = s.led_on ? "ON" : "OFF";
  document.getElementById('auto').innerText = s.auto ? "ON" : "OFF";
  document.getElementById('ldr').innerText = s.ldr_d0;
}

async function led(a){ await fetch('/api/led/?action='+a); state(); }
async function autoMode(a){ await fetch('/api/auto/?mode='+a); state(); }

setInterval(state, 500);
state();

Press ctrl+o to save
Then press Enter
Then press ctrl+x to exit

16) pip install RPI

pip install RPI.gpio

17) Migrate DB

python manage.py migrate

18) Run Django

python manage.py runserver 0.0.0.0:8000

Server Running! Open your browser and visit:

http://<your-pi-ip>:8000/

Note: The example above uses python3-rpi.gpio and accesses GPIO directly. Run the Django server under a user with permission to access the GPIO pins (usually the default "pi" user). On some systems you may prefer to run the gpio poller as a system service.

Raspberry pi 4B - Pin Connections

1) Pin Connections

2) LDR and LED Connection

Connect LDR module digital output (D0) to GPIO27, VCC to 3.3V, and GND to ground.
Connect LED long leg (positive) to GPIO17 and short leg (negative) to GND.

Gallery

Program Overview

Part 1: Raspberry Pi — Imager & VNC Setup

Download Raspberry Pi Imager

Step-by-step: Flash OS using Raspberry Pi Imager

VNC: Remote Desktop Access (RealVNC)

Download RealVNC Viewer

Install RealVNC Viewer

Create New VNC Connection

SSH Access to Raspberry Pi

Connect via SSH from Windows Command Prompt

Using raspi-config Tool

Open the saved VNC profile and connect

Open the terminal

Update the system packages

Part 2: LED Blynk Project

1) Open the Terminal

2) Create project

3) LED Blynk Code

Raspberry Pi 4B - Connections

1) Pin Connections

2) LED Connection

4) Run the code

Part 3: LDR Sensor

1) Open the Terminal

2) Create project

3) LDR code

Raspberry pi 4B - Pin Connections

1) Pin Connections

2) LDR and LED Connection

4) Run the code

Part 4: Automation (Django)

1) Open the Terminal

2) Create project folder

3) Creating Virtual Environment

4) Install Django

5) Updating pip

6) Install Raspberry Pi GPIO Libraries

7) Create Django project

8) Create Django app

9) Update pi_web/settings.py

10) Configure URLs

11) Create control/urls.py

12) Create GPIO hardware file

13) Create views

14) Create templates

15) Create static JS

16) pip install RPI

17) Migrate DB

18) Run Django

Raspberry pi 4B - Pin Connections

1) Pin Connections

2) LDR and LED Connection

Run the code

After doing the Connections, run your server and have fun with automation with Django!

A special thanks to

Coordinators, Audience, and Everyone Who Helped Make This Session Possible

9) Update `pi_web/settings.py`

11) Create `control/urls.py`