Home automation with relay modules in Raspberry Pi - Mini Project: Build & Apply

Home automation with relay modules

📖 Scenario: You have a Raspberry Pi connected to 3 relay modules. Each relay controls a different home appliance: a lamp, a fan, and a heater. You want to write a simple program to turn these appliances on or off based on a list of commands.

🎯 Goal: Build a Python program that stores the relay pins and appliance names, sets a command to turn appliances on or off, applies the commands using a loop, and prints the final states of each appliance.

📋 What You'll Learn

Create a dictionary with relay pins as keys and appliance names as values

Create a dictionary with appliance names as keys and their desired states ('ON' or 'OFF') as values

Use a for loop to iterate over the relay pins and appliances

Print the appliance name and its final state

💡 Why This Matters

🌍 Real World

Home automation systems use relay modules to control appliances like lights, fans, and heaters remotely or automatically.

💼 Career

Understanding how to control hardware with code is important for jobs in IoT, embedded systems, and home automation engineering.

1

Set up relay pins and appliances

Create a dictionary called relays with these exact entries: 17: 'Lamp', 27: 'Fan', 22: 'Heater'.

Raspberry Pi

# Create the relays dictionary with pin numbers and appliance names
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys as pin numbers and values as appliance names.

2

Set appliance commands

Create a dictionary called commands with these exact entries: 'Lamp': 'ON', 'Fan': 'OFF', 'Heater': 'ON'.

Raspberry Pi

relays = {17: 'Lamp', 27: 'Fan', 22: 'Heater'}
# Create the commands dictionary with appliance names and their states
# Your code here

Need a hint?

Use a dictionary to map appliance names to their desired states.

3

Apply commands to relays

Use a for loop with variables pin and appliance to iterate over relays.items(). Inside the loop, create a variable state that gets the command for the appliance from commands.

Raspberry Pi

relays = {17: 'Lamp', 27: 'Fan', 22: 'Heater'}
commands = {'Lamp': 'ON', 'Fan': 'OFF', 'Heater': 'ON'}
# Use a for loop to get pin and appliance, then get the state from commands
# Your code here

Need a hint?

Use relays.items() to get both pin and appliance in the loop.

4

Print appliance states

Inside the for loop, add a print statement that shows the appliance name and its state in this exact format: "Lamp is ON".

Raspberry Pi

relays = {17: 'Lamp', 27: 'Fan', 22: 'Heater'}
commands = {'Lamp': 'ON', 'Fan': 'OFF', 'Heater': 'ON'}
for pin, appliance in relays.items():
    state = commands[appliance]
    # Print the appliance and its state
    # Your code here

Need a hint?

Use an f-string to print the appliance and its state exactly as shown.