REST API for IoT device in Raspberry Pi - Mini Project: Build & Apply

REST API for IoT Device

📖 Scenario: You have a Raspberry Pi connected to a temperature sensor. You want to create a simple REST API so other devices or apps can get the current temperature reading.This project will guide you step-by-step to build a basic REST API using Python and Flask on your Raspberry Pi.

🎯 Goal: Build a REST API on your Raspberry Pi that returns the current temperature reading as JSON when accessed.

📋 What You'll Learn

Create a Python dictionary to simulate sensor data

Add a configuration variable for the API endpoint path

Use Flask to create a REST API endpoint that returns the sensor data

Print the API URL to the console

💡 Why This Matters

🌍 Real World

IoT devices often need to share sensor data with other devices or apps. A REST API is a common way to do this over a network.

💼 Career

Understanding how to build REST APIs on devices like Raspberry Pi is useful for IoT developers, embedded systems engineers, and backend programmers working with connected devices.

1

Create sensor data dictionary

Create a Python dictionary called sensor_data with these exact entries: 'temperature': 22.5, 'unit': 'Celsius'.

Raspberry Pi

# Create the sensor_data dictionary with temperature and unit
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys and values.

2

Add API endpoint path configuration

Create a variable called api_path and set it to the string "/temperature".

Raspberry Pi

sensor_data = {'temperature': 22.5, 'unit': 'Celsius'}
# Create the api_path variable with the value '/temperature'
# Your code here

Need a hint?

Assign the string "/temperature" to the variable api_path.

3

Create Flask REST API endpoint

Import Flask and jsonify from flask. Create a Flask app called app. Use @app.route(api_path) to define a function get_temperature() that returns jsonify(sensor_data).

Raspberry Pi

sensor_data = {'temperature': 22.5, 'unit': 'Celsius'}
api_path = "/temperature"
# Import Flask and jsonify, create app, and define route
# Your code here

Need a hint?

Use @app.route(api_path) to create the API endpoint and return the sensor data as JSON.

4

Run the Flask app and print API URL

Add the code to run the Flask app with app.run(host='0.0.0.0', port=5000) inside if __name__ == '__main__':. Before running, print the string "API running at http://localhost:5000".

Raspberry Pi

from flask import Flask, jsonify

sensor_data = {'temperature': 22.5, 'unit': 'Celsius'}
api_path = "/temperature"

app = Flask(__name__)

@app.route(api_path)
def get_temperature():
    return jsonify(sensor_data)

# Print API URL and run the Flask app
# Your code here

Need a hint?

Use if __name__ == '__main__': to run the app and print the API URL before starting.