Serving sensor data as JSON API in Raspberry Pi - Mini Project: Build & Apply

Serving sensor data as JSON API

📖 Scenario: You have a Raspberry Pi connected to a temperature sensor. You want to share the sensor readings over a simple web API that returns the data in JSON format. This way, other devices or apps can easily get the current temperature.

🎯 Goal: Build a small Python program that reads temperature data from a sensor (simulated), sets up a web server, and serves the sensor data as a JSON response when accessed.

📋 What You'll Learn

Create a dictionary with sensor data including 'temperature' and 'unit'.

Create a variable called 'port' to set the server port number.

Use Flask to create a web server with a route '/' that returns the sensor data as JSON.

Print a message showing the server is running on the specified port.

💡 Why This Matters

🌍 Real World

Sharing sensor data as JSON over a network is common in IoT projects, home automation, and remote monitoring.

💼 Career

Understanding how to serve JSON APIs is important for backend development, embedded systems, and working with connected devices.

1

Create sensor data dictionary

Create a dictionary called sensor_data with these exact entries: 'temperature': 23.5 and '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 'temperature' and 'unit'.

2

Set server port variable

Create a variable called port and set it to 5000.

Raspberry Pi

sensor_data = {'temperature': 23.5, 'unit': 'Celsius'}
# Create a variable port and set it to 5000
# Your code here

Need a hint?

Just assign the number 5000 to the variable named port.

3

Create Flask app and route

Import Flask and jsonify from flask. Create a Flask app called app. Define a route for '/' that returns jsonify(sensor_data).

Raspberry Pi

sensor_data = {'temperature': 23.5, 'unit': 'Celsius'}
port = 5000
# Import Flask and jsonify
# Create app = Flask(__name__)
# Define route '/' that returns jsonify(sensor_data)
# Your code here

Need a hint?

Use @app.route('/') to create the route and return the sensor_data as JSON.

4

Run the Flask server and print message

Add the code to run the Flask app with app.run(host='0.0.0.0', port=port). Before running, print f"Server running on port {port}".

Raspberry Pi

from flask import Flask, jsonify

sensor_data = {'temperature': 23.5, 'unit': 'Celsius'}
port = 5000

app = Flask(__name__)

@app.route('/')
def get_sensor_data():
    return jsonify(sensor_data)

# Print server running message and run app
# Your code here

Need a hint?

Use print(f"Server running on port {port}") and then app.run(host='0.0.0.0', port=port).