Sensor Readouts

A Flask web application for managing and visualizing sensor data. It provides a REST API for creating sensors and storing readouts, along with a frontend dashboard that displays real-time charts and tabular data.

Tech Stack

Python 3.13+
Flask 3 — web framework
SQLAlchemy (via Flask-SQLAlchemy) — ORM
SQLite — database
Alembic — database migrations
Chart.js — frontend charting library

Project Structure

server/
├── app.py              # Flask application factory and API routes
├── models.py           # SQLAlchemy models (Sensor, SensorReadout)
├── seed.py             # Database seeder with sample data
├── requirements.txt    # Python dependencies
├── data.db             # SQLite database (auto-created)
├── alembic.ini         # Alembic configuration
├── alembic/            # Migration scripts
│   ├── env.py
│   └── versions/
└── templates/
    ├── sensors.html    # Dashboard with chart and table
    └── docs.html       # API documentation page

Setup

# Create and activate virtual environment
python3 -m venv .venv
source .venv/bin/activate

# Install dependencies
pip install -r requirements.txt

# Run database migrations
alembic upgrade head

# (Optional) Seed the database with sample data
python seed.py

Running

python app.py

The server starts on http://localhost:5000.

Route	Description
`/sensors`	Dashboard with interactive chart and data table
`/api/docs`	API documentation with curl examples

Database

Two tables are used:

sensor

Column	Type	Description
`id`	Integer	Primary key
`name`	String(128)	Unique sensor name
`created_at`	DateTime	Creation timestamp (UTC)

sensor_readout

Column	Type	Description
`id`	Integer	Primary key
`sensor_id`	Integer	Foreign key to `sensor.id`
`type`	String(64)	Readout type (e.g. `temperature`, `pressure`, `humidity`)
`value`	Float	Measured value
`timestamp`	DateTime	Readout timestamp (UTC)

Migrations

# Create a new migration after model changes
alembic revision --autogenerate -m "description"

# Apply pending migrations
alembic upgrade head

# Roll back one step
alembic downgrade -1

API

Base URL: http://localhost:5000/api

Endpoints

Method	Path	Description
`GET`	`/api/sensors`	List all sensors
`POST`	`/api/sensors`	Create a new sensor
`GET`	`/api/sensors/:id/types`	List readout types for a sensor
`GET`	`/api/sensors/:id/readouts`	Latest readouts (max 300, filterable by `?type=`)
`GET`	`/api/sensors/:id/readouts/hourly`	Hourly averaged readouts (filterable by `?type=`)
`POST`	`/api/sensors/:id/readouts`	Add a new readout

Examples

# List sensors
curl http://localhost:5000/api/sensors

# Create a sensor
curl -X POST http://localhost:5000/api/sensors \
     -H "Content-Type: application/json" \
     -d '{"name": "bmp280"}'

# Get temperature readouts for sensor 1
curl "http://localhost:5000/api/sensors/1/readouts?type=temperature"

# Get hourly averaged data
curl "http://localhost:5000/api/sensors/1/readouts/hourly?type=temperature"

# Add a readout
curl -X POST http://localhost:5000/api/sensors/1/readouts \
     -H "Content-Type: application/json" \
     -d '{"type": "temperature", "value": 22.5}'

Full API documentation with request/response examples is available at /api/docs.

Frontend

The dashboard at /sensors provides:

Sensor dropdown — select a sensor from the list
Type dropdown — select a readout type (populated based on the chosen sensor)
Line chart — hourly averaged values rendered with Chart.js
Data table — raw readouts with formatted timestamps (latest 300 entries)

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