Controlling Arduino via REST API

The ardulink-rest module exposes your Arduino as a REST API, letting you control pins and read values using HTTP/JSON. It includes a built-in Swagger UI so you can interact with your Arduino directly from a browser.

What It Does

ardulink-rest is a standalone server that:

  1. Connects to your Arduino via any Ardulink link
  2. Exposes REST endpoints for pin control
  3. Serves a Swagger UI for interactive exploration
  4. Supports full CRUD operations on digital and analog pins
┌──────────┐  Serial   ┌──────────────┐  REST/HTTP  ┌──────────────┐
│  Arduino │ <───────> │ ardulink-rest│ <─────────> │   Browser /  │
│  (FW)    │           │ (server)     │             │   curl / API │
└──────────┘           └──────────────┘             └──────────────┘

Quick Start

1. Start the REST Server 

java -jar ardulink-rest-2.3.1.jar \
    -connection "ardulink://serial?port=/dev/ttyACM0"

For testing:

java -jar ardulink-rest-2.3.1.jar \
    -connection "ardulink://virtual-console"

2. Open Swagger UI

Navigate to http://localhost:8080 in your browser. You’ll see the Swagger UI with all available endpoints.

3. Control Arduino from the Browser

Use the interactive Swagger UI to:

  • List available pins
  • Read digital/analog pin values
  • Switch digital pins on/off
  • Set analog pin values
  • Send custom messages

REST API Endpoints

Method Endpoint Description
GET /api/pins List all available pins
GET /api/digital/{pin} Read digital pin value
PUT /api/digital/{pin} Set digital pin value
GET /api/analog/{pin} Read analog pin value
PUT /api/analog/{pin} Set analog pin value
POST /api/custom Send custom message

Using with curl

Set Digital Pin HIGH 

curl -X PUT http://localhost:8080/api/digital/13 \
    -H "Content-Type: application/json" \
    -d '{"value": true}'

Read Analog Pin 

curl http://localhost:8080/api/analog/0

Set Analog Pin Value 

curl -X PUT http://localhost:8080/api/analog/0 \
    -H "Content-Type: application/json" \
    -d '{"value": 512}'

Maven Dependency

For programmatic REST server setup:

<dependency>
    <groupId>org.ardulink</groupId>
    <artifactId>ardulink-rest</artifactId>
    <version>2.3.1</version>
</dependency>

Use Cases

  • Web dashboards — Build HTML/JS dashboards that control Arduino
  • Mobile apps — REST APIs work from any HTTP client
  • Testing — Quick pin testing from the browser
  • Integration — Connect Arduino to any REST-compatible system
  • Microservices — Arduino as a REST endpoint in a larger architecture

Next Steps