# Arduino Router Bridge

Originally developed for the Arduino Uno Q, this library is an Elixir interface 
for communicating with the
[Arduino Router](https://github.com/arduino/arduino-router)

The library communicates via the router's Unix socket. It exposes a 
GenServer-based `ArduinoRouter.Bridge` module that enables callers to make 
RPC calls (and notifications). It also allows Elixir code to register RPC
methods and respond to them from Elixir.

The actual transport mechanism used by the bridge is pluggable 
(primarily to faciliate unit testing in the library).  The 
`ArduinoRouter.Socket` module conforms to the transport behaviour and handles
some details of working with the android-router's Unix socket.

## Features

- Synchronous (`call/2`) and asynchronous (`call_async/2`) RPC calls
- Notifications (`notify/2`) for fire-and-forget messages
- Register local handlers for incoming RPC requests (`provide/3`)

## Usage

Start the bridge:

```elixir
{:ok, _pid} = ArduinoRouter.Bridge.start_link()
```

Use a custom transport (used for tests or perhaps alternative transports):

```elixir
{:ok, _pid} = ArduinoRouter.Bridge.start_link(transport: {MyTransport, [opt: value]})
```

Register a handler for incoming RPC requests:

```elixir
ArduinoRouter.Bridge.provide("get_current_weather", WeatherProvider, :get_current_forecast)
```

Synchronous call (blocks until a response or timeout):

```elixir
ArduinoRouter.Bridge.call("get_sensor_reading", [])
# => {:ok, result} | {:error, reason}
```

Asynchronous call. Returns `:ok` immediately and sends a message to the process
that called `call_async` when a response is received:

```elixir
ArduinoRouter.Bridge.call_async("long_running", [1, 2])
```

Send a notification (fire-and-forget):

```elixir
ArduinoRouter.Bridge.notify("log_message", ["Hello from Elixir"])
```

> [!TIP]
> If you alias the `ArduinoRouter.Bridge` module then
> `ArduinoRouter.Bridge.call>(...)` becomes `Bridge.call(...)` which makes
> the code look very similar to the same code in a Sketch, or through the
> Python interface.

## License

This project is licensed under the MIT License — see the `LICENSE` file for
details. SPDX identifier: `MIT`.

## Contributing

Bug reports and pull requests are welcome. Fixes will be made as time permists

## Authors

This project was created by Scott Thompson