User Interfaces
Phoenix Web Interfaces
Phoenix makes an excellent companion to Nerves applications by offering an easy-to-use, powerful framework to create user interfaces in parallel with Nerves device code. The easiest way to handle this is to lay out your application as an Umbrella.
First, generate a new umbrella app, called nervy
in this case:
$ mix new nervy --umbrella
Next, create your sub-applications for Nerves and for Phoenix:
$ cd nervy/apps
$ mix nerves.new fw
$ mix phoenix.new ui --no-ecto --no-brunch
Now, add the Phoenix ui
app and the nerves_networking
library to the fw
app as dependencies:
# nervy/apps/fw/mix.exs
...
defp deps do
[{:ui, in_umbrella: true},
{:nerves_networking, "~> 0.6.0"}]
end
...
In order to start networking when fw
boots, add a worker that sets up networking.
This example sets up the networking using DHCP.
For more network settings, check the nerves_networking
project.
# nervy/apps/fw/lib/fw.ex
...
# add networking
children = [
worker(Task, [fn -> Nerves.Networking.setup :eth0, [mode: "dhcp"] end], restart: :transient)
]
...
In order to build the ui
Phoenix application into the nerves fw
app, you need to add some configuration to your firmware config:
# nervy/apps/fw/config/config.exs
use Mix.Config
config :ui, Ui.Endpoint,
http: [port: 80],
url: [host: "localhost", port: 80],
secret_key_base: "#############################",
root: Path.dirname(__DIR__),
server: true,
render_errors: [accepts: ~w(html json)],
pubsub: [name: Nerves.PubSub]
config :logger, level: :debug
There you have it! A Phoenix web application ready to run on your Nerves device. By separating the Phoenix application from the Nerves application, you could easily distribute the development between team members and continue to leverage the features we have all come to love from Phoenix, like live code reloading.
When developing your UI, you can simply run the phoenix server from the UI application:
$ cd nervy/apps/ui
$ mix phoenix.server
When it’s time to create your firmware:
$ cd nervy/apps/fw
$ export MIX_TARGET=rpi3
$ mix deps.get
$ mix firmware
$ mix firmware.burn