VintageNet WiFi Configuration Wizard

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This is a WiFi configuration wizard that uses VintageNet. It is intended for use in Nerves-based devices that don't have a display for configuring WiFi.

Here's the intended use:

  1. On device initialization, if WiFi hasn't been configured, configure WiFi to AP mode and start a webserver
  2. A user connects to the access point and opens a web browser. The only website they can go to in the configuration utility.
  3. The configuration utility shows a list of access points and the user can select one or more or enter information for a hidden access point
  4. The user applies the configuration and the device stops AP mode and connects to the access point.

VintageNet persists WiFi configuration so the device will be able to connect after reboots and power outages. To change the configuration later, a user needs to take a device-specific action like hold down a button for 5 seconds. This library has an example project for the Raspberry Pi for use as a demo.

see it in action

Features

  • [x] - Simple web-based configuration utility
  • [x] - WiFi scanning while in AP mode
  • [x] - JSON REST-based API to support smartphone app-based configuration
  • [ ] - Captive portal - the webserver is at a static IP address, but it currently won't trigger captive portal detection
  • [x] - WPA PSK configuration
  • [ ] - WPA EAP configuration
  • [x] - Hidden AP configuration
  • [x] - Multiple AP selection (device tries access points in order until one works)
  • [ ] - Custom styling and branding

Supported WiFi adapters

Not all WiFi adapters support AP mode use or their device drivers require patching when used on Linux. Here are the ones that we've used:

  1. Raspberry Pi Zero W and Raspberry Pi 3 WiFi modules
  2. RT5370-based USB modules

It is highly likely that other modules work. We have not had any luck with Realtek RTL8192c (in the popular Edimax EW7811Un) or MediaTek MT7601u (in lots of brands).

Configuration

It is expected that you're using VintageNet already. If you're not, see that project first.

VintageNetWizard is an OTP application so it's mostly self-contained. Add it to your mix dependencies like so:

   {:vintage_net_wizard, "~> 0.1"}

The configuration wizard is not started by default to allow for more control over business specific situations. You will need to add a call in your code when you want the device placed into AP mode and the wizard started:

defmodule MyApp do
  use Application

  def start(_type, _args) do
    if should_start_wizard?() do
      VintageNetWizard.run_wizard
    end
    # ...
    Supervisor.start_link(children, opts)
  end
end

This will be sufficient to try it out on a device that hasn't been configured yet. You will want to add a mechanism for forcing the wizard the run WiFi configuration again, such as holding a button for 5+ seconds. Take a look at Running the example section for steps on setting up a button and running a quick example firmware on a device.

DNS in AP-mode

When the wizard is running, users go to either http://192.168.0.1/ or http://wifi.config/ to access the web user interface. The latter can be changed via the config.exs:

config :vintage_net_wizard,
  dns_name: "my-wifi-config.com"

Port

VintageNetWizard starts a webserver on port 80 by default. If port 80 is not available on your device or you would prefer a different port, add the following to your config.exs:

config :vintage_net_wizard,
  port: 4001

If SSL is enabled the default port is 443.

SSL

To use SSL with the web UI, you can pass SSL options to VintageNetWizard.run_wizard/1:

VintageNetWizard.run_wizard(ssl: [keyfile: "/path/to/key.pem", certfile: "/path/to/cert.pem"])

To see all available options see Plug.SSL.configure/1 and Erlang's :ssl module.

Backends

Backends control how VintageNetWizard configures the network. The default backend changes the network configuration as you would expect. This can get in the way of development and can be disabled by using the VintageNetWizard.Backend.Mock backend:

config :vintage_net_wizard,
  backend: VintageNetWizard.Backend.Mock

The default backend also times out a configuration attempt if it is unable to connect to any of the specified networks within 15 sec (this might occur if the password is incorrect or otherwise faulty network). You can adjust this timeout in the config for more control of how long you want to allow the device to attempt the new configuration:

config :vintage_net_wizard, configuration_timeout: 30_000

JSON API

It is possible to write a smartphone app to configure your device using an API endpoint. Documentation for the API is in json-api.md.

Running the example

The example builds a Nerves firmware image for supported Nerves devices that demonstrates the wizard. The wizard will run on the first boot and also after a button has been held down for 5 seconds.

For the button to work, you'll need to wire up a button to GPIO 17/pin 11 and 3v3/pin 1 on the Raspberry Pi's GPIO header. See the image below for the location:

Raspberry Pi Pinout from pinout.xyz

If you don't have a button, you can use a jumper wire to temporarily connect 3v3 power to pin 11. If you have a Raspberry Pi hat with a button connected to a different GPIO pin, you can specify with pin to use in your config:

config :vintage_net_wizard, gpio_pin: 27

The next step is to build the firmware. Make sure that you've installed Nerves and run the following:

cd example

# Set the target to rpi0, rpi3, or rpi4 depending on what you have
export MIX_TARGET=rpi3
mix deps.get
mix firmware

# Insert a MicroSD card or whatever media your board takes
mix burn

Place the MicroSD card in the Raspberry Pi and power it on. You should see a WiFi access point appear with the SSID "nerves-1234" where "1234" are part of the device's serial number. Connect to the access point and then point your web browser at http://wifi.config or http://192.168.0.1/. If you've configured an SSL certificate, it's possible to use https. You may also need to change the :dns_name configuration to match the name on your SSL certificate.