Nerves.InterimWiFi

Connect to WiFi networks on Nerves platforms.

Installation

1. Add nerves_interim_wifi to your list of dependencies in mix.exs:

   def deps do
     [{:nerves_interim_wifi, "~> 0.2.0"}]
   end

2. Ensure nerves_interim_wifi is started before your application:

def application do
  [applications: [:nerves_interim_wifi]]
end

3. Set the regulatory domain in your config.exs. This should be set to the ISO 3166-1 alpha-2 country code where the device is running. If your device ships to more than one country, see Nerves.InterimWiFi.set_regulatory_domain\1.
   • if unset, the default regulatory domain is the world domain, "00"

   config :nerves_interim_wifi,
     regulatory_domain: "US"

Setup

Before WiFi will work, you will need to load any modules for your device if they aren't loaded already. Here's an example for Raspberry Pi 0 and Rasbperry Pi 3

{_, 0} = System.cmd("modprobe", ["brcmfmac"])

Scanning

You can scan by running:

iex> {:ok, _pid} = Nerves.InterimWiFi.setup "wlan0"
iex> Nerves.InterimWiFi.scan "wlan0"
[%{age: 42, beacon_int: 100, bssid: "00:1f:90:db:45:54", capabilities: 1073,
   flags: "[WEP][ESS]", freq: 2462, id: 8,
   ie: "00053153555434010882848b0c1296182403010b07",
   level: -83, noise: 0, qual: 0, ssid: "1SUT4", tsf: 580579066269},
 %{age: 109, beacon_int: 100, bssid: "00:18:39:7a:23:e8", capabilities: 1041,
   flags: "[WEP][ESS]", freq: 2412, id: 5,
   ie: "00076c696e6b737973010882848b962430486c0301",
   level: -86, noise: 0, qual: 0, ssid: "linksys", tsf: 464957892243},
 %{age: 42, beacon_int: 100, bssid: "1c:7e:e5:32:d1:f8", capabilities: 1041,
   flags: "[WPA2-PSK-CCMP][ESS]", freq: 2412, id: 0,
   ie: "000768756e6c657468010882848b960c1218240301",
   level: -43, noise: 0, qual: 0, ssid: "dlink", tsf: 580587711245}]

Running

Setup your WiFi connection by running:

Nerves.InterimWiFi.setup "wlan0", ssid: "my_accesspoint_name", key_mgmt: :"WPA-PSK", psk: "secret"

If your WiFi network does not use a secret key, specify the key_mgmt to be :NONE. Currently, wireless configuration passes almost unaltered to wpa_supplicant.ex, so see that project for more configuration options.

Limitations

Currently, only IPv4 is supported, and IP addresses can only be assigned via DHCP. The library is incredibly verbose in its logging to help debug issues on new platforms in prep for a first release. This will change. The library is mostly interim in its structure. Please consider submitting PRs and helping make this work reliably across embedded devices.