![MIX FILE
defmodule MyApp.Mixfile do
…
def project do
[app: :my_app,
version: "0.1.0",
archives: [nerves_bootstrap: "~> 0.1"],
target: @target,
deps_path: "deps/#{@target}",
build_path: "_build/#{@target}",
aliases: aliases,
deps: deps ++ system(@target)]
end
end
New Projects](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-27-320.jpg){kind=icon}
![MIX FILE
defmodule MyApp.Mixfile do
…
def aliases do
["deps.precompile": ["nerves.precompile", "deps.precompile"],
"deps.loadpaths": ["deps.loadpaths", "nerves.loadpaths"]]
end
end
New Projects](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-28-320.jpg){kind=icon}
![MIX FILE
defmodule MyApp.Mixfile do
…
def system(target) do
[{:"nerves_system_#{target}", ">= 0.0.0"}]
end
…
end
New Projects](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-29-320.jpg){kind=icon}
![TARGET SPECIFIC CONFIG
# config.exs
use Mix.Config
import_config "#{Mix.Project.config[:target]}.exs"
Multi-Target](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-45-320.jpg){kind=icon}
![MIX FILE
defmodule BlinkyAle.Mixfile do
…
def application do
[mod: {BlinkyAle, []},
applications: [:logger, :elixir_ale]]
end
def deps do
[{:nerves, "~> 0.3.0"},
{:elixir_ale, "~> 0.5.6"}]
end
end
Blinky Elixir Ale](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-87-320.jpg){kind=icon}
![defmodule BlinkyAle do
use Application
# See http://elixir-lang.org/docs/stable/elixir/Application.html
# for more information on OTP Applications
def start(_type, _args) do
import Supervisor.Spec, warn: false
# Define workers and child supervisors to be supervised
children = [
worker(Task, [fn -> blink end], restart: :transient),
]
# See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
# for other strategies and supported options
opts = [strategy: :one_for_one, name: BlinkyAle.Supervisor]
Supervisor.start_link(children, opts)
end
...
end
Blinky Elixir Ale](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-88-320.jpg){kind=icon}
![Running on the Host
defmodule BlinkyFirmataHost.Mixfile do
...
def application do
[applications: [:logger, :firmata],
mod: {BlinkyFirmataHost, []}]
end
defp deps do
[{:firmata, github: "mobileoverlord/firmata"}]
end
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-97-320.jpg){kind=icon}
![Running on the Host
defmodule BlinkyFirmataHost.Protocol do
use GenServer
use Firmata.Protocol.Mixin
alias Firmata.Board
def start_link(tty, opts []) do
GenServer.start_link(__MODULE__, [tty, opts], name: __MODULE__)
end
def init([tty, opts]) do
IO.puts "Init"
{:ok, board} = Board.start_link(tty, opts)
{:ok, %{
board: board
}}
end
...
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-98-320.jpg){kind=icon}
![Running on the Target
defmodule BlinkyFirmata.Mixfile do
...
def application do
[applications: [:logger, :firmata],
mod: {BlinkyFirmata, []}]
end
defp deps do
[{:nerves, "~> 0.3.0"},
{:firmata, github: "mobileoverlord/firmata"}]
end
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-106-320.jpg){kind=icon}
![Running on the Target
defmodule BlinkyFirmata.Protocol do
use GenServer
use Firmata.Protocol.Mixin
alias Firmata.Board
def start_link(tty, opts []) do
GenServer.start_link(__MODULE__, [tty, opts], name: __MODULE__)
end
def init([tty, opts]) do
IO.puts "Init"
{:ok, board} = Board.start_link(tty, opts)
{:ok, %{
board: board
}}
end
...
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-107-320.jpg){kind=icon}
![Running on the Target
defmodule BlinkyFirmata do
use Application
def start(_type, _args) do
import Supervisor.Spec, warn: false
# Define workers and child supervisors to be supervised
children = [
worker(BlinkyFirmata.Protocol, ["ttyS0"]),
]
# See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
# for other strategies and supported options
opts = [strategy: :one_for_one, name: BlinkyFirmata.Supervisor]
Supervisor.start_link(children, opts)
end
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-109-320.jpg){kind=icon}
![Project Layout
# apps/badge_fw/mix.exs
def application do
[mod: {BadgeFw, []},
applications: [:logger, :badge_lib]]
end
def deps do
[{:nerves, "~> 0.3.0"},
{:badge_lib, in_umbrella: true}]
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-120-320.jpg){kind=icon}
![Initialization
# apps/badge_fw/mix.exs
def application do
[mod: {BadgeFw, []},
applications: [:logger, :badge_lib, :nerves_interim_wifi]]
end
def deps do
[{:nerves, "~> 0.3.0"},
{:nerves_interim_wifi, "~> 0.1"},
{:badge_lib, in_umbrella: true}]
end
# apps/badge_fw
$ mix deps.get](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-125-320.jpg){kind=icon}
![Initialization
# apps/badge_fw/lib/badge_fw.ex
defmodule BadgeFw do
use Application
alias Nerves.InterimWiFi, as: WiFi
def start(_type, _args) do
import Supervisor.Spec, warn: false
:os.cmd('modprobe mt7603e')
# Define workers and child supervisors to be supervised
children = [
worker(Task, [fn -> network end], restart: :transient),
]
# See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
# for other strategies and supported options
opts = [strategy: :one_for_one, name: BadgeFw.Supervisor]
Supervisor.start_link(children, opts)
end
def network do
wlan_config = Application.get_env(:badge_fw, :wlan0)
WiFi.setup "wlan0", wlan_config
end
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-126-320.jpg){kind=icon}
![Initialization
# apps/badge_fw/mix.exs
def application do
[mod: {BadgeFw, []},
applications: [:logger, :badge_lib, :nerves_interim_wifi,
:nerves_ntp]]
end
def deps do
[{:nerves, "~> 0.3.0"},
{:nerves_interim_wifi, "~> 0.1"},
{:nerves_ntp, "~> 0.1"},
{:badge_lib, in_umbrella: true}]
end
# apps/badge_fw
$ mix deps.get](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-129-320.jpg){kind=icon}
![# apps/badge_fw/config/config.exs
config :nerves_ntp, :ntpd, "/usr/sbin/ntpd"
config :nerves_ntp, :servers, [
"0.pool.ntp.org",
"1.pool.ntp.org",
"2.pool.ntp.org",
"3.pool.ntp.org"
]
Initialization](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-130-320.jpg){kind=icon}
![# badge_lib/mix.exs
def application do
[applications: [:logger, :firmata]]
end
defp deps do
[{:firmata, github: "mobileoverlord/firmata"}]
end
Arduino Firmata
$ mix deps.get](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-136-320.jpg){kind=icon}
![Arduino Firmata
defmodule BadgeLib.Firmata do
use GenServer
use Firmata.Protocol.Modes
alias Firmata.Board, as: Board
def start_link(opts []) do
port = opts[:port] || "ttyS0"
speed = opts[:speed] || 57600
serial_opts = [speed: speed]
GenServer.start_link(__MODULE__, [port, serial_opts], name: __MODULE__)
end
def init([port, serial_opts]) do
{:ok, board} = Board.start_link(port, serial_opts)
{:ok, %{
board: board
}}
end
...
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-139-320.jpg){kind=icon}
![Arduino Firmata
defmodule BadgeLib.Firmata do
use GenServer
use Firmata.Protocol.Modes
alias Firmata.Board, as: Board
@high 1
@low 0
@vibration_pin 9
def start_link(opts [])
def vibrate(state @high) do
GenServer.call(__MODULE__, {:vibrate, state})
end
...
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-141-320.jpg){kind=icon}
![Arduino Firmata
defmodule BadgeFw do
use Application
alias Nerves.InterimWiFi, as: WiFi
def start(_type, _args) do
import Supervisor.Spec, warn: false
:os.cmd('modprobe mt7603e')
# Define workers and child supervisors to be supervised
children = [
worker(Task, [fn -> network end], restart: :transient),
worker(BadgeLib.Firmata, []),
]
# See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
# for other strategies and supported options
opts = [strategy: :one_for_one, name: BadgeFw.Supervisor]
Supervisor.start_link(children, opts)
end
...
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-153-320.jpg){kind=icon}
![Connecting to Twitter
# badge_lib/mix.exs
def application do
[applications: [:logger, :firmata, :oauth, :extwitter]]
end
defp deps do
[{:firmata, github: "mobileoverlord/firmata"},
{:oauth, github: "tim/erlang-oauth"},
{:extwitter, "~> 0.6"}]
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-156-320.jpg){kind=icon}
![Connecting to Twitter
defmodule BadgeFw.Worker do
use GenServer
def start_link(opts []) do
GenServer.start_link(__MODULE__, [], opts)
end
def init([]) do
BadgeLib.Firmata.clear()
{:ok, %{}}
end
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-157-320.jpg){kind=icon}
![defmodule BadgeFw do
use Application
alias Nerves.InterimWiFi, as: WiFi
def start(_type, _args) do
import Supervisor.Spec, warn: false
:os.cmd('modprobe mt7603e')
# Define workers and child supervisors to be supervised
children = [
worker(Task, [fn -> network end], restart: :transient),
worker(BadgeLib.Firmata, []),
worker(BadgeFw.Worker, []),
]
# See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
# for other strategies and supported options
opts = [strategy: :one_for_one, name: BadgeFw.Supervisor]
Supervisor.start_link(children, opts)
end
...
end
Connecting to Twitter](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-158-320.jpg){kind=icon}
![defmodule BadgeFw.Worker do
use GenServer
@hashtag "#NervesBadge"
@handle "@ElixirConf"
@interval 25_000
def init([]) do
BadgeLib.Firmata.clear()
Process.send_after(self, :update, @interval)
{:ok, %{last: {nil, nil}}}
end
end
Connecting to Twitter](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-159-320.jpg){kind=icon}
![def get_tweet(search) do
case ExTwitter.search(search, [count: 1]) do
[tweet] -> tweet
_ -> nil
end
end
def display_tweet(tweet) do
IO.puts "display tweet"
BadgeLib.Utf8ToASCII.convert(tweet.text)
|> BadgeLib.Firmata.text
BadgeLib.Firmata.vibrate_pulse
end
Connecting to Twitter](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-161-320.jpg){kind=icon}
![# badge_fw/config/config.exs
config :extwitter, :oauth, [
consumer_key: "vnBfkubUmv10QRcQjFU3lXKin",
consumer_secret: "XUk3fsulkfraaapUyMOfnVRtd8fXdlkKMQvhjDv5nnEVrsk7yA",
access_token: System.get_env("TWITTER_ACCESS_TOKEN"),
access_token_secret: System.get_env("TWITTER_ACCESS_TOKEN_SECRET")
]
Connecting to Twitter](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-163-320.jpg){kind=icon}
![# badge_fw/mix.exs
def application do
[mod: {BadgeFw, []},
applications: [:logger, :badge_lib,
:nerves_interim_wifi, :nerves_ntp, :badge_settings]]
end
def deps do
[{:nerves, "~> 0.3.0"},
{:nerves_interim_wifi, "~> 0.1"},
{:nerves_ntp, "~> 0.1"},
{:badge_lib, in_umbrella: true},
{:badge_settings, in_umbrella: true}]
end
Web Interfaces](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-167-320.jpg){kind=icon}
![Web Interfaces
# badge_fw/config/config.exs
config :badge_settings, :nerves_settings, %{
settings_file: "/root/nerves_settings.txt",
device_name: "My Awesome Device",
application_password: System.get_env("BADGE_CONFIG_PASSWORD") ||
"nerves_rulz!"
}
config :badge_settings, BadgeSettings.Endpoint,
url: [host: "0.0.0.0"],
http: [port: 80],
secret_key_base: "R02jL0Vi+tFH7YOecTua/oc0b2dETOQT8/
Sg9dD56EDKqmd8jRAdqa0CyZ7tOFIt",
render_errors: [view: BadgeSettings.ErrorView, accepts: ~w(html json)],
server: true,
pubsub: [name: BadgeSettings.PubSub,
adapter: Phoenix.PubSub.PG2]](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-168-320.jpg){kind=icon}
![Web Interfaces
def network do
wlan_config =
case settings do
{:ok, settings} ->
[psk: settings.password, ssid: settings.ssid]
_ ->
Application.get_env(:badge_fw, :wlan0)
end
WiFi.setup "wlan0", wlan_config
end
def settings do
settings_file =
Application.get_env(:badge_settings, :nerves_settings).settings_file
case File.read(settings_file) do
{:error, :enoent} = error -> error
{:ok, ""} -> {:error, :empty}
{:ok, contents} ->
unencoded = :erlang.binary_to_term(contents)
{:ok, unencoded}
end
end](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-173-320.jpg){kind=icon}
![nerves.exs
config :nerves_system_linkit, :nerves_env,
type: :system,
version: version,
mirrors: [
"https://github.com/nerves-project/nerves_system_linkit/releases/
download/v#{version}/nerves_system_linkit-v#{version}.tar.gz",
"https://s3.amazonaws.com/nerves/artifacts/nerves_system_linkit-
#{version}.tar.gz"],
…](https://image.slidesharecdn.com/badgehacking-160915005755/85/Badge-Hacking-with-Nerves-Workshop-ElixirConf-2016-Justin-Schneck-and-Frank-Hunleth-193-320.jpg){kind=icon}
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Badge Hacking with Nerves Workshop - ElixirConf 2016 - Justin Schneck and Frank Hunleth
- 1. Nerves Project BADGE HACKING WORKSHOP
- 2. ▸ Introduction ▸ Definitions ▸ Nerves Intro ▸ Host Tools ▸ Targets ▸ Host / Target Prep What are we going to Do?
- 3. ▸ Interfacing with Hardware ▸ Boot to IEx ▸ Pin Muxing ▸ Blinky with elixir_ale ▸ Blinky with Firmata and Arduino What are we going to Do?
- 4. ▸ Building the Badge ▸ Project Layout ▸ Arduino and Firmata ▸ Connecting to Twitter ▸ Web Interfaces What are we going to Do?
- 5. ▸ Advanced Configuration ▸ Modifying a Nerves System ▸ Initialization with erlinit ▸ Firmware Updates ▸ Licensing What are we going to Do?
- 7. ▸ Introduction ▸ Definitions ▸ Nerves Intro ▸ Host Tools ▸ Targets ▸ Host / Target Prep What are we going to Do?
- 9. ▸ host ▸ target ▸ toolchain ▸ system Definitions ▸ artifact ▸ assemble ▸ firmware bundle ▸ firmware image
- 10. host The computer on which you are editing source code, compiling, and assembling firmware Definitions
- 11. target The platform for which your firmware is built (for example, Raspberry Pi, Raspberry Pi 2, or Beaglebone Black) Definitions
- 12. toolchain The tools required to build code for the target, such as compilers, linkers, binutils, and C runtime Definitions
- 13. system A lean Buildroot-based Linux distribution that has been customized and cross-compiled for a particular target Definitions
- 14. assembly The process of combining system, application, and configuration into a firmware bundle Definitions
- 15. firmware bundle A single file that contains an assembled version of everything needed to burn firmware Definitions
- 16. firmware image Built from a firmware bundle and contains the partition table, partitions, bootloader, etc. Definitions
- 17. NERVES 1.2
- 18. Nerves Your Elixir project and dependencies Linux, C libraries, Erlang runtime Nerves System Image OTP release Firmware bundle
- 19. Compiling on your machine YOUR APP ELIXIR C CODE NIF / PORTS MIX BEAM BINARY YOUR APP (ARCH SPECIFIC)
- 20. Mixing firmware MIX YOUR APP (FOR RPI2) TOOLCHAIN SYSTEM rpi2 Precompile compile
- 21. Toolchains TOOLCHAINTOOLCHAIN CONFIG • crosstool-ng • for target • host configs • compilers • run on host • compile for target
- 22. What’s in a Nerves system package? ▸ Elixir build infrastructure ▸ mix.exs – build the system image via mix ▸ nerves.exs – additional system image information such as where to find pre-built system images ▸ Buildroot configuration ▸ nerves_defconfig – top level configuration options ▸ Custom package definitions ▸ Linux kernel configuration and patches ▸ Board-specific root file system additions
- 23. Nerves Package Artifacts SYSTEM NERVES_SYSTEM_RPI3 Package TOOLCHAIN SYSTEM (TOOLCHAIN) Artifact
- 24. Create a new Nerves app
- 25. New Projects $ mix nerves.new my_app --target linkit
- 26. MIX FILE defmodule MyApp.Mixfile do use Mix.Project @target System.get_env("NERVES_TARGET") || "linkit" … end New Projects
- 27. MIX FILE defmodule MyApp.Mixfile do … def project do [app: :my_app, version: "0.1.0", archives: [nerves_bootstrap: "~> 0.1"], target: @target, deps_path: "deps/#{@target}", build_path: "_build/#{@target}", aliases: aliases, deps: deps ++ system(@target)] end end New Projects
- 28. MIX FILE defmodule MyApp.Mixfile do … def aliases do ["deps.precompile": ["nerves.precompile", "deps.precompile"], "deps.loadpaths": ["deps.loadpaths", "nerves.loadpaths"]] end end New Projects
- 29. MIX FILE defmodule MyApp.Mixfile do … def system(target) do [{:"nerves_system_#{target}", ">= 0.0.0"}] end … end New Projects
- 30. Firmware $ mix firmware $ mix firmware.burn
- 31. Flash layout Master Boot Record Bootloaders Root Filesystem A Read-only Root Filesystem B Read-only Application Data Read-write Linux kernel Erlang C libraries and apps OTP release App settings Database Logs Other files
- 32. Nerves root filesystem . ├── bin ├── dev ├── etc ├── lib ├── mnt ├── proc ├── root ├── sbin ├── srv ├── sys ├── tmp ├── usr └── var ├── srv │ └── erlang │ ├── lib │ │ ├── compiler-7.0 │ │ ├── elixir-1.3.2 │ │ ├── kernel-5.0 │ │ ├── logger-1.3.1 │ │ ├── your_app-0.1.0 │ │ ├── sasl-3.0 │ │ └── stdlib-3.0 │ └── releases │ ├── 0.0.1 │ │ ├── your_app.boot │ │ ├── your_app.rel │ │ ├── your_app.script │ │ ├── sys.config │ │ └── vm.args │ ├── RELEASES │ └── start_erl.data
- 33. HOST PREP 1.3
- 34. NERVES ▸ Erlang OTP ~> 19 ▸ Elixir ~> 1.3.2 ▸ fwup ~> 0.8.2 ▸ squashfs-tools ▸ nerves_bootstrap Host Tools ▸ Arduino IDE ~> 1.6 BADGE HACKING
- 35. Host Tools # copy and untar system and toolchain $ export NERVES_SYSTEM=/path/to/uncompressed/system $ export NERVES_TOOLCHAIN=/path/to/uncompressed/toolchain Cached Nerves System and Nerves Toolchain Since bandwidth is limited Make sure you unset after the conference.
- 37. ERLANG & ELIXIR Host Tools $ brew update $ brew install elixir Mac OS Linux https://www.erlang-solutions.com/resources/download.html http://elixir-lang.org/install.html
- 38. FWUP Host Tools $ brew install fwup Download Debian package from https://github.com/fhunleth/fwup/ $ sudo dpkg -i fwup_0.8.2_amd64.deb Mac OS Linux
- 39. ADDITIONAL TOOLS Host Tools Mac OS Linux $ brew install squashfs coreutils picocom $ sudo apt-get install squashfs-tools picocom $ sudo vigr # Add yourself to the dialout group dialout:x:20:yourusername
- 40. ADDITIONAL TOOLS Host Tools All $ mix local.hex $ mix local.rebar $ mix archive.install https://github.com/nerves-project/archives/raw/master/ nerves_bootstrap.ez
- 41. CONSOLE CABLE DRIVERS Host Tools Mac OS Linux https://www.adafruit.com/images/product-files/954/ PL2303_MacOSX_1_6_0_20151022.zip "Everything just works on Linux" ~Frank Hunleth
- 42. ARDUINO TOOLS Host Tools ▸ Install Arduino IDE ~> 1.6.0 ▸ Arduino -> Preferences -> Additional Boards Manager URLs ▸ http://download.labs.mediatek.com/ package_mtk_linkit_smart_7688_test_index.json ▸ Tools -> Board: ... -> Boards Manager ▸ Search: linkit -> install 0.1.8
- 44. Official Nerves systems ▸ nerves_system_bbb (black and green) ▸ nerves_system_rpi, nerves_system_rpi2, nerves_system_rpi3 ▸ nerves_system_qemu_arm ▸ nerves_system_alix, nerves_system_ag150 ▸ nerves_system_galileo ▸ nerves_system_linkit
- 45. TARGET SPECIFIC CONFIG # config.exs use Mix.Config import_config "#{Mix.Project.config[:target]}.exs" Multi-Target
- 46. CHANGING TARGETS NERVES_TARGET=linkit mix deps.get export NERVES_TARGET=linkit mix deps.get mix deps.get # @target System.get_env("NERVES_TARGET") || "linkit" Multi-Target
- 47. Systems Linkit Smart Raspberry Pi 3
- 49. Linkit Smart
- 50. LINKIT SMART
- 52. LINKIT SMART 1.5
- 53. LinkIt Smart 7688 Flash ▸ 32 MB NAND Flash ▸ Bootloader and Linux kernel stored here ▸ LinkIt bootloader doesn’t support FTL so don’t update too many times ▸ Linux mtd driver provides access (/dev/mtdblock1, etc.) ▸ MicroSD card ▸ Root filesystems ▸ Application data
- 54. Typical Nerves Flash layout Master Boot Record Bootloaders Root Filesystem A Read-only Root Filesystem B Read-only Application Data Read-write Linux kernel Erlang C libraries and apps OTP release App settings Database Logs Other files
- 55. Flash layout Master Boot Record Root Filesystem A Read-only Root Filesystem B Read-only Application Data Read-write Erlang C libraries and apps OTP release App settings Database Logs Other files Bootloader Linux Kernel
- 56. The Console ▸ Black - Ground ▸ Red - 5v ▸ White - RX ▸ Green - TX
- 57. The Console ▸ Black - Ground ▸ Red - 5v ▸ White(RX) - TX ▸ Green(TX) - RX Don’t worry about accidentally swapping RX and TX. If nothing shows up on the console, just swap them.
- 58. The Console ▸ Baud: 57600 ▸ Bits: 8 ▸ Parity: None ▸ Stop Bits: 1
- 59. The Console $ picocom -b 57600 /dev/tty.usbserial
- 60. BURN BOOTLOADER ▸ Connect a 3.3V FTDI cable (GND, RX, and TX) to the LinkIt Smart. Power up the LinkIt Smart and verify that you can see text and type. You should be interacting with the default OpenWRT firmware. ▸ Remove power from the LinkIt Smart LinkIt Smart Prep
- 61. BURN BOOTLOADER ▸ Plug the USB Flash drive into the LinkIt Smart via the On- the-go cable. Make sure that it's plugged into the USB Host connector. ▸ Press the 'b' key repeatedly on the serial port while rebooting the LinkIt Smart. ▸ Stop when you see that it is programming the Flash. LinkIt Smart Prep
- 62. BURN LINUX KERNEL ▸ Press the '5' key repeatedly on the serial port while rebooting the LinkIt Smart. ▸ Stop when you see that it is programming the Flash. ▸ Should be looking for rootfs on SD LinkIt Smart Prep
- 64. RECAP ▸ What is Nerves ▸ Definitions ▸ Differences In Targets ▸ Preparing your Host ▸ Preparing the Target Title
- 66. ▸ Interfacing with Hardware ▸ Boot to IEx ▸ Pin Muxing ▸ Blinky with elixir_ale ▸ Blinky with Firmata and Arduino What are we going to Do?
- 68. Booting to IEx $ mix nerves.new console --target linkit $ cd console $ mix deps.get $ mix firmware $ mix firmware.burn https://github.com/mobileoverlord/console Fast track
- 69. Code it up
- 70. Adding IEx Helpers defmodule Console.IExHelpers do def cat(file) do File.read!(file) |> IO.puts end end
- 71. Adding IEx Helpers # config/rootfs-additions/etc/iex.exs import Console.IExHelpers
- 72. Adding IEx Helpers # config/config.exs config :nerves, :firmware, rootfs_additions: "config/rootfs-additions"
- 73. Adding IEx Helpers # rel/vm.args ## Start the Elixir shell -noshell -user Elixir.IEx.CLI -extra --no-halt +iex --dot-iex /etc/iex.exs
- 74. Adding IEx Helpers $ mix firmware $ mix firmware.burn
- 75. Adding IEx Helpers iex(1)> cat "/etc/iex.exs" import Console.IExHelpers :ok
- 76. PIN MUXING 2.2
- 77. The problem GPIO SPI I2C Camera In Ethernet Timer PWM MMC Display More pins than fit on a chip! DRAM Power
- 78. A layer of indirection GPIO SPI I2C Camera In Ethernet Timer PWM MMC Display DRAM Power Pin mux Physical pins
- 79. Beaglebone Black (TI AM335x) http://www.embedded-things.com/bbb/beaglebone-black-pin-mux-spreadsheet/
- 81. ▸ Bootloader ▸ Some pins have to configured as early as possible ▸ Usually only deal with this on custom boards ▸ Linux kernel device tree ▸ Textual description of the hardware configuration ▸ Compiled down and loaded early in the Linux boot process ▸ Device tree overlays may be loaded after boot (but not supported on the LinkIt Smart) ▸ Custom programs Configuring pinmux’d processors
- 82. ▸ Device tree ▸ linux-4.4.14/arch/mips/boot/dts/ralink/LINKIT7688.dts ▸ Compiled to LINKIT7688.dtb ▸ Usermode app - pinmux ▸ https://github.com/nerves-project/nerves_system_linkit/ tree/develop/package/mtk-linkit ▸ Invoke on the Linkit Smart as: LinkIt Smart pinmux configuration /usr/bin/pinmux set ephy gpio
- 86. Host Tools $ mix nerves.new blinky_ale --target linkit https://github.com/mobileoverlord/blinky_ale Fast track
- 87. MIX FILE defmodule BlinkyAle.Mixfile do … def application do [mod: {BlinkyAle, []}, applications: [:logger, :elixir_ale]] end def deps do [{:nerves, "~> 0.3.0"}, {:elixir_ale, "~> 0.5.6"}] end end Blinky Elixir Ale
- 88. defmodule BlinkyAle do use Application # See http://elixir-lang.org/docs/stable/elixir/Application.html # for more information on OTP Applications def start(_type, _args) do import Supervisor.Spec, warn: false # Define workers and child supervisors to be supervised children = [ worker(Task, [fn -> blink end], restart: :transient), ] # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html # for other strategies and supported options opts = [strategy: :one_for_one, name: BlinkyAle.Supervisor] Supervisor.start_link(children, opts) end ... end Blinky Elixir Ale
- 89. defmodule BlinkyAle do ... def blink do :os.cmd '/usr/bin/pinmux set ephy gpio' {:ok, pid} = Gpio.start_link(43, :output) blink_forever(pid) end def blink_forever(pid) do Gpio.write(pid, 1) :timer.sleep(1000) Gpio.write(pid, 0) :timer.sleep(1000) blink_forever(pid) end end Blinky Elixir Ale
- 90. Code it up
- 92. Arduino D13 LED Arduino Serial / Power
- 93. Running on the Host // SimpleFirmata.ino Firmata.begin(57600); while (!Serial) { ; }
- 94. Arduino Firmata ▸ File -> Examples -> Firmata -> StandardFirmata
- 95. Write to the Arduino
- 96. Running on the Host $ mix new blinky_firmata_host https://github.com/mobileoverlord/blinky_firmata_host Fast track
- 97. Running on the Host defmodule BlinkyFirmataHost.Mixfile do ... def application do [applications: [:logger, :firmata], mod: {BlinkyFirmataHost, []}] end defp deps do [{:firmata, github: "mobileoverlord/firmata"}] end end
- 98. Running on the Host defmodule BlinkyFirmataHost.Protocol do use GenServer use Firmata.Protocol.Mixin alias Firmata.Board def start_link(tty, opts []) do GenServer.start_link(__MODULE__, [tty, opts], name: __MODULE__) end def init([tty, opts]) do IO.puts "Init" {:ok, board} = Board.start_link(tty, opts) {:ok, %{ board: board }} end ... end
- 99. Running on the Host defmodule BlinkyFirmataHost.Protocol do ... def handle_info({:firmata, {:pin_map, _pin_map}}, s) do IO.puts "Set Pin Map" Board.set_pin_mode(s.board, 13, @output) send(self, {:blink, 1}) {:noreply, s} end def handle_info({:blink, state}, s) do IO.puts "Blink" Board.digital_write(s.board, 13, state) state = if state == 1, do: 0, else: 1 Process.send_after(self, {:blink, state}, 1000) {:noreply, s} end def handle_info(_, s) do {:noreply, s} end end
- 100. Running on the Host Interactive Elixir (1.3.2) - press Ctrl+C to exit (type h() ENTER for help) iex(1)> Nerves.UART.enumerate %{"/dev/cu.Bluetooth-Incoming-Port" => %{}, "/dev/cu.MyQC-SPPDev" => %{}, "/dev/cu.MyQC-SPPDev-1" => %{}, "/dev/cu.usbmodem1421" => %{manufacturer: "MediaTek Labs", product_id: 43777, vendor_id: 3725}}
- 101. Running on the Host iex(2)> BlinkyFirmataHost.Protocol.start_link "/dev/cu.usbmodem1421" Init {:ok, #PID<0.156.0>} Set Pin Map Blink
- 102. It Blinks!
- 103. Running on the Target // StandardFirmata.ino // Connecting from LinkIt Serial1.begin(57600); Firmata.begin(Serial1); // Connecting from Host // Firmata.begin(57600); // while (!Serial) { // ; // // }
- 104. Write to the Arduino
- 105. Running on the Target $ mix nerves.new blinky_firmata --target linkit https://github.com/mobileoverlord/blinky_firmata Fast track
- 106. Running on the Target defmodule BlinkyFirmata.Mixfile do ... def application do [applications: [:logger, :firmata], mod: {BlinkyFirmata, []}] end defp deps do [{:nerves, "~> 0.3.0"}, {:firmata, github: "mobileoverlord/firmata"}] end end
- 107. Running on the Target defmodule BlinkyFirmata.Protocol do use GenServer use Firmata.Protocol.Mixin alias Firmata.Board def start_link(tty, opts []) do GenServer.start_link(__MODULE__, [tty, opts], name: __MODULE__) end def init([tty, opts]) do IO.puts "Init" {:ok, board} = Board.start_link(tty, opts) {:ok, %{ board: board }} end ... end
- 108. Running on the Target defmodule BlinkyFirmata.Protocol do ... def handle_info({:firmata, {:pin_map, _pin_map}}, s) do IO.puts "Set Pin Map" Board.set_pin_mode(s.board, 13, @output) send(self, {:blink, 1}) {:noreply, s} end def handle_info({:blink, state}, s) do IO.puts "Blink" Board.digital_write(s.board, 13, state) state = if state == 1, do: 0, else: 1 Process.send_after(self, {:blink, state}, 1000) {:noreply, s} end def handle_info(_, s) do {:noreply, s} end end
- 109. Running on the Target defmodule BlinkyFirmata do use Application def start(_type, _args) do import Supervisor.Spec, warn: false # Define workers and child supervisors to be supervised children = [ worker(BlinkyFirmata.Protocol, ["ttyS0"]), ] # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html # for other strategies and supported options opts = [strategy: :one_for_one, name: BlinkyFirmata.Supervisor] Supervisor.start_link(children, opts) end end
- 110. Running on the Target $ mix firmware $ mix firmware.burn
- 111. Boot it up
- 112. It Blinks!
- 113. ▸ Elixir Ale ▸ Firmata ▸ Ports ▸ When to use which strategy Recap
- 114. Building the Badge SECTION 3
- 115. ▸ Building the Badge ▸ Project Layout ▸ Arduino and Firmata ▸ Connecting to Twitter ▸ Web Interfaces What are we going to Do?
- 116. PROJECT LAYOUT 3.1
- 117. UMBRELLA ▸ Organize facets of code in our project for isolation ▸ Ability to run aspects on Host Project Layout
- 118. Project Layout $ mix new badge --umbrella └── badge ├── README.md ├── apps ├── config │ └── config.exs └── mix.exs https://github.com/mobileoverlord/badge Fast track
- 119. Project Layout $ cd badge/apps $ mix nerves.new badge_fw --target linkit $ mix new badge_lib ├── badge_fw └── badge_lib
- 120. Project Layout # apps/badge_fw/mix.exs def application do [mod: {BadgeFw, []}, applications: [:logger, :badge_lib]] end def deps do [{:nerves, "~> 0.3.0"}, {:badge_lib, in_umbrella: true}] end
- 121. Code it up
- 122. Project Layout # apps/badge_fw $ mix deps.get $ mix firmware
- 123. Project Layout # apps/badge_fw $ mix deps.get $ mix firmware ** (UndefinedFunctionError) function :relx.do/2 is undefined (module :relx is not available) If you are at the top of the umbrella
- 124. INITIALIZATION 3.2
- 125. Initialization # apps/badge_fw/mix.exs def application do [mod: {BadgeFw, []}, applications: [:logger, :badge_lib, :nerves_interim_wifi]] end def deps do [{:nerves, "~> 0.3.0"}, {:nerves_interim_wifi, "~> 0.1"}, {:badge_lib, in_umbrella: true}] end # apps/badge_fw $ mix deps.get
- 126. Initialization # apps/badge_fw/lib/badge_fw.ex defmodule BadgeFw do use Application alias Nerves.InterimWiFi, as: WiFi def start(_type, _args) do import Supervisor.Spec, warn: false :os.cmd('modprobe mt7603e') # Define workers and child supervisors to be supervised children = [ worker(Task, [fn -> network end], restart: :transient), ] # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html # for other strategies and supported options opts = [strategy: :one_for_one, name: BadgeFw.Supervisor] Supervisor.start_link(children, opts) end def network do wlan_config = Application.get_env(:badge_fw, :wlan0) WiFi.setup "wlan0", wlan_config end end
- 127. Initialization # apps/badge_fw/config/config.exs use Mix.Config config :badge_fw, :wlan0, ssid: "Nerves", key_mgmt: :"WPA-PSK", psk: "nervesnet"
- 128. Test it out :inet.gethostbyname 'nerves-project.org' $ mix firmware $ mix firmware.burn Initialization
- 129. Initialization # apps/badge_fw/mix.exs def application do [mod: {BadgeFw, []}, applications: [:logger, :badge_lib, :nerves_interim_wifi, :nerves_ntp]] end def deps do [{:nerves, "~> 0.3.0"}, {:nerves_interim_wifi, "~> 0.1"}, {:nerves_ntp, "~> 0.1"}, {:badge_lib, in_umbrella: true}] end # apps/badge_fw $ mix deps.get
- 130. # apps/badge_fw/config/config.exs config :nerves_ntp, :ntpd, "/usr/sbin/ntpd" config :nerves_ntp, :servers, [ "0.pool.ntp.org", "1.pool.ntp.org", "2.pool.ntp.org", "3.pool.ntp.org" ] Initialization
- 131. # badge_fw/rel/vm.args -sname badge -setcookie nerves ## Start the Elixir shell -noshell -user Elixir.IEx.CLI -extra --no-halt Initialization Enable distributed Erlang
- 132. remsh iex --sname host --cookie nerves --remsh badge@nerves-244a
- 133. FIRMATA ARDUINO 3.3
- 134. Connecting the Components Vibration motor Display D9 I2C
- 135. $ git clone https://github.com/mobileoverlord/badge_firmata Arduino Firmata
- 136. # badge_lib/mix.exs def application do [applications: [:logger, :firmata]] end defp deps do [{:firmata, github: "mobileoverlord/firmata"}] end Arduino Firmata $ mix deps.get
- 138. Write to the Arduino
- 139. Arduino Firmata defmodule BadgeLib.Firmata do use GenServer use Firmata.Protocol.Modes alias Firmata.Board, as: Board def start_link(opts []) do port = opts[:port] || "ttyS0" speed = opts[:speed] || 57600 serial_opts = [speed: speed] GenServer.start_link(__MODULE__, [port, serial_opts], name: __MODULE__) end def init([port, serial_opts]) do {:ok, board} = Board.start_link(port, serial_opts) {:ok, %{ board: board }} end ... end
- 140. Arduino Firmata defmodule BadgeLib.Firmata do ... def handle_info({:firmata, {:pin_map, _pin_map}}, s) do {:noreply, s} end def handle_info(_, s) do {:noreply, s} end end
- 141. Arduino Firmata defmodule BadgeLib.Firmata do use GenServer use Firmata.Protocol.Modes alias Firmata.Board, as: Board @high 1 @low 0 @vibration_pin 9 def start_link(opts []) def vibrate(state @high) do GenServer.call(__MODULE__, {:vibrate, state}) end ... end
- 142. Arduino Firmata defmodule BadgeLib.Firmata do ... def handle_call({:vibrate, state}, _from, s) do Board.digital_write(s.board, @vibration_pin, state) {:reply, :ok, s} end def handle_info({:firmata, {:pin_map, _pin_map}}, s) do Board.set_pin_mode(s.board, @vibration_pin, @output) {:noreply, s} end end
- 143. Running on the host Firmata.begin(57600); while (!Serial) { ; }
- 144. Running on the host Firmata.begin(57600); while (!Serial) { ; } Interactive Elixir (1.3.2) - press Ctrl+C to exit (type h() ENTER for help) iex(1)> Nerves.UART.enumerate %{"/dev/cu.Bluetooth-Incoming-Port" => %{}, "/dev/cu.MyQC-SPPDev" => %{}, "/dev/cu.MyQC-SPPDev-1" => %{}, "/dev/cu.usbmodem1421" => %{manufacturer: "MediaTek Labs", product_id: 43777, vendor_id: 3725}}
- 145. Running on the host %{"/dev/cu.Bluetooth-Incoming-Port" => %{}, "/dev/cu.MyQC-SPPDev" => %{}, "/dev/cu.MyQC-SPPDev-1" => %{}, "/dev/cu.usbmodem1421" => %{manufacturer: "MediaTek Labs", product_id: 43777, vendor_id: 3725}} iex(2)> BadgeLib.Firmata.start_link(port: "/dev/cu.usbmodem1421")
- 146. Running on the host iex(3)> BadgeLib.Firmata.vibrate
- 147. Arduino Firmata defmodule BadgeLib.Firmata do ... @vibration_pulse 300 @vibration_times 7 def vibrate_pulse() do GenServer.call(__MODULE__, :vibrate_pulse) end ... end
- 148. Arduino Firmata defmodule BadgeLib.Firmata do ... def handle_call(:vibrate_pulse, _from, s) do send(self, {:vibrate_pulse, 0, 1}) {:reply, :ok, s} end def handle_info({:vibrate_pulse, @vibration_times, _},s) do Board.digital_write(s.board, @vibration_pin, @low) {:noreply, s} end def handle_info({:vibrate_pulse, times, state}, s) do Board.digital_write(s.board, @vibration_pin, state) state = if state == 0, do: 1, else: 0 Process.send_after(self, {:vibrate_pulse, times + 1, state}, @vibration_pulse) {:noreply, s} end end
- 149. Running on the host
- 150. Arduino Firmata defmodule BadgeLib.Firmata do ... @display_clear 0x81 @display_text 0x82 @display_time 20_000 def text(message) do GenServer.call(__MODULE__, {:text, message}) end def clear() do GenServer.call(__MODULE__, :clear) end ... end
- 151. Arduino Firmata defmodule BadgeLib.Firmata do ... def handle_call({:text, message}, _from, s) do Board.sysex_write(s.board, @display_clear, "") resp = Board.sysex_write(s.board, @display_text, message) Process.send_after(self, :clear_display, @display_time) {:reply, {:ok, resp}, s} end def handle_call(:clear, _from, s) do resp = Board.sysex_write(s.board, @display_clear, "") {:reply, {:ok, resp}, s} end def handle_info(:clear_display, s) do Board.sysex_write(s.board, @display_clear, "") {:noreply, s} end ... end
- 152. Running on the host
- 153. Arduino Firmata defmodule BadgeFw do use Application alias Nerves.InterimWiFi, as: WiFi def start(_type, _args) do import Supervisor.Spec, warn: false :os.cmd('modprobe mt7603e') # Define workers and child supervisors to be supervised children = [ worker(Task, [fn -> network end], restart: :transient), worker(BadgeLib.Firmata, []), ] # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html # for other strategies and supported options opts = [strategy: :one_for_one, name: BadgeFw.Supervisor] Supervisor.start_link(children, opts) end ... end
- 154. Running on the target
- 155. TWITTER 3.4
- 156. Connecting to Twitter # badge_lib/mix.exs def application do [applications: [:logger, :firmata, :oauth, :extwitter]] end defp deps do [{:firmata, github: "mobileoverlord/firmata"}, {:oauth, github: "tim/erlang-oauth"}, {:extwitter, "~> 0.6"}] end
- 157. Connecting to Twitter defmodule BadgeFw.Worker do use GenServer def start_link(opts []) do GenServer.start_link(__MODULE__, [], opts) end def init([]) do BadgeLib.Firmata.clear() {:ok, %{}} end end
- 158. defmodule BadgeFw do use Application alias Nerves.InterimWiFi, as: WiFi def start(_type, _args) do import Supervisor.Spec, warn: false :os.cmd('modprobe mt7603e') # Define workers and child supervisors to be supervised children = [ worker(Task, [fn -> network end], restart: :transient), worker(BadgeLib.Firmata, []), worker(BadgeFw.Worker, []), ] # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html # for other strategies and supported options opts = [strategy: :one_for_one, name: BadgeFw.Supervisor] Supervisor.start_link(children, opts) end ... end Connecting to Twitter
- 159. defmodule BadgeFw.Worker do use GenServer @hashtag "#NervesBadge" @handle "@ElixirConf" @interval 25_000 def init([]) do BadgeLib.Firmata.clear() Process.send_after(self, :update, @interval) {:ok, %{last: {nil, nil}}} end end Connecting to Twitter
- 160. def handle_info(:update, %{last: {lhash, luser}} = s) do {hash, user} = {@handle, @hashtag} new_hash = get_tweet(hash) new_user = get_tweet(user) last = cond do new_hash != lhash -> display_tweet(new_hash) {new_hash, luser} new_user != luser -> display_tweet(new_user) {lhash, new_user} true -> {lhash, luser} end Process.send_after(self, :update, @interval) {:noreply, %{s | last: last}} end Connecting to Twitter
- 161. def get_tweet(search) do case ExTwitter.search(search, [count: 1]) do [tweet] -> tweet _ -> nil end end def display_tweet(tweet) do IO.puts "display tweet" BadgeLib.Utf8ToASCII.convert(tweet.text) |> BadgeLib.Firmata.text BadgeLib.Firmata.vibrate_pulse end Connecting to Twitter
- 162. defmodule BadgeLib.Utf8ToASCII do def convert(string), do: convert(string, <<>>) def convert(<<c::utf8, rest::binary>>, result) when c <= 127 do convert(rest, result <> <<c::utf8>>) end def convert(<<_::utf8, rest::binary>>, result) do convert(rest, result) end def convert(<<>>, result) do result end end Connecting to Twitter
- 163. # badge_fw/config/config.exs config :extwitter, :oauth, [ consumer_key: "vnBfkubUmv10QRcQjFU3lXKin", consumer_secret: "XUk3fsulkfraaapUyMOfnVRtd8fXdlkKMQvhjDv5nnEVrsk7yA", access_token: System.get_env("TWITTER_ACCESS_TOKEN"), access_token_secret: System.get_env("TWITTER_ACCESS_TOKEN_SECRET") ] Connecting to Twitter
- 164. Running on the target
- 165. WEB INTERFACES 3.5
- 166. Web Interfaces $ cd badge/apps $ git clone https://github.com/lancehalvorsen/badge_settings
- 167. # badge_fw/mix.exs def application do [mod: {BadgeFw, []}, applications: [:logger, :badge_lib, :nerves_interim_wifi, :nerves_ntp, :badge_settings]] end def deps do [{:nerves, "~> 0.3.0"}, {:nerves_interim_wifi, "~> 0.1"}, {:nerves_ntp, "~> 0.1"}, {:badge_lib, in_umbrella: true}, {:badge_settings, in_umbrella: true}] end Web Interfaces
- 168. Web Interfaces # badge_fw/config/config.exs config :badge_settings, :nerves_settings, %{ settings_file: "/root/nerves_settings.txt", device_name: "My Awesome Device", application_password: System.get_env("BADGE_CONFIG_PASSWORD") || "nerves_rulz!" } config :badge_settings, BadgeSettings.Endpoint, url: [host: "0.0.0.0"], http: [port: 80], secret_key_base: "R02jL0Vi+tFH7YOecTua/oc0b2dETOQT8/ Sg9dD56EDKqmd8jRAdqa0CyZ7tOFIt", render_errors: [view: BadgeSettings.ErrorView, accepts: ~w(html json)], server: true, pubsub: [name: BadgeSettings.PubSub, adapter: Phoenix.PubSub.PG2]
- 169. Web Interfaces $ cd apps/badge_settings $ mix deps.get $ npm install $ ./node_modules/brunch/bin/brunch build --production $ MIX_ENV=prod mix phoenix.digest
- 170. Running on the host
- 171. Running on the target
- 173. Web Interfaces def network do wlan_config = case settings do {:ok, settings} -> [psk: settings.password, ssid: settings.ssid] _ -> Application.get_env(:badge_fw, :wlan0) end WiFi.setup "wlan0", wlan_config end def settings do settings_file = Application.get_env(:badge_settings, :nerves_settings).settings_file case File.read(settings_file) do {:error, :enoent} = error -> error {:ok, ""} -> {:error, :empty} {:ok, contents} -> unencoded = :erlang.binary_to_term(contents) {:ok, unencoded} end end
- 174. Web Interfaces def handle_info(:update, %{last: {lhash, luser}} = s) do {hash, user} = case BadgeFw.settings do {:ok, settings} -> {Map.get(settings, :handle), Map.get(settings, :hashtag)} _ -> {@handle, @hashtag} end ... end
- 175. RECAP ▸ Project Layout ▸ Initialization ▸ Interfacing with Arduino ▸ Connecting to Services ▸ Web Interfaces with Phoenix Building the Badge
- 177. ▸ Advanced Configuration ▸ Modifying a Nerves System ▸ Initialization with erlinit ▸ Firmware Updates ▸ Licensing What are we going to Do?
- 179. Reasons to make your own system ▸ Add a library or application that can’t be built using mix ▸ Postgres ▸ Qt ▸ Add a Linux kernel module or patch the kernel ▸ WiFi drivers ▸ Audio, webcams, USB peripherals ▸ Patch or change the bootloader ▸ Enable a Busybox command ▸ Likely if you need to run a shell script ▸ Consider re-implementing in Elixir
- 180. Reasons NOT to make your own system ▸ Add files to the root filesystem ▸ These can be added via the rootfs-additions mechanism ▸ Change the iex terminal tty or alter how Erlang is started ▸ Create your own erlinit.config for your project ▸ Add or remove files from the firmware update files ▸ Create your own fwup.conf for your project ▸ Summary: Try to avoid modifying systems too much since it will take away the benefits of working with the Elixir tools
- 181. Prereqs to working with systems ▸ Concepts ▸ Buildroot ▸ Linux kernel configuration ▸ Busybox ▸ Build and deploy requirements ▸ Linux (native, VM, or Docker) ▸ Someplace to put the system image since it’s too large for hex.pm
- 182. Buildroot ▸ Toolchain, bootloader, kernel, root filesystem builder for embedded Linux ▸ Cross-compiled ▸ Support for building ~1800 programs and libraries ▸ Menu system for enabling and configuring packages ▸ Uses Makefiles, but not necessary to know make even to add packages ▸ Very well documented
- 183. World views ▸ Buildroot normally is the top-level project that builds firmware images ▸ Nerves uses Buildroot to produce the system images that later get combined with OTP releases ▸ Consequences ▸ Erlang packages in Buildroot aren’t usable (no ejabberd) ▸ Nerves images are much smaller due to not including all (or most) of OTP ▸ For most development, Nerves builds are faster and can be run on OSX
- 184. Defconfigs and .configs ▸ Anything using Kconfig to manage configuration options uses these (Linux, Buildroot, Busybox) ▸ .config ▸ Found in the root of the build directory for the project ▸ Has the values for ALL options – hidden, derived, etc. ▸ defconfig ▸ Subset of .config with only non-default options ▸ Usually stored in source control ▸ make savedefconfig
- 185. Activity: Start a system build ▸ Clone one of the official Nerves system images ▸ https://github.com/nerves-project/nerves_system_* ▸ Method 1 – official builds ▸ cd nerves_system_foo; mix deps.get; mix compile ▸ CTRL-C to stop (mix clean may be needed to start over) ▸ Method 2 – easier for development ▸ Clone https://github.com/nerves-project/nerves_system_br ▸ nerves_system_br/create-build.sh nerves_system_foo/nerves_defconfig out ▸ cd out; make
- 186. Activity: Compile in a new package ▸ Go to the out directory from the last activity ▸ make menuconfig ▸ Find and enable postgresql ▸ Hint: Type the “/” key to search for postgresql. Press the number ▸ While you’re in menuconfig, take a look around ▸ Exit menuconfig. Be sure to save! ▸ Inspect .config and see that BR2_PACKAGE_POSTGRESQL is enabled ▸ make savedefconfig ▸ Inspect nerves_system_foo/nerves_defconfig has POSTGRESQL enabled ▸ Run make if you have time
- 187. The Linux kernel ▸ Why Linux? Best device driver support for embedded ▸ Nerves uses a trimmed down Linux kernel to keep the image size reasonable ▸ Many device drivers compiled into the kernel so no need to load them at initialization ▸ Some device drivers still compiled as modules ▸ Module parameters unknown until runtime ▸ Don’t work when compiled into the kernel ▸ More generic images
- 188. Activity: Enable a device driver ▸ Go to the out directory from before ▸ make linux-menuconfig ▸ Enable support for USB->serial adapters – called USB Modem (CDC ACM) support in the kernel ▸ Use “/” to search for it if you’re not sure where it is ▸ Exit and save ▸ Inspect build/linux-x.y.z/.config to see that the option was saved ▸ make linux-savedefconfig ▸ Inspect build/linux-x.y.z/defconfig to verify the option again ▸ cp build/linux-x.y.z/defconfig to the Linux defconfig for the Nerves system. This is usually called linux-x.y.defconfig
- 189. Busybox ▸ Provides tons of Unix apps in one small binary ▸ ls, sh, dd, ps, find, cat, tail, tar, cd, mkdir, etc. ▸ ntpd, dhcpc ▸ vi (sorry, no emacs) ▸ Ideally, Nerves would not have to use Busybox ▸ Wishlist: project that adds common shell commands to the IEx shell and improves OS process inspection ▸ Removing Busybox is not trivial so it will be with us for a while
- 190. Activity: Modify the Busybox config ▸ Go to the out directory from before ▸ make busybox-menuconfig ▸ Enable the ping utility, exit and save ▸ Verify that CONFIG_PING is enabled in build/busybox-1.x.y/.config ▸ If your system overrides the default busybox configuration, copy the new one on top of it ▸ If not, ▸ Copy build/busybox-1.x.y/.config to ../busybox.config ▸ make menuconfig ▸ Set the Busybox configuration to ${NERVES_DEFCONFIG_DIR}/ busybox.config ▸ make savedefconfig
- 191. Using your custom Nerves system ▸ Go to the out directory from before ▸ export NERVES_SYSTEM=$PWD ▸ Now go to your Elixir project and run mix
- 192. Publishing a custom Nerves system ▸ What you’ll need ▸ Someplace to hold your nerves_system_xyz ▸ Someplace to hold the built tarball for the system ▸ GitHub supports both - attach the tarball to a release ▸ hex.pm only supports the source repository
- 193. nerves.exs config :nerves_system_linkit, :nerves_env, type: :system, version: version, mirrors: [ "https://github.com/nerves-project/nerves_system_linkit/releases/ download/v#{version}/nerves_system_linkit-v#{version}.tar.gz", "https://s3.amazonaws.com/nerves/artifacts/nerves_system_linkit- #{version}.tar.gz"], …
- 194. Final steps ▸ Go back to your system’s out directory ▸ make system ▸ Publish the created tarball ▸ Publish the source on hex.pm or git ▸ Let everyone know to reference your Nerves system image in their mix.exs
- 195. ERLINIT 4.2
- 196. erlinit ▸ Replacement for /sbin/init that starts the Erlang virtual machine ▸ Basic initialization of the Linux user land ▸ Loopback network connection ▸ Mounts /tmp, /proc, /sys ▸ Configures the tty ▸ Configuration stored in /etc/erlinit.conf ▸ Can be overridden by passing parameters to the Linux kernel from the bootloader
- 197. erlinit debugging options ▸ --verbose ▸ --hang-on-exit ▸ Useful to capture error messages when the VM exits ▸ --run-on-exit /bin/sh ▸ Drop into a shell if the VM exits ▸ Exiting the shell reboots or hangs ▸ --warn-unused-tty ▸ erlinit will tell you what options to pass it to use the shell on the terminal you’re looking at
- 198. erlinit features ▸ Mount filesystems ▸ Configure a unique hostname ▸ --hostname-pattern and --uniqueid-exec ▸ Nerves uses fhunleth/boardid to read serial numbers ▸ Wrap the launch of the Erlang VM in another program ▸ --alternate-exec ▸ Perform some custom system-specific initialization that can’t be done in Erlang or Elixir ▸ Capture the terminal with dtach to route it to a GUI ▸ Run the Erlang VM as a regular user
- 199. erlinit pitfalls ▸ Running shell scripts to initialize the system ▸ Move initialization to Elixir to take advantage of OTP supervision ▸ Currently no standard way of handing system initialization in Nerves ▸ Assuming writable filesystems always can be mounted ▸ Failures happen – must be handled in Elixir ▸ erlinit can’t report errors so Elixir must check
- 200. FIRMWARE UPDATE 4.3
- 201. fwup ▸ Firmware update packaging and application ▸ Packages ▸ Zip-formatted archives ▸ Metadata ▸ All data files protected by cryptographic hashes ▸ Packages can be cryptographically signed ▸ Very simple scripts supported (lack of functionality is a feature)
- 202. fwup processing Master Boot Record FAT Boot partition Root Filesystem A Read-only Root Filesystem B Read-only Application Data Read-write rootfs.img uImage other files on_init on_finish .fw file fwup processing 1 2 3 4 5
- 203. Anatomy of a fwup.conf file ▸ Resources ▸ Files that are included as part of the zip archive ▸ Not required to be used when upgrading ▸ Tasks ▸ Instructions for applying updates ▸ Only one task is run at a time ▸ Tasks may have conditions for when they’re run ▸ Common task names: “complete” and “upgrade”
- 204. LinkIt Smart fwup.conf # Let the rootfs have room to grow up to 64 MiB and align # it to the nearest 1 MB boundary define(ROOTFS_A_PART_OFFSET, 2048) define(ROOTFS_A_PART_COUNT, 131072) define(ROOTFS_B_PART_OFFSET, 133120) define(ROOTFS_B_PART_COUNT, 131072) # Application partition # NOTE: Keep the total amount used under 1.78 GiB so that # everything fits in the "2 GB" eMMC. define(APP_PART_OFFSET, 264192) define(APP_PART_COUNT, 1048576) https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf
- 205. LinkIt Smart fwup.conf # Firmware metadata meta-product = "Nerves Firmware" meta-description = "" meta-version = ${NERVES_SDK_VERSION} meta-platform = "linkit" meta-architecture = "mips" meta-author = "Frank Hunleth" https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf
- 206. LinkIt Smart fwup.conf file-resource rootfs.img { host-path = ${ROOTFS} } file-resource uImage { host-path = "${NERVES_SYSTEM}/images/uImage" assert-size-lte = 30720 # 15 MiB } https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf
- 207. LinkIt Smart fwup.conf mbr mbr-a { partition 0 { block-offset = ${ROOTFS_A_PART_OFFSET} block-count = ${ROOTFS_A_PART_COUNT} type = 0x83 # Linux } partition 1 { block-offset = ${APP_PART_OFFSET} block-count = ${APP_PART_COUNT} type = 0xc # FAT32 } # partition 2 and 3 are unused } https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf
- 208. LinkIt Smart fwup.conf # This firmware task writes everything to the destination media task complete { on-init { mbr_write(mbr-a) } on-resource rootfs.img { # write to the first rootfs partition raw_write(${ROOTFS_A_PART_OFFSET}) } on-finish { fat_mkfs(${APP_PART_OFFSET}, ${APP_PART_COUNT}) fat_setlabel(${APP_PART_OFFSET}, "APPDATA") } } https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf
- 209. LinkIt Smart fwup.conf task upgrade.a { # This task upgrades the A partition require-partition-offset(0, ${ROOTFS_B_PART_OFFSET}) on-resource rootfs.img { # write to the first rootfs partition raw_write(${ROOTFS_A_PART_OFFSET}) } on-finish { # Switch over to boot the new rootfs mbr_write(mbr-a) } } https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf
- 210. LinkIt Smart fwup.conf https://github.com/nerves-project/nerves_system_linkit/blob/develop/fwup.conf task upgrade.b { # This task upgrades the B partition require-partition-offset(0, ${ROOTFS_A_PART_OFFSET}) on-resource rootfs.img { # write to the first rootfs partition raw_write(${ROOTFS_B_PART_OFFSET}) } on-finish { # Switch over to boot the new firmware mbr_write(mbr-b) } }
- 211. FAT filesystem commands Command Description fat_mkfs(block_offset, block_count) Create a FAT file system fat_write(block_offset, filename) Write the resource to the file system fat_mv(block_offset, oldname, newname) Rename a file fat_rm(block_offset, filename) Delete a file fat_mkdir(block_offset, filename) Create a directory fat_touch(block_offset, filename) Create an empty file if the file doesn't exist
- 212. LICENSING 4.4
- 213. Shipping Nerves - Licensing ▸ Buildroot infrastructure in Nerves can aid process ▸ make legal-info ▸ Other licenses ▸ nerves-toolchain ▸ gcc ▸ crosstool-ng ▸ All of your mix dependencies legal-info ├── buildroot.config ├── host-licenses │ ├── autoconf │ │ ├── COPYING.EXCEPTION │ │ └── COPYINGv3 │ └── ... │ └── README ├── host-licenses.txt ├── host-manifest.csv ├── host-sources ├── licenses │ ├── busybox │ │ └── LICENSE │ ├── erlang │ │ └── LICENSE.txt │ └── ... ├── licenses.txt ├── manifest.csv ├── README └── sources ├── boardid-v0.4.0.tar.gz ├── busybox-1.24.1.tar.bz2 ├── ... └── zlib-1.2.8.tar.xz
- 214. Elixir Conf 2016 Nerves: Connected beyond the Node Thursday 1:30 PM - 2:15 PM Track 1 Justin Schneck Building "learn to touch type" glove with Elixir and Arduino2:15 PM - 3:00 PM Track 2 Tetiana Dushenkivska Nerves + Phoenix Saves a Father's Sanity! Friday 1:30 PM - 2:15 PM Track 2 Joel Byler The Joy of Connecting Elixir to the Physical World3:30 PM - 4:15 PM Track 1 Frank Hunleth Keynote4:30 PM - 5:30 PM Boyd Multerer
- 215. Elixir Conf 2016 Thank You & Nerves