2024-04-05

The first step is to install the arduino-cli.

sudo pacman -S arduino-cli

Create a local configuration file. This is not necessary, but it does help making commands less lengthy.

arduino-cli config init
# Config file written to: /home/x/.arduino15/arduino-cli.yaml

The initial file looks like this:

board_manager:
    additional_urls: []
build_cache:
    compilations_before_purge: 10
    ttl: 720h0m0s
daemon:
    port: "50051"
directories:
    data: /home/x/.arduino15
    downloads: /home/x/.arduino15/staging
    user: /home/x/Arduino
library:
    enable_unsafe_install: false
logging:
    file: ""
    format: text
    level: info
metrics:
    addr: :9090
    enabled: true
output:
    no_color: false
sketch:
    always_export_binaries: false
updater:
    enable_notification: true

Don't worry about the file now, explanations and updates will happen in due course.

Create a sketch

I prefer to work from my $HOME/workspace/ directory.

mkdir -p ~/workspace/arduino_sketches
cd ~/workspace/arduino_sketches

arduino-cli sketch new hello_world
# Sketch created in: /home/x/workspace/arduino_sketches/hello_world

cat hello_world/hello_world.ino

void setup() {
}

void loop() {
}

Simple code

We'll stick to the example on the documentation for now. Change hello_world.ino to:

void setup() {
    pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(1000);
    digitalWrite(LED_BUILTIN, LOW);
    delay(1000);
}

Update packages:

arduino-cli core update-index

This will download a bunch of files to your hidden .arduino15 folder.

Finding the arduino

After connecting the arduino to your computer:

arduino-cli board list

If you are lucky you will get the board info, otherwise, you might get nothing like I did. You can use this command to find the name of your board and which core to install.

arduino-cli board search

I have an old arduino with an atmega328p microcontroller. Which links to the arduino:avr:uno core. The next step is to download that core:

arduino-cli core install arduino:avr:uno

# Check the core has been installed via:
arduino-cli core list

Note, if you are using 3rd-party cores, you'll need to follow the steps on this documentation: Adding 3rd party cores

Compiling the sketch

Using the info from arduino-cli board search, run this command: Note that my board FQBN is arduino:avr:uno

arduino-cli compile --fqbn arduino:avr:uno hello_world

In my case the command immediately complained I didn't have arduino:avr even though that was not listed in the arduino-cli board search as my FQBN. I installed it nonetheless and then it compiled successfully.

Uploading the sketch

Run this command to find your usb port:

arduino-cli board list

Then run:

arduino-cli upload -p /dev/ttyUSB0 --fqbn arduino:avr:uno hello_world

If you don't have permission to upload to that port, do this:

stat /dev/ttyUSB0

This is the bit that matters:

Gid: (  986/    uucp)

Some people have other value rather than uucp, just change that value in the next command to whatever group your system is using:

sudo usermod -a -G uucp $USER

You'll have to reboot after that. It's important that you do so that the language server part is working properly.

Getting setting up with arduino language server

sudo pacman -S arduino-language-server

Create a sketch.yaml file so that the LSP understands the configuration for the project.

cd ~/workspace/arduino_sketches/hello_world

arduino-cli board attach -p /dev/ttyUSB0 -b arduino:avr:uno hello_world.ino

cat sketch.yaml

default_fqbn: arduino:avr:uno
default_port: /dev/ttyUSB0

The file structure should now look like this:

.
├── hello_world.ino
└── sketch.yaml

That's all, now you can get by with whatever lsp library you use. In my case, I use nvim-lspconfig and my configuration looks like this:

local servers = {'jedi_language_server', 'clangd', 'arduino_language_server'}
for _, lsp in pairs(servers) do
  require('lspconfig')[lsp].setup {
    on_attach = on_attach,
    flags = {
      -- This will be the default in neovim 0.7+
      debounce_text_changes = 150,
    }
  }
end

Adding user commands in neovim

Usage:

:ArduinoCompile
:ArduinoCompileWithUpload
:ArduinoUpload
:ArduinoMonitor

local function arduino_compile(opts)
  local cmd = table.concat({
    "!arduino-cli compile",
    opts.args,
  }, " ")
  vim.cmd(cmd)
end

local function arduino_compile_with_upload(opts)
  local cmd = table.concat({
    "!arduino-cli compile --upload",
    opts.args,
  }, " ")
  vim.cmd(cmd)
end

local function arduino_upload(opts)
  local cmd = table.concat({
    "!arduino-cli upload",
    opts.args,
  }, " ")
  vim.cmd(cmd)
end

vim.api.nvim_create_user_command("ArduinoCompile", arduino_compile, {
  -- Zero or one arguments are accepted
  nargs="?",
  -- Can't be used in visual mode.
  range=false,
})

vim.api.nvim_create_user_command("ArduinoCompileWithUpload", arduino_compile_with_upload, {
  -- Zero or one arguments are accepted
  nargs="?",
  -- Can't be used in visual mode.
  range=false,
})

vim.api.nvim_create_user_command("ArduinoUpload", arduino_upload, {
  -- Zero or one arguments are accepted
  nargs="?",
  -- Can't be used in visual mode.
  range=false,
})