FFXIV fishing controlled by a Playdate.

The Playdate is a handheld game console with a crank. A friend gave me the idea to connect the crank to FFXIV fishing. Here it is.

The Playdate exposes a serial connection over USB. There are two features on the serial connection we can (ab)use:

• Anything you print in a game gets logged to the serial port
• You can evaluate Lua bytecode with the eval command

Note the bytecode in that sentence. We can evaluate custom Lua on the fly, but compiling a new program for each command sounds miserable. However, I have too much experience with Lua bytecode, and I found this excellent GitHub gist that details splicing data into Lua bytecode to pass JSON to the game. I reimplemented that gist in C#, allowing me to have two way communication with everyone's favorite cheese slice.

This guide assumes you are a developer that is probably in the Playdate developer ecosystem but is probably not in the FFXIV developer ecosystem. You will have to build this from source - I'm not providing binaries for a project this dumb.

Requirements:

• A Playdate and XIVLauncher
• The Playdate SDK and .NET 7 SDK

First, build and install the Playdate game (making sure you have the Playdate SDK in your path, and your Playdate is connected via USB and is unlocked):

pdc ./playdate ./com.notnite.playdatefishing.pdx
pdutil install ./com.notnite.playdatefishing.pdx

Then, build the Dalamud plugin:

dotnet build ./dalamud/PlaydateFishing

Now, open FFXIV. Go into the Experimental tab of the Dalamud settings (/xlsettings), and add the path to the built DLL to the "Dev Plugin Locations" section. Then, do the following:

• Plug in your Playdate to your computer
• Ensure your Playdate is unlocked on the home screen
• Enable the Dalamud plugin, then start the Playdate game, in that exact order

Congrats - you can now rethink your life choices. It is suggested to disable the plugin before closing the game.

• Undock the crank to use Cast
• Dock the crank to use Quit
• Crank to use Hook
  • If you use Patience, the speed you crank at determines whether to use Precision Hookset or Powerful Hookset

First, don't.

Second, I work on the Playdate part in Visual Studio Code and the FFXIV part in JetBrains Rider. If you're contributing to the Lua part, consider making a .vscode/settings.json like the following, to silence some annoying errors:

{
  "Lua.workspace.library": [
    "<path to your playdate SDK>/CoreLibs",
    "playdate/annotations.lua"
  ],
  "Lua.diagnostics.globals": [
    "playdate",
    "fishing",
    "input",
    "log",
    "json"
  ],
  "Lua.runtime.special": {
    "import": "require"
  }
}