Hammerspoon: Switch layout when USB keyboard is plugged in

init.lua

local usbLogger = hs.logger.new('usb', 'debug')

function configureKeyboard(data)
  -- Uncomment the "usbLogger" line below, plug in the USB keyboard and update the USB vendor and product ID
  local isKeyboardAffected = data.vendorID == 9610 and data.productID == 89
  -- usbLogger.df("eventType %s, pname %s, vname %s, vId %s, pId %s, keyboardAffected %s", data.eventType, data.productName, data.vendorName, data.vendorID, data.productID, isKeyboardAffected)
  if isKeyboardAffected and data.eventType == "added" then
    hs.keycodes.setLayout("U.S.")
  end
  if isKeyboardAffected and data.eventType == "removed" then
    hs.keycodes.setLayout("German")
  end
end

local keyboardWatcher = hs.usb.watcher.new(configureKeyboard)
keyboardWatcher:start()