node eg/led-PCA9685.js

const { Board, Led } = require("johnny-five");
const board = new Board();

board.on("ready", () => {
  const led = new Led({
    pin: process.argv[2] || 0,
    address: 0x40,
    controller: "PCA9685"
  });

  // address: The address of the shield.
  //    Defaults to 0x40
  // pin: The pin the LED is connected to
  //    Defaults to 0
  // controller: The type of controller being used.
  //   Defaults to "standard".

  // Add LED to REPL (optional)
  board.repl.inject({ led });

  led.pulse();
});