A family tradition for christmas / end of the year is to build a large Lego set as a team. This year, I surprised everyone with the Lego Disney Train and Station. It is a cool, very detailed set.

Also, the train is powered, and comes with a (new?) Bluetooth controller. You can install an app on your iPhone or Android and then use it to control the train. Basically, speed and direction.

We had a lot of fun for many days building the wholem thing collaboratively. And then I thought: BLE, iPhone app … would it be cool to program that?

A little googling and I found a library for Arduino BLE. I’ve got an awesome Nano33 some time ago, but then I read a little bit more and found an even easier way with Nathan Kellenicki’s awesome nodejs library.

More info on Lego controllers on this post from the same author.

And here’s my modified “hello train”:

const PoweredUP = require("node-poweredup");
const poweredUP = new PoweredUP.PoweredUP();

const { log } = console;

poweredUP.on("discover", async (hub) => { // Wait to discover a Hub
    log(`Discovered ${hub.name}!`);
    await hub.connect(); // Connect to the Hub
    log("Connected");
    
    await hub.sleep(3000); // Sleep for 3 seconds before starting

    log("MAC Address:" + hub.primaryMACAddress);
    log("Firmware: " + hub.firmwareVersion);
    log("Hardware: " + hub.hardwareVersion);

    await hub.setMotorSpeed("A", 50);
});

poweredUP.scan(); // Start scanning for Hubs
console.log("Scanning for Hubs...");

Which opens up an entire world of exciting possibilities.

Lego’s protocol

For those interested in the internals, Lego has open sourced their protocols