Knowledge Base.

Cubelets Purchased Before April 2016

You are here:

We have made some major updates on Cubelets robot blocks over the years! Software updates, as well as overhauls to the hardware in Battery Cubelets and changes in our apps, means that some older Cubelets are incompatible with new Cubelets running OS 4.3. Cubelets purchased before April of 2016 may be running OS 3 and cannot be updated at this time.

I don’t know how old my Cubelets are. How do I know if they are running OS 4.3 or not?

The quickest way you can tell which operating system a Cubelet is running is by checking its LED. Every Cubelet has a green LED on the opposite face of it’s ‘action’ face. Snap the Cubelet together with a powered Battery Cubelet. An OS 4.3 Cubelet will first blink three times before blinking intermittently to show that it is receiving power. If the Cubelet is running a personality swap or a custom code that you created in our apps, then the LED will first blink four times before blinking intermittently.

Classic Cubelets on OS 3 or earlier will not first blink three or four times, but just blink slowly to show that they’re receiving power. They will also blink much slower than a Cubelet running OS 4.3.

By using the Cubelets App on a mobile device or Cubelets Console, you can also check any Cubelets operating system by selecting it in the Block Map of the Personality Swap feature.

If your Cubelets were purchased in 2016 or earlier and would like to add to or upgrade your set, please contact us at!

Previous Cubelets Maintenance
Next I’m having trouble with my robots. Who do I contact?
Table of Contents


Frequently asked questions.

Cubelets FAQs is your place to find answers to common questions about Cubelets robot blocks, orders, and Modular Robotics.

Contact us.

Need help, can't find an answer? Contact the Modular Robotics support team and we'll help you!

Shipping and tax policies.

Get the details on Modular Robotics shipping policies and sales tax collection for orders in the United States and around the world.

Warranty and returns.

Cubelets are backed by a one year warranty. Need to make a claim, get a replacement, or have questions? Click to get started.

Cubelets Resources.

Everything you need to teach with Cubelets robot blocks.

Explore a huge collection of K-12 lessons, activities, guides, training, and more.

New to Cubelets?

Learn everything you need to know to start creating more with Cubelets robot blocks in this handy Getting Started Guide.

Go further with Cubelets apps.

Go beyond the building blocks and play with the code inside. Cubelets apps make it easy to create even more with your Cubelets.

Looking for some inspiration?

There are millions of robots you can create with Cubelets. Check out these robots to help inspire your inventions.

Shop Cubelets.


Cubelets robot blocks are used by educators all around the world to help students explore computational thinking, coding, and STEM. 

Jump to...

At Home.

Bring home the educational teaching tool loved by teachers everywhere. Explore sets designed for learning through play.

Jump to...