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Guide to the Bluetooth Hat

The Bluetooth Hat is the newest Cubelets component! Cap your robot constructions with the Bluetooth Hat to quickly and easily pair with any Bluetooth-enabled wireless device using Bluetooth Low Energy (BLE).

Use the Bluetooth Hat with the Cubelets App to Remote Control your robot creations, or change your robot block’s programming with the push of a button using Personality Swap. Want more programming power? Write your own Cubelets code using the Bluetooth Hat and Cubelets Blockly!

In this guide, we’ll go over:

1. Pairing the Bluetooth Hat to your Device
2. Bluetooth Hat LED Color Meanings
3. Bluetooth Hat and Cubelets App Compatibility

Having trouble pairing your Bluetooth Hat or Bluetooth Cubelet to your device? Check out our Bluetooth Troubleshooting Tips for Home and In the Classroom or contact us at!

1. Pairing the Bluetooth Hat to your Device

Pairing the Bluetooth Hat to your device is super simple with Bluetooth Low Energy (BLE). There’s no need to open up your device’s Bluetooth Setting to pair, just make sure your devices Bluetooth is enabled and open up the Cubelets App. Attach the Bluetooth Hat to your powered Cubelets construction and hold the construction near your device for easy location-based pairing.

You can place your Bluetooth Hat anywhere on your Cubelets construction, but it’s a good idea to snap the Hat onto the Battery Cubelet to avoid disconnection while adding or swapping out blocks in your robot construction. If the Bluetooth Hat gets disconnected during robot building, reattach the Hat to the powered robot construction and pairing will happen automatically.

Please note, in all versions of Android OS since Android Marshmallow (6.0),  Location Services permissions are required to successfully scan for nearby Bluetooth LE devices. Modular Robotics will never view, collect, or use your device location even if you agree to these permissions.

2. Bluetooth Hat LED Color Meanings 

You’ll notice a bright multi-colored LED on the Bluetooth Hat which lets you know whether the Hat has paired successfully and helps in troubleshooting.

Blinking Green = The Bluetooth Hat is searching for a device to pair with but is not yet connected.

BTH Green Blink

Blinking Blue = The Bluetooth Hat has successfully paired to a device.

BTH Blink Blue

Upon startup, the Bluetooth Hat will blink a 3 color sequence. This color sequence is used when pairing to Cubelets Blockly and to help tell Bluetooth Hats apart where multiple Hats are in use. There’s no need to pair the Bluetooth Hat in the Bluetooth Settings of your device when using the Cubelets App, but once your Hat is successfully paired it will pop up in your Bluetooth Settings as “Cubelet-XXX” with a unique 3 letter color sequence.

R – Red, Y – Yellow, G – Green, B – Blue, C – Cyan, M – Magenta, W -White

BTH 3 Color MRY Blink

3. Using the Bluetooth Hat with the Cubelets App and Cubelets Blockly

The Bluetooth Hat pairs with your device to connect to the Cubelets App for Remote Control and Personality Swap, as well as Cubelets Blockly for drag-and-drop programming.

If you liked the Bluetooth Hat Pairing video found above, don’t miss our YouTube Tutorials on the Remote Control and Personality Swap features in the Cubelets App and Getting Started with Cubelets Blockly.

FINAL Cubelet App Hardware Universe

The Bluetooth Hat is not able to pair to Cubelets Flash or the Cubelets Updater applications at this time. These legacy applications can only be accessed with the Bluetooth Cubelet.

If you own a Bluetooth Hat and are interested in programming your Cubelets in C with Cubelets Flash, or if you purchased Cubelets before April 2015 and need a Bluetooth Cubelet to update to the OS 4 platform, please contact


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