Illustration: mBlock Bluetooth not connecting? A step-by-step fix for mBot

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Updated 23 October 2026 By Emmanuel SAUVAGE

mBlock Bluetooth not connecting? A step-by-step fix for mBot

mBot, mBot2 or Codey Rocky won't connect over Bluetooth in mBlock? Check in the right order: USB first, mBlock and firmware, PC Bluetooth, pairing, range and interference. Table: USB or Bluetooth for each situation.

Bluetooth between mBlock and a robot (mBot, mBot2, Codey Rocky) is often the first source of frustration: USB works, but wireless refuses. The causes fall into a few families: software, PC radio, pairing and environment. Here is a checking order that avoids mixing everything up.

1. The order to follow (don’t skip steps)

StepCheckWhy
1Prove the robot over USBif a USB upload fails, Bluetooth is not the problem
2Update mBlockuse a version compatible with your OS
3Update the robot’s firmwarean old firmware can block Bluetooth
4PC Bluetoothairplane mode, Fn key, drivers
5Re-pair cleanlyremove the old device, then pair again
6Range and interferencetest at about 1 m first

2. Software and firmware

  • Install mBlock from the official site and read the release notes for your model: see installing mBlock 5.
  • Update the firmware following Makeblock’s documentation for your robot. After a major update, restart both the robot and the PC.

3. Bluetooth on the computer

  • On a laptop, airplane mode or an Fn key can switch the radio off without an obvious warning.
  • Some USB Bluetooth adapters are more stable than the built-in chip: if failures persist, try a recent Bluetooth 5 adapter.

4. Windows pairing

  • Remove the old device in Settings → Bluetooth & devices, then pair again from scratch.
  • Close other apps that might hold the robot (remote-control apps, a second mBlock window).

5. Range and interference

  • Test close to the computer first (about 1 m), with no metal wall in between.
  • Move away USB 3.0 devices, which can disturb some 2.4 GHz links (real but not systematic).

6. USB or Bluetooth?

SituationRecommendation
Classroom, 30 pupilsUSB to upload; Bluetooth for tests if the room allows
Competition or demoUSB, or a setup tested the day before: no first Bluetooth connection on the day
Troubleshootingalways validate over USB before blaming the robot

Our advice: USB first to prove the robot responds; Bluetooth next, with mBlock up to date and a clean pairing. Then build your first mBot program. More guides in Tutorials.

Affiliate link (check current price): USB Bluetooth 5.0 adapter (Amazon US) / Amazon UK.