Prime Hub stays off when connected to Android by USB

[BertLindeman]

When connecting a Prime Hub to an Android device by USB, the hub may stay completely off and show no response.

Symptoms:

• The hub does not light up when connected by USB.
• Holding the Bluetooth button while connecting USB does not enter bootloader mode.
• The Pybricks firmware installer cannot detect the hub.
• Android USB options may be unavailable or disabled.

Cause:

On some Samsung Android devices, the Automatic Blocker security setting can block USB connections.
When this is active, the Android device does not provide a usable USB connection to the hub.

Fix:

1. Open:
   Settings -> Security and privacy -> Automatic Blocker
2. Disable Automatic Blocker.
3. Restart the Android device.
4. Connect the Prime Hub again.

After disabling Automatic Blocker:

• USB options become available.
• The Prime Hub can enter bootloader mode.
• The Pybricks firmware installer can detect the hub.

Related info:

This issue affects both Pybricks firmware update methods:

• Older method:

  • Hub off + hold Bluetooth button while connecting USB.

• New since V4.1.0b2:

  • Hub on + connect USB.

The same is applicable to the EV3 hub.

[laurensvalk]

Good to know, thanks Bert!