# Makecode Micro:bit Bluetooth APP Problem : Solution
**URL:** https://forum.makecode.com/t/makecode-micro-bit-bluetooth-app-problem-solution/45691
**Category:** micro:bit
**Created:** [September 2, 2026, 9:42pm UTC](https://forum.makecode.com/t/makecode-micro-bit-bluetooth-app-problem-solution/45691 "2026-09-02T21:42:15Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@frank\_schmidt](https://forum.makecode.com/u/frank_schmidt)
#### Post date: [September 2, 2026, 9:42pm UTC](https://forum.makecode.com/t/makecode-micro-bit-bluetooth-app-problem-solution/45691/1 "2026-09-02T21:42:15Z")
Bluetooth upload of Makecode to BBC Micro:bit (have only tried V2 Micro:bit -MB) the upload fails when there is complex code already installed on the MB. In the classroom this would be frustrating due to time constraints of the class length. Using Android and a Micro:bit which already has code installed via USB from a computer or Chromebook; the APP seems to not be able to uninstall that code in order to install new code via Bluetooth. The entire pairing process is successful using the APP, the next step is said to be uploading code but the vertical LED progress bars on the MB going from left to right are not activated; ie-no upload progression is actually taking place. I find the solution is, before class, erase the complex code on each MB via USB cable and computer in the Makecode environment by uploading a simple "On start, show number “0” " Once this is installed on the MB (complex code having been erased via computer), the APP upload works as expected.
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### Author:  [@martinwork](https://forum.makecode.com/u/martinwork)
#### Post date: [September 6, 2026, 11:43pm UTC](https://forum.makecode.com/t/makecode-micro-bit-bluetooth-app-problem-solution/45691/2 "2026-09-06T23:43:56Z")
Yes, USB transfer of a new MakeCode project is a good idea, if a micro:bit may have been used with unusual programs - e.g. not MakeCode; or not the default “just works” pairing mode.
For a fresh start, drag a new MakeCode project’s hex file to the MICROBIT drive, and delete Bluetooth pairings in the mobile device settings.
All support for Bluetooth pairing, and transfer of a new program, is provided by code in the last program transferred. Some programs don’t have that support. And the mobile device may think it is paired with a previous program.