Updating your micro:bit firmware

What is the micro:bit firmware?

Firmware is a special kind of software that makes devices function properly. You can think of it as the software that makes a machine behave the way it does. The micro:bit has two chips on the back of it; one of them runs your code, while the other one runs the firmware to enable you to program the device.

The micro:bit will work with the firmware it came with, so if you don't need to update it head back to our guide to the micro:bit features.

There may be times when you may want to update the firmware to test out new software features. If that's the case, this page will show you how to do it.

How to find out the current firmware version

Before you upgrade, you'll want to find out what version of the firmware you have on your micro:bit. Plug it in via USB, open up the DETAILS.TXT file from the MICROBIT drive and look for the number on the line that begins 'Interface Version'.

# DAPLink Firmware - see https://mbed.com/daplink Unique ID: 9900000031634e4500624014000000320000000097969901
HIC ID: 97969901
Auto Reset: 1
Automation allowed: 0
Overflow detection: 0
Daplink Mode: Interface
Interface Version: 0250
Git SHA: 682d8303e37355532402b8d93c4f240a3cec02a9
Local Mods: 0
USB Interfaces: MSD, CDC, HID, WebUSB
Interface CRC: 0x3f2b7e12
Remount count: 0
URL: https://microbit.org/device/?id=9900&v=0250

How to update the firmware

  1. Download the hex file from this page to your computer.
  2. Download the latest micro:bit firmware
  3. Then with the battery pack removed and a USB lead connected to your computer, hold the reset button at the back of the micro:bit and plug the USB lead into the device. You should see a drive appear in your file manager called MAINTENANCE.
  4. Maintenance mode on a micro:bit
  5. Drag and drop the .HEX you downloaded from this page onto the micro:bit and wait for the yellow system LED on the back of the device to stop flashing. When the upgrade is completed, the micro:bit will reset, ejecting itself from the computer and re-appear in normal MICROBIT drive mode.
  6. Finally, check the DETAILS.TXT file that is on the MICROBIT drive and make sure that it has the same version number as the .HEX firmware that you just downloaded and flashed to the interface chip.
  7. Previous firmware versions

    Should you wish to roll back the firmware for any reason, you can download a previous version here.

    version 0241 version 0250
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