Help & Support

When the micro:bit is plugged in via a USB cable it will show up as a disk drive called MICROBIT.  One of the files on the drive will be called DETAILS.TXT and this file contains information about the firmware running on the board. It is the job of this firmware to enable the USB connection and present the drive on a computer.

This article describes the purpose of each line in the DETAILS.TXT file when the board is in MICROBIT mode. If the board is in MAINTENANCE mode, the DETAILS.TXT will have different 'bootloader' settings that are pre-configured by DAPLink.

A typical DETAILS.TXT file might look like this:

# DAPLink Firmware - see https://mbed.com/daplink

Unique ID: 9904360258434e45003e400e00000059000000009796990b 

HIC ID: 9796990b

Auto Reset: 1

Automation allowed: 0

Overflow detection: 0

Incompatible image detection: 1

Page erasing: 0

Daplink Mode: Interface

Interface Version: 0255

Bootloader Version: 0255

Git SHA: 1436bdcc67029fdfc0ff03b73e12045bb6a9f272

Local Mods: 0

USB Interfaces: MSD, CDC, HID, WebUSB

Bootloader CRC: 0x828c6069

Interface CRC: 0x5b5cc0f5

Remount count: 0

URL: https://microbit.org/device/?id=9904&v=0255

Unique ID

The first four digits represent the Vendor and Device, so `99` is for micro:bit and `04` for the V2 device. A V1 device will have an ID of `00` or `01`

The following 24 characters `58434e45003e400e00000059` is unique to your device and the last 16 characters contain further information about the board including the HIC ID

HIC ID

This identifies the family of DAPLink firmware interface chip. It is part of the Unique ID. 

Auto Reset: 1

Auto Reset is a mode configuration. In this mode, a reset is performed at the end of the programming sequence and the micro:bit starts running the program starts running. `1` indicates that this mode is on and `0` is off. In MICROBIT mode this is set to `0` or off and in MAINTENANCE mode this is set to `1` or on.

Automation allowed: 0

In this mode, a set of firmware DAPLink MSD commands can be triggered without needing to hold down the RESET button. Also, bootloader firmware updates are allowed only in automation-allowed mode. In MICROBIT mode this is set to `0` or off and in MAINTENANCE mode this is set to `1` or on.

Overflow detection: 0

This feature detects if there is an overflow of data in the UART buffer. It is not configured for the micro:bit. By definition, if an overflow were detected data might be dropped entirely from the buffer or new data might not be added.

Incompatible image detection: 1

This mode will ensure an error is displayed on the device if the .hex file that is flashed to it is not in the format required by the DAPLink Mode. For example, if you try to flash a firmware image to the micro:bit when it is not in MAINTENANCE mode

Page erasing: 0

This setting chooses whether to erase all of the flash at once (the default for the micro:bit) or page by page, where it might be useful to not overwrite data in the flash memory.

Daplink Mode: Interface

This mode defines whether the micro:bit is expecting to receive a program or a firmware update. In Interface mode, the device will show up as a drive called MICROBIT to be programmed with a normal .hex file. In Bootloader mode, the device will show up as a drive called MAINTENANCE to be updated with a DAPLink firmware file.

Interface Version: 0255

The version of the firmware that the board is currently running. In special circumstances, such as to enable a new feature, this can be updated by flashing a file from https://microbit.org/get-started/user-guide/firmware/ whilst in MAINTENANCE mode

Bootloader Version: 0255

The version of the Bootloader that the board is currently running. In normal circumstances, you would not need to update this.

Git SHA: 1436bdcc67029fdfc0ff03b73e12045bb6a9f272

The checksum identifies the Git commit for the interface and bootloader version.

Local Mods: 0

This value shows if there have been any local modifications to the DAPLink firmware since the last commit. It will change to 1 if there are any number of local unsaved changes.

USB Interfaces: MSD, CDC, HID, WebUSB

USB interface modes that are available to the micro:bit. Earlier versions of the DAPLink firmware for the V1 micro:bit (pre 0249) did not have WebUSB support.

Bootloader CRC: 0x828c6069

Cyclic Redundancy Check. This is an operation on flash data that checks the validity of the DAPLink bootloader that has been flashed to the board.

Interface CRC: 0x5b5cc0f5

Cyclic Redundancy Check. This is an operation on flash data that checks the validity of the DAPLink interface that has been flashed to the board.

Remount count: 0

Incremental count each time the flash is unsuccessful and a new error is encountered. (The behaviour on the micro:bit is to be confirmed)

URL: https://microbit.org/device/?id=9904&v=0255

A link that contains identifying information for the board ID number and the DAPLink version