BBC development board containing a NRF51822-QFAA ARM Cortex-M0 processor with 256KB flash and 16KB RAM.

The MCU on this device is now obsolete and so are the `bare metal' development tools.

The most modern platform may be Arduino 1.8.19 which may give an insight as to how to create a modernised SDK.

The nRF51 device and its SDK are now obsolete so hardly viable to develop an application with.

Arduino IDE 1.8.19 supports nRF5 micro-controllers and could be a useful tool to develop applications on the micro:bit and it appears to work.

ZADIG will need to be setup which will install WINUSB on the J-Link debug interface. OpenOCD built into Arduino will then program the micro:bit (slowly).

SEGGER J-Link on board is available for all flavours of the micro:bit to enable a professional debug interface.

Hold down reset and plug board into PC.

Drag J-Link for BBC micro:bit version 1 to MAINTENANCE directory.

Power cycle board and J-Link will become available.

$ /mnt/c/Program\ Files/SEGGER/JLink/JLink.exe
SEGGER J-Link Commander V7.98c (Compiled Aug  7 2024 15:41:14)
DLL version V7.98c, compiled Aug  7 2024 15:40:25

Connecting to J-Link via USB...O.K.
Firmware: J-Link OB-BBC-microbit compiled Nov 16 2022 11:02:58
Hardware version: V1.00
J-Link uptime (since boot): 0d 00h 00m 00s
S/N: 786600064
VTref=3.300V


Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: NRF51822_XXAA
Type '?' for selection dialog
Device>NRF51822_XXAA
Please specify target interface:
  J) JTAG (Default)
  S) SWD
  T) cJTAG
TIF>s
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "NRF51822_XXAA" selected.


Connecting to target via SWD
InitTarget() start
InitTarget() end - Took 12us
Found SW-DP with ID 0x0BB11477
DPIDR: 0x0BB11477
CoreSight SoC-400 or earlier
Scanning AP map to find all available APs
AP[1]: Stopped AP scan as end of AP map has been reached
AP[0]: AHB-AP (IDR: 0x04770021)
Iterating through AP map to find AHB-AP to use
AP[0]: Core found
AP[0]: AHB-AP ROM base: 0xF0000000
CPUID register: 0x410CC200. Implementer code: 0x41 (ARM)
Found Cortex-M0 r0p0, Little endian.
FPUnit: 4 code (BP) slots and 0 literal slots
CoreSight components:
ROMTbl[0] @ F0000000
[0][0]: E00FF000 CID B105100D PID 000BB471 ROM Table
ROMTbl[1] @ E00FF000
[1][0]: E000E000 CID B105E00D PID 000BB008 SCS
[1][1]: E0001000 CID B105E00D PID 000BB00A DWT
[1][2]: E0002000 CID B105E00D PID 000BB00B FPB
[0][1]: F0002000 CID B105900D PID 000BB9A3 ???
SetupTarget() start
SetupTarget() end - Took 746us
Memory zones:
  Zone: "Default" Description: Default access mode
Cortex-M0 identified.
J-Link>

Product homepage

Version 1.5 hardware

Version 1.5 schematic

SEGGER J-Link for micro:bit

Programming resources