Unable to build & debug BBC micro:bit v2 using PlatformIO with Zephyr 2.5.0

Development Platforms
1

The bbcmicrobit_v2 board support for Zephyr is coming up as unrecognized.

PlatformIO Zephyr (and mbed) support for BBC micro:bit v1 (bbcmicrobit) exists but support for micro:bit v2 is currently missing.

Hopefully we’ll have PlatformIO Zephyr support for the updated micro:bit v2 soon.

2

Could you please try the following

  • go into C:\Users\<user>\.platformio\platforms\nordicnrf52\boards\bbcmicrobit_v2.json
  • replace the file fully with the content
{
  "build": {
    "arduino":{
      "ldscript": "nrf52833_xxaa.ld"
    },
    "core": "nRF5",
    "cpu": "cortex-m4",
    "extra_flags": "-DARDUINO_BBC_MICROBIT_V2 -DNRF52833_XXAA",
    "f_cpu": "64000000L",
    "mcu": "nrf52833",
    "variant": "BBCmicrobitV2",
    "zephyr": {
      "variant": "bbc_microbit_v2"
    }
  },
  "connectivity": [
    "bluetooth"
  ],
  "debug": {
    "onboard_tools": [
      "cmsis-dap"
    ],
    "svd_path": "nrf52.svd",
    "openocd_extra_args": [
      "-c",
      "transport select swd;"
    ],
    "jlink_device": "nRF52833_xxAA"
  },
  "frameworks": [
    "arduino",
    "zephyr"
  ],
  "name": "BBC micro:bit V2",
  "upload": {
    "maximum_ram_size": 65536,
    "maximum_size": 524288,
    "protocol": "cmsis-dap",
    "protocols": [
      "jlink",
      "nrfjprog",
      "stlink",
      "blackmagic",
      "cmsis-dap",
      "mbed"
    ]
  },
  "url": "https://microbit.org/new-microbit/",
  "vendor": "BBC"
}
  • try recreating a Zephyr project for the board
1 Like
3

Neat stuff! Thank you.

I added the Zephyr framework support in bbcmicrobit_v2.json, as per your instructions.

I’m now able to upload and run/debug code to the micro:bit v2 using PlatformIO and the Zephyr framework.

I’ve tested a couple of projects in both debug & release. Upload and debug via cmsis-dap (micro:bit v2 default) and jlink (micro:bit v2 flashed with Segger J-Link OB firmware) work fine.

The straight forward changes to add support for the Zephyr framework shows the power of PlatformIO. It’s a pleasure to use PlatformIO!

What is the process to get the changes into the next nRF52 update? Do you want me to notify the appropriate person(s) or group?

4

I’ve just PRed into the repo where the board definition file is (Add Zephyr build info to BBC Microbit V2 by maxgerhardt · Pull Request #107 · platformio/platform-nordicnrf52 · GitHub), if accepted they hopefully do a re-release soon (or one can use the upstream version after the merge to get these changes without local modifications)

5

Linked PR was merged and usable per instructions above; Will automatically be in next release.

6

Great! Good to understand the process.

7

Yesterday, whilst building a bbc_microbit_v2 PlatformIO project, I noticed that the RAM size specified in \Users\<user>\.platformio\platforms\nordicnrf52\boards\bbcmicrobit_v2.json

is incorrect.

Processing microbit (platform: nordicnrf52; board: bbcmicrobit_v2; framework: zephyr)
--------------------------------------------------------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/nordicnrf52/bbcmicrobit_v2.html
PLATFORM: Nordic nRF52 (7.0.0) > BBC micro:bit V2
HARDWARE: NRF52833 64MHz, 64KB RAM, 512KB Flash
DEBUG: Current (jlink) On-board (cmsis-dap) External (blackmagic, jlink, stlink)
PACKAGES: 
 - framework-zephyr 2.20500.210226 (2.5.0) 
 - framework-zephyr-canopennode 0.0.0-alpha+sha.468d350028 
 - framework-zephyr-civetweb 0.0.0-alpha+sha.e6903b80c0 
 - framework-zephyr-cmsis 0.0.0-alpha+sha.c3bd2094f9 
..
...
...

The BBC micro:bit v2 has 128K of RAM.

maximum_ram_size in

\Users\<user>\.platformio\platforms\nordicnrf52\boards\bbcmicrobit_v2.json should be set to the following:

"maximum_ram_size": 131,072

I have build and debugged quite a few projects with the board bbcmicrobit_v2. json and I have had no issues.

Please notify the relevant developers to update the json. Thanks.

8

I PRed per Correct RAM size for BBC Micro:Bit v2 by maxgerhardt · Pull Request #108 · platformio/platform-nordicnrf52 · GitHub to have this fixed.

EDIT: PR is merged and can thus be included via the upstream.

9

Thanks for raising the PR.

1 Like