12 months ago.

nrf52 blinky on mbed - Error compilling original sample...


I would like to give a try to nrf52 on mbed. So I went to:


and clicked Import to compiler

I check the update... check box and the project was imported. The target board is selected on the top right corner ("Nordic nRF52-DK")

When I click Compile | Build only Lots of warnings as displayed but one error is also displayed:

Error: Non-constant-expression cannot be narrowed from type 'int' to 'std::uint8_t' (aka 'unsigned char') in initializer list [-Wc++11-narrowing] in "extras/mbed-os.lib/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NORDIC_SOFTDEVICE/TARGET_NRF52/source/nRF5xGap.cpp", Line: 749, Col: 9

Why is this error appearing with the original source code? How to solve it?

By the way, is mbed using the softdevice from nordic or an alternative one?



1 Answer

12 months ago.

Hi Imo,
I have reproduced the error.
Please update mbed-os form 5.12.1(imported rev.) to 5.13.0(as of today).
You can compile it without an error message but still lots of warnings.
I don't test the program because I'm using the board at another place right now.

Mbed's revision control is always running, and I have never seen a stable bug-free one for the past nine years.
Be careful even the official sample program.
The lack of a stable program is likely to be the cause of the moving to Arduino from Mbed.

Yes, Mbed nRF5x serises use Noridic Softdevice as you expect.
You can confirm it by following readme file (see SoftDevice explanation, near the end of line).

Hello Kenji Arai Thanks it works now!

By the way, are you saying that you have put mbed apart and went to Arduino? I have been using nordic SD and the interrupt oriented way of programming but I think I will feel more confortable with a thread riented operating system hence I decided to move to mbed. But Now I reaized that you have moved from mbed to arduino . Is it true? Can I ask your advice about this issue? In arduino wich libraries do you use to program nrf52 based boards? What about energy consumption? Is arduino libraries energy efficient? thanks a lot!

posted by Imo Co 13 Jul 2019

Hi Imo,
No, I am in the Mbed community !!
I pointed out that even a very simple LED flashing program does not work correctly with Mbed.
This is too bad for those who have started studying Mbed for the first time.
I am concerned that such a person may choose to Arduino.
There is no objection to the big goal of Mbed such as RTOS and IOT connection, but I think that bug-free, stable condition is more important than the new function for the released mbed-os5.
For your several question, please give me a private message and discuss it separately.
Do you know the way to send a private message?

posted by Kenji Arai 13 Jul 2019

No I dont know how to post a private message. The mbed platform seems interesting for me. I have at least 2 questions

posted by Imo Co 13 Jul 2019

Click my name (blue part)
Appear my profile page then click "private message"

posted by Kenji Arai 14 Jul 2019

I have sent already...

posted by Imo Co 14 Jul 2019