Mbed Online Compiler discontinuation, will there be support for mbed board

The Mbed Online Compiler will be switched off at the end of December 2022. I use mbed development board with LPC1768 microcontroller to teach my class. I know this board is not currently supported in Keil Studio. Will it be supported in 2023? Please let me know.


be so kind place your question to correct section. You can do it via the edit (pen icon) what is close to the title of this topic.

I do not know why you think that, but from my point of view there is some misunderstanding.
How I remember the Debug and Run functionality for the LPC1768 is not supported in KSC, this is true. But that does not mean it is not supported for the build. The workflow will be very similar like with Online Compiler now. The output of the Build function is downloaded .bin file in your web browser.

So give it a try and you will see.

BR, Jan

Hello Jan,

Yes, it is true that build works with LPC1768, even I see the message “Hardware not supported”. But many features do not work, like some of libraries written for old compiler or programing LPC1768 peripheral registers, like writing to PCONP. Also, not possible to use debug. Obviously, the board cannot be flashed either. I use all these features for my class, and would like to know if you are planning to write the firmware for LPC1768 and support it in the future.

Thank you



The level of support for the LPC1768 is currently the same as in the Online Compiler (you can build for it and drag-and-drop the binary to program the board). Run and debug have been very difficult to enable for the LPC1768, as the interface firmware is an ancestor of the DAPLink firmware, and so is a unique case. However, we are working on this task.

Could you please link me to the libraries that don’t work as expected? We can investigate. - Edit, we’ve temporarily disabled the code pages (e.g. mercurial repositories) as we have experienced issues with the mercurial version control that manages these pages, but once we re-enable it we will let you know and you can share the libraries you mention.

I am a guy from community, but I believe someone from Keil Studio team give you an answer soon (I see, Joe already did it)
To be honest libraries have nothing to do with migration from Online compiler to KSC, that is related to MbedOS version. When you will update the MbedOS to latest, in the Online compiler, you will faced same Issue.

BR, Jan

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Keil Studio serial terminal cannot be used with LPC1768; I was not able to use any other Serial terminal either. printf( ) function is not supported unless argument is an integer. For example, this library cannot be used:

Yes, build-in Serial terminal is currently supported only for boards what have already updated DAP Link firmware (For example FRDM-K66F I think). I believe this will be supported for more boards in the future. But you can use any other Serial terminal pc app like you use it until now.

The printf function is working normal, but it does not print out any flouts because that is new default settings what can be changed, please look - Minimal printf and snprintf.

The library is currently unavailable because of reported Mercurical issue, however I know this library and how I wrote you above, that is not related to KSC, it is related to MbedOS version.
You probably use an old MbedOS version (definitely older than MbedOS6+), that is why you have problem with everything.

MbedOS versions

  • MbedOS 2 - odest from 2010 and marked as deprecate maybe more than 3 years ago
  • MbedOS 5 - First release in 2016 and latest version is MbedOS 5.15.9
  • MbedOS 6 - First release in 2020 and latest version is MbedOS 6.16

KSC supporting whole MbedOS6+, MbedOS 5.12+ and a version of MbedOS 2, but recommended is latest one, the latest is Mbed OS6.16.

All old libraries were made for MbedOS 2, some of them are working also with MbedOS 5, but most of them are not compatible with MbedOS 6+. Libraries are not in Mbed responsibility, it is community part of job, but people are lazy.

Do you have a list of libraries or already prepered old programs what you use for your class?

BR, Jan

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What about writing to LPC1768 registers? Since some functionalities like sleep modes are not supported by mbed API?


Registers are still accessible, it is one benefit of MbedOS, you can combinate Registers, HALL implementation and MbedOS APIs.

I recommend to to meet with news in latest MbedOS, maybe that is not true anymore, but I do not know I do not use it.

However, for example the LPC_SC->PCONP is accessible, compilable and also intellisense know about it.

BR, Jan