Using RTOS with VS Code and PlatformIO

Mbed OS Hello world!
1

I’m on Linux, using VS Code, PlatformIO, and the latest version of mbed. I’ve got basic compilation/uploading working, but I can’t seem to get rtos working.

I need to
#include “rtos/rtos.h”
in order that
ThisThread::sleep_for(500);
is found.

I’m not sure if I’m supposed to include the include line or not. When I try to build, the compilation fails with

undefined reference to `rtos::ThisThread::sleep_for(unsigned long)’

I presume I need to add some kind of configuration option to some json or ini file. What do I need to do?

2

sounds more like a problem with platformIO, current Mbed has rtos included.

3

I think I do have rtos with mbed. It’s a fairly recent version.

I tried adding the following lines to platform.ini

lib_deps = rtos/source

lib_extra_dirs = rtos/source

but it didn’t help. The sources do exist. It just doesn’t seem to want to compile them.

Undoubtedly it’s simple to fix, if only I knew what that something was. As a newbie to all this, there’s so many unfathomable layers of complexity, with build tools, directories and configuration files all over the place.

I did notice some output:

    Library Manager: Installing rtos/source
    Warning! Could not find the package with 'rtos/source' requirements for your system 'linux_x86_64'
    Found 5 compatible libraries

Doesn’t help that much, though.

4

I am using mbed with platformio with no problem. By default it comes with mbed-os 6.2. I do not have lib_deps or lib_extra_dirs in my platformio.ini files.

It looks like you are using the baremetal version of mbed-os to me. What’s the content of the mbed-app.json? (and what do you mean by “latest version of mbed” in the context of platformio? )

Can you compile any of the platformio’s mbed-os example? (especially this one?

David

5

mbed_app.json:

{
"requires": ["bare-metal"],
"target_overrides": {
  "*": {
    "target.c_lib": "small",
    "target.printf_lib": "minimal-printf",
    "platform.minimal-printf-enable-floating-point": false,
    "platform.stdio-minimal-console-only": true
  }
}

}

I’ll try the example you gave shortly.

6

OK … some follow-up. The example you gave compiles successfully.

There’s a couple of caveats:

When I replace platformio.ini with my own board details:

[env:genericSTM32F103C8]
platform = ststm32
board = genericSTM32F103C8
framework = mbed
upload_protocol = stlink

I get the compilation error:

PACKAGES: 
 - framework-mbed 6.51504.200716 (5.15.4) 
 - toolchain-gccarmnoneeabi 1.90201.191206 (9.2.1)
Collecting mbed sources...
mbed build API internal error
Attempt to override undefined parameter 'platform.callback-nontrivial' in 'application[*]'

Also, if I go back to my original project, and edit the file mbed_app.json to remove the “requires” entry, I still get the same compilation error as before. Maybe there’s a stale build environment somehow (??).

Hmm. For a minute there I thought I had cracked it, but it appears not to be.

I guess I don’t actually need threading at this stage. I did spot an interesting async library online which looks interesting if I wanted to go down the concurrency route.

Still, it’s disappointing that mbed’s threading doesn’t seem to build for mcu. It’s difficult to ascertain what the problem is: a configuration problem, board incompatibility, or something else.

7

Ok first: where does this genericSTM32F103C8 board comes from? Where is it defined?

Does it work ok with the NUCLEO_F103RB? (I see no ready-to-use board listed in targets for the F103C8 in mbed 6.5 at least)

(and why do you use MBed 5?)

8

It’s difficult to give answers to some of these questions, as a lot of it was set up automagically by PlatformIO.

I don’t have a NUCLEO_F103RB itself. BUT, looking at mbed online, selecting NUCLEO_F103RB seems to be compatible with the STM32 blue pill (although I don’t know the full extent of compatibility)

I tried mbed online using ThisThread and NUCLEO_F103RB. When I uploaded the binary to my blue pill, it worked as expected.

I’ll tinker around and see if I can cajole PlatformIO to compile on mbed 6. Then I should be able to compile for NUCLEO_F103RB and have it work on the blue pill.

“In theory”.