PlatformIO Community

ARM Mbed OS 5.11, new builder with support for mbed_app.json


We’re happy to announce support for the latest releases of ARM mbed 5.11 and to introduce a new off-line builder with support for configuration system based on official “mbed_app.json” and build profiles.


What is new



Please open PIO Home and navigate to “Platforms > Updates”

PIO Plus Team


very much increased the size of the firmware (((

#include <mbed.h>
int main() {
DigitalOut led (PC_13);
while(1) {
wait_ms (100);
wait_ms (100);
Building .pioenvs/genericSTM32F103C8/firmware.bin
Memory Usage ->
DATA: [== ] 17.7% (used 3616 bytes from 20480 bytes)
PROGRAM: [===== ] 50.9% (used 33380 bytes from 65536 bytes)


not created a project for bluepill_f103c8_128k

PIO Core Call Error: “The next files/directories have been created in /home/asus/Documents/PlatformIO/Projects/name\ninclude - Put project header files here\nlib - Put here project specific (private) libraries\nsrc - Put project source files here\nplatformio.ini - Project Configuration File\n\nError: Processing bluepill_f103c8_128k (platform: ststm32; board: bluepill_f103c8_128k; framework: mbed)\n--------------------------------------------------------------------------------\nVerbose mode can be enabled via -v, --verbose option\nCONFIGURATION:\nPLATFORM: ST STM32 > BluePill F103C8 (128k)\nHARDWARE: STM32F103C8T6 72MHz 20KB RAM (128KB Flash)\nDEBUG: CURRENT(stlink) EXTERNAL(blackmagic, jlink, stlink)\nwrite() takes exactly 2 arguments (3 given)\nmbed build API internal error\n========================== [ERROR] Took 0.71 seconds ==========================”


Please file an issue here


Nice to know that mbed_apps.json now is supporter, good job.
However I got some regressions after upgrading: mbed_trace.h includes files not found anymore… even if they are there were they are supposed to be.
I thought that I had to do some mods on mbed_apps.json file, I followed the instructions given here but no luck… i got even worst since the parameter “mbed-trace.enable” is not recognised…

Same for FATFileSystem.h… not found anymore, even if feature storage is added

Any chances to get back to the previous version?


Hi @danielm! Thanks for the info. Temporarily, you can fix the platform version in your platformio.ini:

platform = ststm32@~4.6.0

Can you please elaborate on your project settings? I suspect that you don’t use OS in your project? Have you tried to compile your project using the mbed online compiler?


Any news on that? I’m stuck on ststm32 v 4.6.0, and the latest is 5.1 …


You need to enable OS functionality in your project, just add the next line to your platformio.ini