Modification of Mbed-dev library for LQFP48 package microcontrollers: STM32F103C8 (STM32F103C8T6) and STM32F103CB (STM32F103CBT6) (Bluepill boards, Maple mini etc. )

Fork of mbed-STM32F103C8_org by Nothing Special

Library for STM32F103C8 (Bluepill boards etc.).
Use this instead of mbed library.
This library allows the size of the code in the FLASH up to 128kB. Therefore, code also runs on microcontrollers STM32F103CB (eg. Maple mini).
But in the case of STM32F103C8, check the size of the resulting code would not exceed 64kB.

To compile a program with this library, use NUCLEO-F103RB as the target name. !


  • Corrected initialization of the HSE + crystal clock (mbed permanent bug), allowing the use of on-board xtal (8MHz).(1)
  • Additionally, it also set USB clock (48Mhz).(2)
  • Definitions of pins and peripherals adjusted to LQFP48 case.
  • Board led LED1 is now PC_13 (3)
  • USER_BUTTON is now PC_14 (4)

    Now the library is complete rebuilt based on mbed-dev v160 (and not yet fully tested).

(1) - In case 8MHz xtal on board, CPU frequency is 72MHz. Without xtal is 64MHz.
(2) - Using the USB interface is only possible if STM32 is clocking by on-board 8MHz xtal or external clock signal 8MHz on the OSC_IN pin.
(3) - On Bluepill board led operation is reversed, i.e. 0 - led on, 1 - led off.
(4) - Bluepill board has no real user button


After export to SW4STM (AC6):

  • add line #include "mbed_config.h" in files Serial.h and RawSerial.h
  • in project properties change Optimisation Level to Optimise for size (-Os)
Download repository: zip gz

Files at revision 148:8b0b02bf146f

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.yotta_ignore 276 Revisions Annotate
mbed.h 2974 Revisions Annotate