The highly affordable STM32 Nucleo development boards allow to try out new ideas and to quickly create prototypes with any STM32 MCU.
Sharing connectors, STM32 Nucleo boards can easily be extended with a large number of application related hardware add-ons (Nucleo-64 include Arduino Uno rev3 & ST morpho connectors, Nucleo-32 include Arduino Nano connectors).
The STM32 Nucleo boards integrate an ST-Link debugger/programmer, so there is no need for a separate probe.
A comprehensive STM32 software HAL library together with various software examples are provided with the STM32 Nucleo development boards, and seamlessly work with a wide range of development environments including IAR EWARM, Keil MDK-ARM, mbed and GCC/LLVM-based IDEs.
All STM32 Nucleo users have free access to the mbed online resources (compiler, C/C++ SDK, and developer community) at www.mbed.org allowing to build a complete application in only a few minutes.