Affordable and flexible platform to ease prototyping using a STM32L432KCU6 microcontroller.


The STM32 Nucleo board provides an affordable and flexible way for users to try out new ideas and build prototypes with any STM32 microcontroller line, choosing from the various combinations of performance, power consumption and features.

The Arduino™ connectivity support and ST Morpho headers make it easy to expand the functionality of the STM32 Nucleo open development platform with a wide choice of specialized shields.

The STM32 Nucleo board does not require any separate probe as it integrates the ST-LINK/V2-1 debugger/programmer.

Microcontroller features

  • STM32L432KC in UFQFPN32 package
  • ARM®32-bit Cortex®-M4 CPU
  • 80 MHz max CPU frequency
  • VDD from 1.65 V to 3.6 V
  • 256 KB Flash
  • 64 KB SRAM
  • Timers General Purpose (4)
  • SPI/I2S (2)
  • I2C (2)
  • USART (2)
  • 12-bit ADC with 10 channels (1)
  • GPIO (20) with external interrupt capability
  • RTC
  • Random Generator (TRNG for HW entropy)

Nucleo features

  • Two types of extension resources
    • Arduino Uno Revision 3 connectivity
    • STMicroelectronics Morpho extension pin headers for full access to all STM32 I/Os
  • On-board ST-LINK/V2-1 debugger/programmer with SWD connector
    • Selection-mode switch to use the kit as a standalone ST-LINK/V2-1
  • Flexible board power supply
    • USB VBUS or external source (3.3 V, 5 V, 7 - 12 V)
    • Power management access point
  • User LED (LD3)
  • One push button: RESET
  • USB re-enumeration capability: three different interfaces supported on USB
    • Virtual Com port
    • Mass storage (USB Disk drive) for drag'n'drop programming
    • Debug port

Board pinout

Pins Legend


You can find more details on the available pins and labels in the PeripheralPins.c and PinNames.h files.

These files can be found in:

  • ARMmbed/mbed-os repository on GitHub (up-to-date version, used with mbed CLI commands)

  • mbed-dev library in (source files of the mbed library used on mbed compiler IDE)

Arduino-Nano-compatible headers



By default the PA_5 (A4) and PA_6 (A5) pins can only be used as Input floating (ADC function). Remove SB16 and SB18 solder bridges in order to use these pins as Digital output and have access to other functions (DigitalOut, SPI, PWM, etc...). Refer to the user manual for more details.

Supported Shields

Gravitech 7 Segment Display for Arduino Nano

Technical references

For more information, please refer to:

Known limitations

The following section describes known limitations of the platform. Note that general issues are tracked into the mbed repository available on GitHub.


  • Starting from MBED-OS version 5.6.2 (= mbed2 rev 153), you need to update the ST-Link FW to version V2J29M18 (or above) in order to boot (see HERE for more details)

Tips and Tricks

Find more information in ST WIKI pages.

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