Nucleo U031R8
Overview
The Nucleo U031R8 board, featuring an ARM Cortex-M0+ based STM32U031R8 MCU, provides an affordable and flexible way for users to try out new concepts and build prototypes by choosing from the various combinations of performance and power consumption features. Here are some highlights of the Nucleo U031R8 board:
STM32U031R8 microcontroller in LQFP48 package
Two types of extension resources:
Arduino Uno V3 connectivity
ST morpho extension pin headers for full access to all STM32U0 I/Os
On-board STLINK-V2EC debugger/programmer with USB re-enumeration capability: mass storage, Virtual COM port, and debug port
Flexible board power supply:
USB VBUS or external source(3.3V, 5V, 7 - 12V)
User LED shared with ARDUINO® Uno V3
Two push-buttons: USER and RESET
USB Type-C® connector for the ST-LINK
More information about the board can be found at the NUCLEO_U031R8 website.
Hardware
The STM32U031x4/6/8 devices are an ultra-low-power microcontrollers family (STM32U0 Series) based on the high-performance Arm® Cortex®-M0+ 32-bit RISC core. They operate at a frequency of up to 56 MHz.
Includes ST state-of-the-art patented technology
Ultra-low-power with FlexPowerControl:
1.71 V to 3.6 V power supply
-40 °C to +85/125 °C temperature range
130 nA VBAT mode: supply for RTC, 9 x 32-bit backup registers
16 nA Shutdown mode (4 wake-up pins)
30 nA Standby mode (6 wake-up pins) without RTC
160 nA Standby mode with RTC
630 nA Stop 2 mode with RTC
515 nA Stop 2 mode without RTC
4 µA wake-up from Stop mode
52 µA/MHz Run mode
Brownout reset
Core:
32-bit Arm® Cortex®-M0+ CPU, frequency up to 56 MHz
ART Accelerator:
1-Kbyte instruction cache allowing 0-wait-state execution from flash memory
Benchmarks:
1.13 DMIPS/MHz (Drystone 2.1)
134 CoreMark® (2.4 CoreMark/MHz at 56 MHz)
430 ULPMark™-CP
167 ULPMark™-PP
20.3 ULPMark™-CM
Memories:
64-Kbyte single bank flash memory, proprietary code readout protection
12-Kbyte SRAM with hardware parity check
General-purpose input/outputs:
Up to 53 fast I/Os, most of them 5 V‑tolerant
Clock management:
4 to 48 MHz crystal oscillator
32 kHz crystal oscillator for RTC (LSE)
Internal 16 MHz factory-trimmed RC (±1%)
Internal low-power 32 kHz RC (±5%)
Internal multispeed 100 kHz to 48 MHz oscillator, auto-trimmed by LSE (better than ±0.25 % accuracy)
PLL for system clock, ADC
Security:
Customer code protection
Robust read out protection (RDP): 3 protection level states and password-based regression (128-bit PSWD)
Hardware protection feature (HDP)
Secure boot
True random number generation, candidate for NIST SP 800-90B certification
Candidate for Arm® PSA level 1 and SESIP level 3 certifications
5 passive anti-tamper pins
96-bit unique ID
Up to 9 timers, RTC, and 2 watchdogs :
1x 16-bit advanced motor-control, 1x 32-bit and 3x 16-bit general purpose, 2x 16-bit basic, 2x low-power 16-bit timers (available in Stop mode), 2x watchdogs, SysTick timer
RTC with hardware calendar, alarms and calibration
Up to 16 communication peripherals:
6x USARTs/LPUARTs (SPI, ISO 7816, LIN, IrDA, modem)
3x I2C interfaces supporting Fast-mode and Fast-mode Plus (up to 1 Mbit/s)
2x SPIs, plus 4x USARTs in SPI mode
IRTIM (Infrared interface)
Rich analog peripherals (independent supply):
1x 12-bit ADC (0.4 µs conversion time), up to 16-bit with hardware oversampling
1x 12-bit DAC output channel, low-power sample and hold
1x general-purpose operational amplifier with built-in PGA (variable gain up to 16)
1x ultra-low-power comparator
ECOPACK2 compliant packages
More information about STM32U031R8 can be found here:
Supported Features
The nucleo_u031r8 board supports the hardware features listed below.
- on-chip / on-board
- Feature integrated in the SoC / present on the board.
- 2 / 2
-
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files. -
vnd,foo -
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.
nucleo_u031r8/stm32u031xx target
Type |
Location |
Description |
Compatible |
|---|---|---|---|
CPU |
on-chip |
ARM Cortex-M0+ CPU1 |
|
ADC |
on-chip |
STM32 ADC1 |
|
Clock control |
on-chip |
STM32F0/G0 RCC (Reset and Clock controller)1 |
|
on-chip |
STM32 HSE Clock1 |
||
on-chip |
|||
on-chip |
STM32 MSI Clock1 |
||
on-chip |
STM32 LSE Clock1 |
||
on-chip |
STM32U0 Main PLL1 |
||
Counter |
on-chip |
STM32 counters5 |
|
Cryptographic accelerator |
on-chip |
STM32 AES Accelerator1 |
|
DAC |
on-chip |
STM32 family DAC1 |
|
DMA |
on-chip |
STM32 DMA controller (V2)1 |
|
on-chip |
STM32 DMAMUX controller1 |
||
Flash controller |
on-chip |
STM32 Family flash controller1 |
|
GPIO & Headers |
on-chip |
STM32 GPIO Controller6 |
|
on-board |
GPIO pins exposed on Arduino Uno (R3) headers1 |
||
I2C |
on-chip |
||
Input |
on-board |
Group of GPIO-bound input keys1 |
|
Interrupt controller |
on-chip |
ARMv6-M NVIC (Nested Vectored Interrupt Controller) controller1 |
|
on-chip |
STM32G0 External Interrupt Controller1 |
||
LED |
on-board |
Group of GPIO-controlled LEDs1 |
|
MTD |
on-chip |
STM32 flash memory1 |
|
Pin control |
on-chip |
STM32 Pin controller1 |
|
PWM |
on-chip |
||
Reset controller |
on-chip |
STM32 Reset and Clock Control (RCC) Controller1 |
|
RNG |
on-chip |
STM32 Random Number Generator1 |
|
RTC |
on-chip |
STM32 RTC1 |
|
Serial controller |
on-chip |
||
on-chip |
STM32 LPUART2 |
||
SPI |
on-chip |
STM32 SPI controller with embedded Rx and Tx FIFOs3 |
|
Timer |
on-chip |
ARMv6-M System Tick1 |
|
on-chip |
|||
on-chip |
STM32 low-power timer (LPTIM)2 |
||
Watchdog |
on-chip |
STM32 watchdog1 |
|
on-chip |
STM32 system window watchdog1 |
Connections and IOs
Nucleo U031R8 Board has 10 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.
For more details please refer to STM32U031 User Manual.
Default Zephyr Peripheral Mapping:
DAC1_OUT1 : PA4
LD1 : PA5
UART_1_TX : PA9
UART_1_RX : PA10
UART_2_TX : PA2
UART_2_RX : PA3
USER_PB : PC13
System Clock
Nucleo U031R8 System Clock could be driven by internal or external oscillator, as well as main PLL clock. By default System clock is driven by PLL clock at 48MHz, driven by 4MHz medium speed internal oscillator.
Serial Port
Nucleo U031R8 board has 4 U(S)ARTs. The Zephyr console output is assigned to USART2. Default settings are 115200 8N1.
Programming and Debugging
Nucleo U031R8 board includes an ST-LINK/V3 embedded debug tool interface. This probe allows to flash the board using various tools.
Flashing
The board is configured to be flashed using west STM32CubeProgrammer runner, so its installation is required.
Alternatively, JLink or pyOCD can also be used to flash the board using
the --runner (or -r) option:
$ west flash --runner pyocd
$ west flash --runner jlink
For pyOCD, additional target information needs to be installed by executing the following pyOCD commands:
$ pyocd pack --update
$ pyocd pack --install stm32u0
Flashing an application to Nucleo U031R8
Connect the Nucleo U031R8 to your host computer using the USB port. Then build and flash an application. Here is an example for the Hello World application.
Run a serial host program to connect with your Nucleo board:
$ minicom -D /dev/ttyACM0
Then build and flash the application.
# From the root of the zephyr repository
west build -b nucleo_u031r8 samples/hello_world
west flash
You should see the following message on the console:
Hello World! nucleo_u031r8
Debugging
Default flasher for this board is openocd. It could be used in the usual way. Here is an example for the Blinky application.
# From the root of the zephyr repository
west build -b nucleo_u031r8 samples/basic/blinky
west debug
Note: Check the build/tfm directory to ensure that the commands required by these scripts
(readlink, etc.) are available on your system. Please also check STM32_Programmer_CLI
(which is used for initialization) is available in the PATH.