ST Nucleo F401RE

Overview

The Nucleo F401RE board features an ARM Cortex-M4 based STM32F401RE MCU with a wide range of connectivity support and configurations Here are some highlights of the Nucleo F401RE board:

  • STM32 microcontroller in QFP64 package
  • Two types of extension resources:
    • Arduino Uno V3 connectivity
    • ST morpho extension pin headers for full access to all STM32 I/Os
  • On-board ST-LINK/V2-1 debugger/programmer with SWD connector
  • Flexible board power supply:
    • USB VBUS or external source(3.3V, 5V, 7 - 12V)
    • Power management access point
  • Three LEDs: USB communication (LD1), user LED (LD2), power LED (LD3)
  • Two push-buttons: USER and RESET
Nucleo F401RE

More information about the board can be found at the Nucleo F401RE website.

Hardware

Nucleo F401RE provides the following hardware components:

  • STM32F401RET6 in LQFP64 package
  • ARM® 32-bit Cortex®-M4 CPU with FPU
  • 84 MHz max CPU frequency
  • VDD from 1.7 V to 3.6 V
  • 512 KB Flash
  • 96 KB SRAM
  • GPIO with external interrupt capability
  • 12-bit ADC with 16 channels
  • RTC
  • Advanced-control Timer
  • General Purpose Timers (7)
  • Watchdog Timers (2)
  • USART/UART (3)
  • I2C (3)
  • SPI (4)
  • SDIO
  • USB 2.0 OTG FS
  • DMA Controller

More information about STM32F401RE can be found here:

Supported Features

The Zephyr nucleo_401re board configuration supports the following hardware features:

Interface Controller Driver/Component
NVIC on-chip nested vector interrupt controller
UART on-chip serial port-polling; serial port-interrupt
PINMUX on-chip pinmux
GPIO on-chip gpio
PWM on-chip pwm
I2C on-chip i2c

Other hardware features are not yet supported on Zephyr porting.

The default configuration can be found in the defconfig file: boards/arm/nucleo_f401re/nucleo_f401re_defconfig

Pin Mapping

Nucleo F401RE Board has 6 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.

Available pins:

Nucleo F401RE Arduino connectors Nucleo F401RE Morpho connectors

For mode details please refer to STM32 Nucleo-64 board User Manual.

Default Zephyr Peripheral Mapping:

  • UART_1_TX : PB6
  • UART_1_RX : PB7
  • UART_2_TX : PA2
  • UART_2_RX : PA3
  • PWM_2_CH1 : PA0
  • USER_PB : PC13
  • LD2 : PA5

System Clock

Nucleo F401RE 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 84MHz, driven by 8MHz high speed external clock.

Serial Port

Nucleo F401RE board has 3 UARTs. The Zephyr console output is assigned to UART2. Default settings are 115200 8N1.

I2C

Nucleo F401RE board has up to 3 I2Cs. The default I2C mapping for Zephyr is:

  • I2C1_SCL : PB8
  • I2C1_SDA : PB9

Programming and Debugging

Applications for the nucleo_f401re board configuration can be built and flashed in the usual way (see Build an Application and Run an Application for more details).

Flashing

Nucleo F401RE board includes an ST-LINK/V2-1 embedded debug tool interface. This interface is supported by the openocd version included in Zephyr SDK.

Flashing an application to Nucleo F401RE

Connect the Nucleo F401RE to your host computer using the USB port, then run a serial host program to connect with your Nucleo board:

$ minicom -D /dev/ttyACM0

Now build and flash an application. Here is an example for Hello World.

# On Linux/macOS
cd $ZEPHYR_BASE/samples/hello_world
mkdir build && cd build

# On Windows
cd %ZEPHYR_BASE%\samples\hello_world
mkdir build & cd build

# Use cmake to configure a Ninja-based build system:
cmake -GNinja -DBOARD=nucleo_f401re ..

# Now run ninja on the generated build system:
ninja
ninja flash

You should see the following message on the console:

Hello World! arm

Debugging

You can debug an application in the usual way. Here is an example for the Hello World application.

# On Linux/macOS
cd $ZEPHYR_BASE/samples/hello_world
# If you already made a build directory (build) and ran cmake, just 'cd build' instead.
mkdir build && cd build

# On Windows
cd %ZEPHYR_BASE%\samples\hello_world
# If you already made a build directory (build) and ran cmake, just 'cd build' instead.
mkdir build & cd build

# Use cmake to configure a Ninja-based build system:
cmake -GNinja -DBOARD=nucleo_f401re ..

# Now run ninja on the generated build system:
ninja debug