ST Nucleo F401RE¶
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
More information about the board can be found at the Nucleo F401RE website.
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
- Advanced-control Timer
- General Purpose Timers (7)
- Watchdog Timers (2)
- USART/UART (3)
- I2C (3)
- SPI (4)
- USB 2.0 OTG FS
- DMA Controller
More information about STM32F401RE can be found here:
The Zephyr nucleo_401re board configuration supports the following hardware features:
|NVIC||on-chip||nested vector interrupt controller|
|UART||on-chip||serial port-polling; serial port-interrupt|
Other hardware features are not yet supported on Zephyr porting.
The default configuration can be found in the defconfig file:
Nucleo F401RE Board has 6 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.
Default Zephyr Peripheral Mapping:¶
- UART_1 TX/RX : PB6/PB7
- UART_2 TX/RX : PA2/PA3 (ST-Link Virtual Port Com)
- I2C1 SCL/SDA : PB8/PB9 (Arduino I2C)
- SPI1 CS/SCK/MISO/MOSI : PA4/PA5/PA6/PA7 (Arduino SPI)
- PWM_2_CH1 : PA0
- USER_PB : PC13
- LD2 : PA5
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.
Nucleo F401RE board has 3 UARTs. The Zephyr console output is assigned to UART2. Default settings are 115200 8N1.
Nucleo F401RE board has up to 3 I2Cs. The default I2C mapping for Zephyr is:
- I2C1_SCL : PB8
- I2C1_SDA : PB9
Programming and Debugging¶
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
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 # If you already made a build directory (build) and ran cmake, just 'cd build' instead. # Use cmake to configure a Ninja-based build system: cmake -GNinja -DBOARD=nucleo_f401re .. # Now run ninja on the generated build system: ninja debug