.. _nucleo_g071rb_board:

ST Nucleo G071RB
################

Overview
********
The Nucleo G071RB board features an ARM Cortex-M0+ based STM32G071RB MCU
with a wide range of connectivity support and configurations. Here are
some highlights of the Nucleo G071RB 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 (LD4), power LED (LD3)
- Two push-buttons: USER and RESET

.. image:: img/nucleo_g071rb.jpg
   :width: 500px
   :height: 367px
   :align: center
   :alt: Nucleo G071RB

More information about the board can be found at the `Nucleo G071RB website`_.

Hardware
********
Nucleo G071RB provides the following hardware components:

- STM32 microcontroller in LQFP64 package
- Two types of extension resources:

  - Arduino* Uno V3 connectivity
  - ST morpho extension pin headers for full access to all STM32 I/Os

- ARM* mbed*
- 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 (3.3V, 5V, 7 - 12V)
  - Power management access point

- Three LEDs:

  - USB communication (LD1), user LED (LD4), power LED (LD3)

- Two push-buttons: USER and RESET
- USB re-enumeration capability. Three different interfaces supported on USB:

  - Virtual COM port
  - Mass storage
  - Debug port

- Support of wide choice of Integrated Development Environments (IDEs) including:

  - IAR
  - ARM Keil
  - GCC-based IDEs

More information about STM32G071RB can be found here:

- `G071RB on www.st.com`_
- `STM32G071 reference manual`_


Supported Features
==================

The Zephyr nucleo_g071rb board configuration supports the following hardware features:

+-----------+------------+-------------------------------------+
| Interface | Controller | Driver/Component                    |
+===========+============+=====================================+
| MPU       | on-chip    | arm memory protection unit          |
+-----------+------------+-------------------------------------+
| NVIC      | on-chip    | nested vector interrupt controller  |
+-----------+------------+-------------------------------------+
| UART      | on-chip    | serial port-polling;                |
|           |            | serial port-interrupt               |
+-----------+------------+-------------------------------------+
| PINMUX    | on-chip    | pinmux                              |
+-----------+------------+-------------------------------------+
| GPIO      | on-chip    | gpio                                |
+-----------+------------+-------------------------------------+
| CLOCK     | on-chip    | reset and clock control             |
+-----------+------------+-------------------------------------+
| WATCHDOG  | on-chip    | independent watchdog                |
+-----------+------------+-------------------------------------+

Other hardware features are not yet supported in this Zephyr port.

The default configuration can be found in the defconfig file:
``boards/arm/nucleo_g071rb/nucleo_g071rb_defconfig``

Connections and IOs
===================

Each of the GPIO pins can be configured by software as output (push-pull or open-drain), as
input (with or without pull-up or pull-down), or as peripheral alternate function. Most of the
GPIO pins are shared with digital or analog alternate functions. All GPIOs are high current
capable except for analog inputs.

Default Zephyr Peripheral Mapping:
----------------------------------

- UART_1 TX/RX : PC4/PC5
- UART_2 TX/RX : PA2/PA3 (ST-Link Virtual Port Com)
- USER_PB   : PC13
- LD4       : PA5

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

Programming and Debugging
*************************

Applications for the ``nucleo_g071rb`` board configuration can be built and
flashed in the usual way (see :ref:`build_an_application` and
:ref:`application_run` for more details).

Flashing
========

Nucleo G071RB board includes an ST-LINK/V2-1 embedded debug tool interface.

This interface is not yet supported by the openocd version included in the Zephyr SDK.

Instead, support can be enabled on pyocd by adding "pack" support with
the following pyocd command:

.. code-block:: console

   $ pyocd pack --install stm32g071rb

Note:
To manually enable the openocd interface, You can still update, compile and install
a 'local' openocd from the official openocd repo http://openocd.zylin.com .
Then run the following openocd command where the '/usr/local/bin/openocd'is your path
for the freshly installed openocd, given by "$ which openocd" :

.. code-block:: console

   $ west flash --openocd /usr/local/bin/openocd

Flashing an application to Nucleo G071RB
----------------------------------------

Here is an example for the :ref:`blinky-sample` application.

.. zephyr-app-commands::
   :zephyr-app: samples/basic/blinky
   :board: nucleo_g071rb
   :goals: build flash

You will see the LED blinking every second.

Debugging
=========

You can debug an application in the usual way.  Here is an example for the
:ref:`hello_world` application.

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: nucleo_g071rb
   :maybe-skip-config:
   :goals: debug

References
**********

.. target-notes::

.. _Nucleo G071RB website:
   http://www.st.com/en/evaluation-tools/nucleo-g071rb.html

.. _STM32G071 reference manual:
   http://www.st.com/resource/en/reference_manual/dm00371828.pdf

.. _STM32 Nucleo-64 board User Manual:
   http://www.st.com/resource/en/user_manual/dm00452640.pdf

.. _G071RB on www.st.com:
   http://www.st.com/en/microcontrollers/stm32g071rb.html
