.. _esp32c3_devkitm:

ESP32-C3
########

Overview
********

ESP32-C3 is a single-core Wi-Fi and Bluetooth 5 (LE) microcontroller SoC,
based on the open-source RISC-V architecture. It strikes the right balance of power,
I/O capabilities and security, thus offering the optimal cost-effective
solution for connected devices.
The availability of Wi-Fi and Bluetooth 5 (LE) connectivity not only makes the device configuration easy,
but it also facilitates a variety of use-cases based on dual connectivity. [1]_

The features include the following:

- 32-bit core RISC-V microcontroller with a maximum clock speed of 160 MHz
- 400 KB of internal RAM
- 802.11b/g/n/e/i
- A Bluetooth LE subsystem that supports features of Bluetooth 5 and Bluetooth mesh
- Various peripherals:

  - 12-bit ADC with up to 6 channels
  - TWAI compatible with CAN bus 2.0
  - Temperature sensor
  - 3x SPI
  - 1x I2S
  - 1x I2C
  - 2x UART
  - LED PWM with up to 6 channels

- Cryptographic hardware acceleration (RNG, ECC, RSA, SHA-2, AES)

System requirements
*******************

Prerequisites
-------------

Espressif HAL requires WiFi and Bluetooth binary blobs in order work. Run the command
below to retrieve those files.

.. code-block:: console

   west blobs fetch hal_espressif

.. note::

   It is recommended running the command above after :file:`west update`.

Building & Flashing
-------------------

Build and flash applications as usual (see :ref:`build_an_application` and
:ref:`application_run` for more details).

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: esp32c3_devkitm
   :goals: build

The usual ``flash`` target will work with the ``esp32c3_devkitm`` board
configuration. Here is an example for the :ref:`hello_world`
application.

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: esp32c3_devkitm
   :goals: flash

Open the serial monitor using the following command:

.. code-block:: shell

   west espressif monitor

After the board has automatically reset and booted, you should see the following
message in the monitor:

.. code-block:: console

   ***** Booting Zephyr OS vx.x.x-xxx-gxxxxxxxxxxxx *****
   Hello World! esp32c3_devkitm

Debugging
---------

As with much custom hardware, the ESP32 modules require patches to
OpenOCD that are not upstreamed yet. Espressif maintains their own fork of
the project. The custom OpenOCD can be obtained at `OpenOCD ESP32`_

The Zephyr SDK uses a bundled version of OpenOCD by default. You can overwrite that behavior by adding the
``-DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>``
parameter when building.

Here is an example for building the :ref:`hello_world` application.

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: esp32c3_devkitm
   :goals: build flash
   :gen-args: -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>

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: esp32c3_devkitm
   :goals: debug

References
**********

.. [1] https://www.espressif.com/en/products/socs/esp32-c3
.. _`ESP32C3 Technical Reference Manual`: https://espressif.com/sites/default/files/documentation/esp32-c3_technical_reference_manual_en.pdf
.. _`ESP32C3 Datasheet`: https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf
.. _`OpenOCD ESP32`: https://github.com/espressif/openocd-esp32/releases