.. zephyr:board:: esp32_devkitc_wrover Overview ******** ESP32 is a series of low cost, low power system on a chip microcontrollers with integrated Wi-Fi & dual-mode Bluetooth. The ESP32 series employs a Tensilica Xtensa LX6 microprocessor in both dual-core and single-core variations. ESP32 is created and developed by Espressif Systems, a Shanghai-based Chinese company, and is manufactured by TSMC using their 40nm process. For more information, check `ESP32-DevKitC-WROVER`_. The features include the following: - Dual core Xtensa microprocessor (LX6), running at 160 or 240MHz - 520KB of SRAM - 802.11b/g/n/e/i - Bluetooth v4.2 BR/EDR and BLE - Various peripherals: - 12-bit ADC with up to 18 channels - 2x 8-bit DACs - 10x touch sensors - Temperature sensor - 4x SPI - 2x I2S - 2x I2C - 3x UART - SD/SDIO/MMC host - Slave (SDIO/SPI) - Ethernet MAC - CAN bus 2.0 - IR (RX/TX) - Motor PWM - LED PWM with up to 16 channels - Hall effect sensor - Cryptographic hardware acceleration (RNG, ECC, RSA, SHA-2, AES) - 5uA deep sleep current For more information, check the datasheet at `ESP32 Datasheet`_ or the technical reference manual at `ESP32 Technical Reference Manual`_. Asymmetric Multiprocessing (AMP) ******************************** ESP32-DevKitC-WROVER allows 2 different applications to be executed in ESP32 SoC. Due to its dual-core architecture, each core can be enabled to execute customized tasks in stand-alone mode and/or exchanging data over OpenAMP framework. See :zephyr:code-sample-category:`ipc` folder as code reference. Supported Features ================== Current Zephyr's ESP32-DevKitC-WROVER board supports the following features: +------------+------------+-------------------------------------+ | Interface | Controller | Driver/Component | +============+============+=====================================+ | UART | on-chip | serial port | +------------+------------+-------------------------------------+ | GPIO | on-chip | gpio | +------------+------------+-------------------------------------+ | PINMUX | on-chip | pinmux | +------------+------------+-------------------------------------+ | USB-JTAG | on-chip | hardware interface | +------------+------------+-------------------------------------+ | SPI Master | on-chip | spi | +------------+------------+-------------------------------------+ | Timers | on-chip | counter | +------------+------------+-------------------------------------+ | Watchdog | on-chip | watchdog | +------------+------------+-------------------------------------+ | TRNG | on-chip | entropy | +------------+------------+-------------------------------------+ | LEDC | on-chip | pwm | +------------+------------+-------------------------------------+ | MCPWM | on-chip | pwm | +------------+------------+-------------------------------------+ | PCNT | on-chip | qdec | +------------+------------+-------------------------------------+ | SPI DMA | on-chip | spi | +------------+------------+-------------------------------------+ | TWAI | on-chip | can | +------------+------------+-------------------------------------+ | ADC | on-chip | adc | +------------+------------+-------------------------------------+ | DAC | on-chip | dac | +------------+------------+-------------------------------------+ | Wi-Fi | on-chip | | +------------+------------+-------------------------------------+ | Bluetooth | on-chip | | +------------+------------+-------------------------------------+ 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 ******************* Simple boot =========== The board could be loaded using the single binary image, without 2nd stage bootloader. It is the default option when building the application without additional configuration. .. note:: Simple boot does not provide any security features nor OTA updates. MCUboot bootloader ================== User may choose to use MCUboot bootloader instead. In that case the bootloader must be built (and flashed) at least once. There are two options to be used when building an application: 1. Sysbuild 2. Manual build .. note:: User can select the MCUboot bootloader by adding the following line to the board default configuration file. .. code:: cfg CONFIG_BOOTLOADER_MCUBOOT=y Sysbuild ======== The sysbuild makes possible to build and flash all necessary images needed to bootstrap the board with the ESP32 SoC. To build the sample application using sysbuild use the command: .. zephyr-app-commands:: :tool: west :zephyr-app: samples/hello_world :board: esp32_devkitc_wrover :goals: build :west-args: --sysbuild :compact: By default, the ESP32 sysbuild creates bootloader (MCUboot) and application images. But it can be configured to create other kind of images. Build directory structure created by sysbuild is different from traditional Zephyr build. Output is structured by the domain subdirectories: .. code-block:: build/ ├── hello_world │ └── zephyr │ ├── zephyr.elf │ └── zephyr.bin ├── mcuboot │ └── zephyr │ ├── zephyr.elf │ └── zephyr.bin └── domains.yaml .. note:: With ``--sysbuild`` option the bootloader will be re-build and re-flash every time the pristine build is used. For more information about the system build please read the :ref:`sysbuild` documentation. Manual build ============ During the development cycle, it is intended to build & flash as quickly possible. For that reason, images can be built one at a time using traditional build. The instructions following are relevant for both manual build and sysbuild. The only difference is the structure of the build directory. .. note:: Remember that bootloader (MCUboot) needs to be flash at least once. 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: esp32_devkitc_wrover/esp32/procpu :goals: build The usual ``flash`` target will work with the ``esp32_devkitc_wrover`` board configuration. Here is an example for the :zephyr:code-sample:`hello_world` application. .. zephyr-app-commands:: :zephyr-app: samples/hello_world :board: esp32_devkitc_wrover/esp32/procpu :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! esp32_devkitc_wrover Debugging ********* ESP32 support on OpenOCD is available at `OpenOCD ESP32`_. On the ESP32-DevKitC-WROVER board, the JTAG pins are not run to a standard connector (e.g. ARM 20-pin) and need to be manually connected to the external programmer (e.g. a Flyswatter2): +------------+-----------+ | ESP32 pin | JTAG pin | +============+===========+ | 3V3 | VTRef | +------------+-----------+ | EN | nTRST | +------------+-----------+ | IO14 | TMS | +------------+-----------+ | IO12 | TDI | +------------+-----------+ | GND | GND | +------------+-----------+ | IO13 | TCK | +------------+-----------+ | IO15 | TDO | +------------+-----------+ Further documentation can be obtained from the SoC vendor in `JTAG debugging for ESP32`_. Here is an example for building the :zephyr:code-sample:`hello_world` application. .. zephyr-app-commands:: :zephyr-app: samples/hello_world :board: esp32_devkitc_wrover/esp32/procpu :goals: build flash You can debug an application in the usual way. Here is an example for the :zephyr:code-sample:`hello_world` application. .. zephyr-app-commands:: :zephyr-app: samples/hello_world :board: esp32_devkitc_wrover/esp32/procpu :goals: debug Note on Debugging with GDB Stub =============================== GDB stub is enabled on ESP32. * When adding breakpoints, please use hardware breakpoints with command ``hbreak``. Command ``break`` uses software breakpoints which requires modifying memory content to insert break/trap instructions. This does not work as the code is on flash which cannot be randomly accessed for modification. References ********** .. target-notes:: .. _`ESP32-DevKitC-WROVER`: https://docs.espressif.com/projects/esp-idf/en/stable/esp32/hw-reference/esp32/get-started-devkitc.html# .. _`ESP32 Datasheet`: https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf .. _`ESP32 Technical Reference Manual`: https://espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf .. _`JTAG debugging for ESP32`: https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/jtag-debugging/index.html .. _`OpenOCD ESP32`: https://github.com/espressif/openocd-esp32/releases