| .. _esp_wrover_kit: |
| |
| ESP-WROVER-KIT |
| ############## |
| |
| Overview |
| ******** |
| |
| ESP-WROVER-KIT is an ESP32-based development board produced by `Espressif <https://www.espressif.com/>`_. |
| |
| ESP-WROVER-KIT features the following integrated components: |
| |
| - ESP32-WROVER-E module |
| - LCD screen |
| - MicroSD card slot |
| |
| Its another distinguishing feature is the embedded FTDI FT2232HL chip - an advanced multi-interface |
| USB bridge. This chip enables to use JTAG for direct debugging of ESP32 through the USB interface |
| without a separate JTAG debugger. ESP-WROVER-KIT makes development convenient, easy, and |
| cost-effective. |
| |
| Most of the ESP32 I/O pins are broken out to the board’s pin headers for easy access. |
| |
| .. note:: |
| ESP32’s GPIO16 and GPIO17 are used as chip select and clock signals for PSRAM. By default, the two |
| GPIOs are not broken out to the board’s pin headers in order to ensure reliable performance. |
| |
| Functionality Overview |
| ********************** |
| |
| The block diagram below shows the main components of ESP-WROVER-KIT and their interconnections. |
| |
| .. image:: img/esp-wrover-kit-block-diagram.png |
| :width: 837px |
| :align: center |
| :height: 415px |
| :alt: ESP-WROVER-KIT |
| |
| Functional Description |
| ********************** |
| |
| The following two figures and the table below describe the key components, interfaces, and controls |
| of the ESP-WROVER-KIT board. |
| |
| .. figure:: img/esp-wrover-kit-v4.1-layout-front.png |
| :align: center |
| :alt: esp wrover front |
| |
| ESP-WROVER-KIT board layout - front |
| |
| .. _esp wrover back: |
| |
| .. figure:: img/esp-wrover-kit-v4.1-layout-back.png |
| :align: center |
| :alt: esp wrover back |
| |
| ESP-WROVER-KIT board layout - back |
| |
| The table below provides description in the following manner: |
| - Starting from the first picture’s top right corner and going clockwise |
| - Then moving on to the second picture |
| |
| +------------------+-------------------------------------------------------------------------+ |
| | Key Component | Description | |
| +==================+=========================================================================+ |
| | FT2232 | The FT2232 chip serves as a multi-protocol USB-to-serial bridge | |
| | | which can be programmed and controlled via USB to provide | |
| | | communication with ESP32. FT2232 also features USB-to-JTAG | |
| | | interface which is available on channel A of the chip, while USB-to- | |
| | | serial is on channel B. The FT2232 chip enhances user-friendliness in | |
| | | terms of application development and debugging. See `ESP-WROVER-KIT | |
| | | V4.1 schematic | |
| | | <https://dl.espressif.com/dl/schematics/ESP-WROVER-KIT_V4_1.pdf>`_. | |
| +------------------+-------------------------------------------------------------------------+ |
| | 32.768 kHz | External precision 32.768 kHz crystal oscillator serves as a clock with | |
| | | low-power consumption while the chip is in Deep-sleep mode. | |
| +------------------+-------------------------------------------------------------------------+ |
| | 0R | Zero-ohm resistor intended as a placeholder for a current shunt, can | |
| | | be desoldered or replaced with a current shunt to facilitate the | |
| | | measurement of ESP32’s current consumption in different modes. | |
| +------------------+-------------------------------------------------------------------------+ |
| | ESP32-WROVER-E | This ESP32 module features 64-Mbit PSRAM for flexible extended | |
| | module | storage and data processing capabilities. | |
| +------------------+-------------------------------------------------------------------------+ |
| | Diagnostic LEDs | Four red LEDs connected to the GPIO pins of FT2232. Intended for | |
| | | future use. | |
| +------------------+-------------------------------------------------------------------------+ |
| | UART | Serial port. The serial TX/RX signals of FT2232 and ESP32 are broken | |
| | | out to the inward and outward sides of JP2 respectively. By default, | |
| | | these pairs of pins are connected with jumpers. To use ESP32’s serial | |
| | | interface, remove the jumpers and connect another external serial | |
| | | device to the respective pins. | |
| +------------------+-------------------------------------------------------------------------+ |
| | SPI | By default, ESP32 uses its SPI interface to access flash and PSRAM | |
| | | memory inside the module. Use these pins to connect ESP32 to | |
| | | another SPI device. In this case, an extra chip select (CS) signal is | |
| | | needed. Please note that the voltage of this interface is 3.3 V. | |
| +------------------+-------------------------------------------------------------------------+ |
| | CTS/RTS | Serial port flow control signals: the pins are not connected to the | |
| | | circuitry by default. To enable them, short the respective pins of JP14 | |
| | | with jumpers. | |
| +------------------+-------------------------------------------------------------------------+ |
| | JTAG | JTAG interface. JTAG signals of FT2232 and ESP32 are broken out to | |
| | | the inward and outward sides of JP2 respectively. By default, these | |
| | | pairs of pins are disconnected. To enable JTAG, short the respective | |
| | | pins with jumpers as shown in Section | |
| | | :ref:`Setup Options<setup options>` | |
| +------------------+-------------------------------------------------------------------------+ |
| | USB Port | USB interface. Power supply for the board as well as the | |
| | | communication interface between a computer and the board. | |
| +------------------+-------------------------------------------------------------------------+ |
| | EN Button | Reset button. | |
| +------------------+-------------------------------------------------------------------------+ |
| | BOOT Button | Download button. Holding down Boot and then pressing EN initiates | |
| | | Firmware Download mode for downloading firmware through the | |
| +------------------+-------------------------------------------------------------------------+ |
| | Power Switch | Power On/Off Switch. Toggling toward the Boot button powers the | |
| | | board on, toggling away from Boot powers the board off. | |
| +------------------+-------------------------------------------------------------------------+ |
| | Power Selector | Power supply selector interface. The board can be powered either via | |
| | | USB or via the 5V Input interface. Select the power source with a | |
| | | jumper. For more details, see Section Setup Options, jumper header | |
| | | JP7. | |
| +------------------+-------------------------------------------------------------------------+ |
| | 5V input | 5V power supply interface for a standard coaxial power connector, | |
| | | 5.5 x 2.1 mm, center positive. This interface can be more convenient | |
| | | when the board is operating autonomously (not connected to a | |
| | | computer). | |
| +------------------+-------------------------------------------------------------------------+ |
| | 5V Power On LED | This red LED turns on when power is supplied to the board, either | |
| | | from USB or 5V Input. | |
| +------------------+-------------------------------------------------------------------------+ |
| | LDO | NCP1117(1A). 5V-to-3.3V LDO. NCP1117 can provide a maximum | |
| | | current of 1A. The LDO on the board has a fixed output voltage. | |
| | | Although, the user can install an LDO with adjustable output voltage. | |
| | | For details, please refer to `ESP-WROVER-KIT V4.1 schematic | |
| | | <https://dl.espressif.com/dl/schematics/ESP-WROVER-KIT_V4_1.pdf>`_. | |
| +------------------+-------------------------------------------------------------------------+ |
| | Camera Connector | Camera interface, a standard OV7670 camera module. | |
| +------------------+-------------------------------------------------------------------------+ |
| | RGB LED | Red, green and blue (RGB) light emitting diodes (LEDs), can be | |
| | | controlled by pulse width modulation (PWM). | |
| +------------------+-------------------------------------------------------------------------+ |
| | I/O Connector | All the pins on the ESP32 module are broken out to pin headers. You | |
| | | can program ESP32 to enable multiple functions, such as PWM, ADC, | |
| | | DAC, I2C, I2S, SPI, etc. | |
| +------------------+-------------------------------------------------------------------------+ |
| | MicroSD Card | Useful for developing applications that access MicroSD card for data | |
| | Slot | storage and retrieval. | |
| +------------------+-------------------------------------------------------------------------+ |
| | LCD | Support for mounting and interfacing a 3.2” SPI (standard 4-wire | |
| | | Serial Peripheral Interface) LCD, as shown on figure | |
| | | :ref:`ESP-WROVER-KIT board layout - back<esp wrover back>` | |
| +------------------+-------------------------------------------------------------------------+ |
| |
| .. _setup options: |
| |
| Setup Options |
| ************* |
| |
| There are three jumper blocks available to set up the board functionality. The most frequently |
| required options are listed in the table below. |
| |
| .. |jmpextpwr| image:: img/esp-wrover-kit-v4.1-jp7-ext_5v.jpg |
| |
| .. |jmpusbpwr| image:: img/esp-wrover-kit-v4.1-jp7-usb_5v.jpg |
| |
| .. |jmpjtag| image:: img/esp-wrover-kit-v4.1-jp2-jtag.jpg |
| |
| .. |jmpuart| image:: img/esp-wrover-kit-v4.1-jp2-tx-rx.jpg |
| |
| .. |jmpctrl| image:: img/esp-wrover-kit-v4.1-jp14.jpg |
| |
| +------------------+--------------------------------------------------------------+ |
| | Header | Jumper Setting | Description of Functionality | |
| +========+================+=======================================================+ |
| | JP7 | |jmpextpwr| | Power ESP-WROVER-KIT via an external power supply | |
| +--------+----------------+-------------------------------------------------------+ |
| | JP7 | |jmpusbpwr| | Power ESP-WROVER-KIT via USB | |
| +--------+----------------+-------------------------------------------------------+ |
| | JP2 | |jmpjtag| | Enable JTAG functionality | |
| +--------+----------------+-------------------------------------------------------+ |
| | JP2 | |jmpuart| | Enable UART communication | |
| +--------+----------------+-------------------------------------------------------+ |
| | JP14 | |jmpctrl| | Enable RTS/CTS flow control for serial communication | |
| +--------+----------------+-------------------------------------------------------+ |
| |
| Allocation of ESP32 Pins |
| ************************ |
| |
| Some pins / terminals of ESP32 are allocated for use with the onboard or external hardware. If |
| that hardware is not used, e.g., nothing is plugged into the Camera (JP4) header, then these |
| GPIOs can be used for other purposes. |
| |
| Some of the pins, such as GPIO0 or GPIO2, have multiple functions and some of them are shared |
| among onboard and external peripheral devices. Certain combinations of peripherals cannot work |
| together. For example, it is not possible to do JTAG debugging of an application that is using |
| SD card, because several pins are shared by JTAG and the SD card slot. |
| |
| In other cases, peripherals can coexist under certain conditions. This is applicable to, for |
| example, LCD screen and SD card that share only a single pin GPIO21. This pin is used to provide |
| D/C (Data / Control) signal for the LCD as well as the Card Detect signal read from the SD card |
| slot. If the card detect functionality is not essential, then it may be disabled by removing R167, |
| so both LCD and SD may operate together. |
| |
| For more details on which pins are shared among which peripherals, please refer to the table in |
| the next section. |
| |
| Main I/O Connector / JP1 |
| ************************ |
| |
| The JP1 connector consists of 14x2 male pins whose functions are shown in the middle two “I/O” |
| columns of the table below. The two “Shared With” columns on both sides describe where else on |
| the board a certain GPIO is used. |
| |
| +-------------------+------+------+----------------------+ |
| | Shared With | I/O | I/O | Shared With | |
| +===================+======+======+======================+ |
| | n/a | 3.3V | GND | n/a | |
| +-------------------+------+------+----------------------+ |
| | NC/XTAL | IO32 | IO33 | NC/XTAL | |
| +-------------------+------+------+----------------------+ |
| | JTAG, MicroSD | IO12 | IO13 | JTAG, MicroSD | |
| +-------------------+------+------+----------------------+ |
| | JTAG, MicroSD | IO14 | IO27 | Camera | |
| +-------------------+------+------+----------------------+ |
| | Camera | IO26 | IO25 | Camera, LCD | |
| +-------------------+------+------+----------------------+ |
| | Camera | IO35 | IO34 | Camera | |
| +-------------------+------+------+----------------------+ |
| | Camera | IO39 | IO36 | Camera | |
| +-------------------+------+------+----------------------+ |
| | JTAG | EN | IO23 | Camera, LCD | |
| +-------------------+------+------+----------------------+ |
| | Camera, LCD | IO22 | IO21 | Camera, LCD, MicroSD | |
| +-------------------+------+------+----------------------+ |
| | Camera, LCD | IO19 | IO18 | Camera, LCD | |
| +-------------------+------+------+----------------------+ |
| | Camera, LCD | IO5 | IO17 | PSRAM | |
| +-------------------+------+------+----------------------+ |
| | PSRAM | IO16 | IO4 | LED, Camera, MicroSD | |
| +-------------------+------+------+----------------------+ |
| | Camera, LED, Boot | IO0 | IO2 | LED, MicroSD | |
| +-------------------+------+------+----------------------+ |
| | JTAG, MicroSD | IO15 | 5V | | |
| +-------------------+------+------+----------------------+ |
| |
| Legend: |
| |
| - NC/XTAL - 32.768 kHz Oscillator |
| - JTAG - JTAG / JP2 |
| - Boot - Boot button / SW2 |
| - Camera - Camera / JP4 |
| - LED - RGB LED |
| - MicroSD - MicroSD Card / J4 |
| - LCD - LCD / U5 |
| - PSRAM - ESP32-WROVER-E’s PSRAM |
| |
| 32.768 kHz Oscillator |
| ********************* |
| |
| +---+-----------+ |
| | . | ESP32 Pin | |
| +===+===========+ |
| | 1 | GPIO32 | |
| +---+-----------+ |
| | 2 | GPIO33 | |
| +---+-----------+ |
| |
| .. note:: |
| Since GPIO32 and GPIO33 are connected to the oscillator by default, they are not connected to |
| the JP1 I/O connector to maintain signal integrity. This allocation may be changed from the |
| oscillator to JP1 by desoldering the zero-ohm resistors from positions R11 / R23 and re- |
| soldering them to positions R12 / R24. |
| |
| SPI Flash / JP2 |
| *************** |
| |
| +---+--------------+ |
| | . | ESP32 Pin | |
| +===+==============+ |
| | 1 | CLK / GPIO6 | |
| +---+--------------+ |
| | 2 | SD0 / GPIO7 | |
| +---+--------------+ |
| | 3 | SD1 / GPIO8 | |
| +---+--------------+ |
| | 4 | SD2 / GPIO9 | |
| +---+--------------+ |
| | 5 | SD3 / GPIO10 | |
| +---+--------------+ |
| | 6 | CDM / GPIO11 | |
| +---+--------------+ |
| |
| .. important:: |
| The module’s flash bus is connected to the jumper block JP2 through zero-ohm resistors R140 ~ |
| R145. If the flash memory needs to operate at the frequency of 80 MHz, for reasons such as |
| improving the integrity of bus signals, you can desolder these resistors to disconnect the |
| module’s flash bus from the pin header JP2. |
| |
| JTAG / JP2 |
| ********** |
| |
| +---+---------------+-------------+ |
| | . | ESP32 Pin | JTAG Signal | |
| +===+===============+=============+ |
| | 1 | EN | TRST_N | |
| +---+---------------+-------------+ |
| | 2 | MTMS / GPIO14 | TMS | |
| +---+---------------+-------------+ |
| | 3 | MTDO / GPIO15 | TDO | |
| +---+---------------+-------------+ |
| | 4 | MTDI / GPIO12 | TDI | |
| +---+---------------+-------------+ |
| | 5 | MTCK / GPIO13 | TCK | |
| +---+---------------+-------------+ |
| |
| Camera / JP4 |
| ************ |
| |
| +----+-----------+-----------------------------+ |
| | . | ESP32 Pin | Camera Signal | |
| +====+===========+=============================+ |
| | 1 | n/a | 3.3V | |
| +----+-----------+-----------------------------+ |
| | 2 | n/a | Ground | |
| +----+-----------+-----------------------------+ |
| | 3 | GPIO27 | SIO_C / SCCB Clock | |
| +----+-----------+-----------------------------+ |
| | 4 | GPIO26 | SIO_D / SCCB Data | |
| +----+-----------+-----------------------------+ |
| | 5 | GPIO25 | VSYNC / Vertical Sync | |
| +----+-----------+-----------------------------+ |
| | 6 | GPIO23 | HREF / Horizontal Reference | |
| +----+-----------+-----------------------------+ |
| | 7 | GPIO22 | PCLK / Pixel Clock | |
| +----+-----------+-----------------------------+ |
| | 8 | GPIO21 | XCLK / System Clock | |
| +----+-----------+-----------------------------+ |
| | 9 | GPIO35 | D7 / Pixel Data Bit 7 | |
| +----+-----------+-----------------------------+ |
| | 10 | GPIO34 | D6 / Pixel Data Bit 6 | |
| +----+-----------+-----------------------------+ |
| | 11 | GPIO39 | D5 / Pixel Data Bit 5 | |
| +----+-----------+-----------------------------+ |
| | 12 | GPIO36 | D4 / Pixel Data Bit 4 | |
| +----+-----------+-----------------------------+ |
| | 13 | GPIO19 | D3 / Pixel Data Bit 3 | |
| +----+-----------+-----------------------------+ |
| | 14 | GPIO18 | D2 / Pixel Data Bit 2 | |
| +----+-----------+-----------------------------+ |
| | 15 | GPIO5 | D1 / Pixel Data Bit 1 | |
| +----+-----------+-----------------------------+ |
| | 16 | GPIO4 | D0 / Pixel Data Bit 0 | |
| +----+-----------+-----------------------------+ |
| | 17 | GPIO0 | RESET / Camera Reset | |
| +----+-----------+-----------------------------+ |
| | 18 | n/a | PWDN / Camera Power Down | |
| +----+-----------+-----------------------------+ |
| |
| - Signals D0 .. D7 denote camera data bus |
| |
| RGB LED |
| ******* |
| |
| +----+-----------+---------+ |
| | . | ESP32 Pin | RGB LED | |
| +====+===========+=========+ |
| | 1 | GPIO0 | Red | |
| +----+-----------+---------+ |
| | 2 | GPIO2 | Green | |
| +----+-----------+---------+ |
| | 3 | GPIO4 | Blue | |
| +----+-----------+---------+ |
| |
| MicroSD Card |
| ************ |
| |
| +---+---------------+----------------+ |
| | . | ESP32 Pin | MicroSD Signal | |
| +===+===============+================+ |
| | 1 | MTDI / GPIO12 | DATA2 | |
| +---+---------------+----------------+ |
| | 2 | MTCK / GPIO13 | CD / DATA3 | |
| +---+---------------+----------------+ |
| | 3 | MTDO / GPIO15 | CMD | |
| +---+---------------+----------------+ |
| | 4 | MTMS / GPIO14 | CLK | |
| +---+---------------+----------------+ |
| | 5 | GPIO2 | DATA0 | |
| +---+---------------+----------------+ |
| | 6 | GPIO4 | DATA1 | |
| +---+---------------+----------------+ |
| | 7 | GPIO21 | Card Detect | |
| +---+---------------+----------------+ |
| |
| LCD / U5 |
| ******** |
| |
| +---+-----------+------------+ |
| | . | ESP32 Pin | LCD Signal | |
| +===+===========+============+ |
| | 1 | GPIO18 | RESET | |
| +---+-----------+------------+ |
| | 2 | GPIO19 | SCL | |
| +---+-----------+------------+ |
| | 3 | GPIO21 | D/C | |
| +---+-----------+------------+ |
| | 4 | GPIO22 | CS | |
| +---+-----------+------------+ |
| | 5 | GPIO23 | SDA | |
| +---+-----------+------------+ |
| | 6 | GPIO25 | SDO | |
| +---+-----------+------------+ |
| | 7 | GPIO5 | Backlight | |
| +---+-----------+------------+ |
| |
| Start Application Development |
| ***************************** |
| |
| Before powering up your ESP-WROVER-KIT, please make sure that the board is in good |
| condition with no obvious signs of damage. |
| |
| Initial Setup |
| ************* |
| |
| Please set only the following jumpers shown in the pictures below: |
| |
| - Select USB as the power source using the jumper block JP7. |
| - Enable UART communication using the jumper block JP2. |
| |
| +------------------------+---------------------------+ |
| | Power up from USB port | Enable UART communication | |
| +========+===============+===========================+ |
| | |jmpusbpwr| | |jmpuart| | |
| +------------------------+---------------------------+ |
| |
| Do not install any other jumpers. |
| |
| Turn the Power Switch to ON, the 5V Power On LED should light up. |
| |
| System requirements |
| ******************* |
| |
| Build Environment Setup |
| ======================= |
| |
| Some variables must be exported into the environment prior to building this port. |
| Find more information at :ref:`env_vars` on how to keep this settings saved in you environment. |
| |
| .. note:: |
| |
| In case of manual toolchain installation, set :file:`ESPRESSIF_TOOLCHAIN_PATH` accordingly. |
| Otherwise, set toolchain path as below. If necessary. |
| |
| On Linux and macOS: |
| |
| .. code-block:: console |
| |
| export ZEPHYR_TOOLCHAIN_VARIANT="espressif" |
| export ESPRESSIF_TOOLCHAIN_PATH="${HOME}/.espressif/tools/zephyr" |
| |
| On Windows: |
| |
| .. code-block:: console |
| |
| # on CMD: |
| set ESPRESSIF_TOOLCHAIN_PATH=%USERPROFILE%\.espressif\tools\zephyr |
| set ZEPHYR_TOOLCHAIN_VARIANT=espressif |
| |
| # on PowerShell |
| $env:ESPRESSIF_TOOLCHAIN_PATH="$env:USERPROFILE\.espressif\tools\zephyr" |
| $env:ZEPHYR_TOOLCHAIN_VARIANT="espressif" |
| |
| Finally, retrieve required submodules to build this port. This might take a while for the first time: |
| |
| .. code-block:: console |
| |
| west espressif update |
| |
| .. note:: |
| |
| It is recommended running the command above after :file:`west update` so that submodules also get updated. |
| |
| Flashing |
| ======== |
| |
| The usual ``flash`` target will work with the ``esp_wrover_kit`` board |
| configuration. Here is an example for the :ref:`hello_world` |
| application. |
| |
| .. zephyr-app-commands:: |
| :zephyr-app: samples/hello_world |
| :board: esp_wrover_kit |
| :goals: flash |
| |
| Refer to :ref:`build_an_application` and :ref:`application_run` for |
| more details. |
| |
| It's impossible to determine which serial port the ESP-WROVER-KIT board is |
| connected to, as it uses a generic RS232-USB converter. The default of |
| ``/dev/ttyUSB1`` is provided as that's often the assigned name on a Linux |
| machine without any other such converters. |
| |
| The baud rate of 921600bps is recommended. If experiencing issues when |
| flashing, try halving the value a few times (460800, 230400, 115200, |
| etc). |
| |
| All flashing options are now handled by the :ref:`west` tool, including flashing |
| with custom options such as a different serial port. The ``west`` tool supports |
| specific options for the ESP32-S2 board, as listed here: |
| |
| --esp-idf-path ESP_IDF_PATH |
| path to ESP-IDF |
| --esp-device ESP_DEVICE |
| serial port to flash, default $ESPTOOL_PORT if defined. |
| If not, esptool will loop over available serial ports until |
| it finds ESP32 device to flash. |
| --esp-baud-rate ESP_BAUD_RATE |
| serial baud rate, default 921600 |
| --esp-flash-size ESP_FLASH_SIZE |
| flash size, default "detect" |
| --esp-flash-freq ESP_FLASH_FREQ |
| flash frequency, default "40m" |
| --esp-flash-mode ESP_FLASH_MODE |
| flash mode, default "dio" |
| --esp-tool ESP_TOOL if given, complete path to espidf. default is to |
| search for it in ``[ESP_IDF_PATH]/components/esptool_py/ |
| esptool/esptool.py`` |
| --esp-flash-bootloader ESP_FLASH_BOOTLOADER |
| Bootloader image to flash |
| --esp-flash-partition_table ESP_FLASH_PARTITION_TABLE |
| Partition table to flash |
| |
| For example, to flash to ``/dev/ttyUSB2``, use the following command after |
| having build the application in the ``build`` directory: |
| |
| |
| .. code-block:: console |
| |
| west flash -d build/ --skip-rebuild --esp-device /dev/ttyUSB2 |
| |
| |
| Related Documents |
| ***************** |
| |
| - `ESP-WROVER-KIT V4.1 schematic <https://dl.espressif.com/dl/schematics/ESP-WROVER-KIT_V4_1.pdf>`_ (PDF) |
| - `ESP-WROVER-KIT V4.1 layout <https://dl.espressif.com/dl/schematics/ESP-WROVER-KIT_V4.1.dxf>`_ (DXF) |
| - `ESP32 Datasheet <https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf>`_ (PDF) |
| - `ESP32-WROVER-E Datasheet <https://www.espressif.com/sites/default/files/documentation/esp32-wrover-e_esp32-wrover-ie_datasheet_en.pdf>`_ (PDF) |
| - `ESP32 Hardware Reference <https://docs.espressif.com/projects/esp-idf/en/latest/esp32/hw-reference/index.html>`_ |
