.. _olimex_esp32_evb:

Olimex ESP32-EVB
################

Overview
********

The Olimex ESP32-EVB is an OSHW certified, open-source IoT board based on the
Espressif ESP32-WROOM-32E/UE module. It has a wired 100Mbit/s Ethernet Interface,
Bluetooth LE, WiFi, infrared remote control, and CAN connectivity. Two relays
allows switching power appliances on and off.

The board can operate from a single LiPo backup battery as it has an internal
LiPo battery charger. There is no step-up converter, so relays, CAN, and USB
power does not work when running off battery.

.. figure:: ./ESP32-EVB.jpg
   :width: 540px
   :align: center
   :alt: ESP32-EVB

   ESP32-EVB (Credit: Olimex)

Hardware
********

- ESP32-WROOM-32E/UE module with 4MB flash.
- On-board programmer, CH340T USB-to-UART
- WiFi, Bluetooth LE connectivity.
- 100Mbit/s Ethernet interface, Microchip LAN8710A PHY.
- MicroSD card slot.
- 2 x 10A/250VAC (15A/120VAC 15A/24VDC) relays with connectors and status LEDs.
- CAN interface, Microchip MCP2562-E high-speed CAN transceiver.
- IR receiver and transmitter, up to 5 meters distance.
- BL4054B LiPo battery charger with status LEDs for stand-alone operation during
  power outages.
- Power jack for external 5VDC power supply.
- Univeral EXTension (UEXT) connector for connecting UEXT modules.
- User push button.
- 40 pin GPIO connector with all ESP32 pins.

For more information about the ESP32-EVB and the ESP32-WROOM-32E/UE module, see
these reference documents:

- `ESP32-EVB Website`_
- `ESP32-EVB Schematic`_
- `ESP32-EVB GitHub Repository`_
- `ESP32-WROOM32-E/UE Datasheet`_

Supported Features
******************

The olimex_esp32_evb board configuration supports the following hardware
features:

+-----------+------------+-------------------------------------+
| Interface | Controller | Driver/Component                    |
+===========+============+=====================================+
| EFUSE     | on-chip    | hwinfo, device ID                   |
+-----------+------------+-------------------------------------+
| FLASH     | module     | External flash                      |
+-----------+------------+-------------------------------------+
| GPIO      | on-chip    | gpio                                |
+-----------+------------+-------------------------------------+
| I2C       | on-chip    | I2C                                 |
+-----------+------------+-------------------------------------+
| INTERRUPT | on-chip    | interrupt controller                |
+-----------+------------+-------------------------------------+
| IO_MUX    | on-chip    | pinctrl                             |
+-----------+------------+-------------------------------------+
| SPI       | on-chip    | spi                                 |
+-----------+------------+-------------------------------------+
| TIMG      | on-chip    | counter                             |
+-----------+------------+-------------------------------------+
| TRNG      | on-chip    | entropy                             |
+-----------+------------+-------------------------------------+
| TWAI      | on-chip    | CAN controller                      |
+-----------+------------+-------------------------------------+
| UART      | on-chip    | uart                                |
+-----------+------------+-------------------------------------+
| WDT       | on-chip    | watchdog                            |
+-----------+------------+-------------------------------------+
| WiFi      | on-chip    | WiFi                                |
+-----------+------------+-------------------------------------+

The default configuration can be found in the defconfig file:
``boards/xtensa/olimex_esp32_evb/olimex_esp32_evb_defconfig``.

Other hardware features are not currently supported by the port.

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

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

Espressif HAL requires binary blobs in order work. The west extension below performs the required
syncronization to clone, checkout and pull the submodules:

.. code-block:: console

   west espressif update

.. 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: olimex_esp32_evb
   :goals: build

The usual ``flash`` target will work with the ``olimex_esp32_evb`` board
configuration. Here is an example for the :ref:`hello_world`
application.

.. zephyr-app-commands::
   :zephyr-app: samples/hello_world
   :board: olimex_esp32_evb
   :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! olimex_esp32_evb

Debugging
---------

As with much custom hardware, the ESP32 modules require patches to
OpenOCD that are not upstreamed. Espressif maintains their own fork of
the project. The custom OpenOCD can be obtained by running the following extension:

.. code-block:: console

   west espressif install

.. note::

   By default, the OpenOCD will be downloaded and installed under $HOME/.espressif/tools/zephyr directory
   (%USERPROFILE%/.espressif/tools/zephyr on Windows).

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: olimex_esp32_evb
   :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: olimex_esp32_evb
   :goals: debug

.. _ESP32-EVB Website:
   https://www.olimex.com/Products/IoT/ESP32/ESP32-EVB/open-source-hardware

.. _ESP32-EVB Schematic:
   https://github.com/OLIMEX/ESP32-EVB/raw/master/HARDWARE/REV-I/ESP32-EVB_Rev_I.pdf

.. _ESP32-EVB GitHub Repository:
   https://github.com/OLIMEX/ESP32-EVB

.. _ESP32-WROOM32-E/UE Datasheet:
   https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32e_esp32-wroom-32ue_datasheet_en.pdf