This document is intended to help users set up the software environment for development of applications using hardware based on the Espressif ESP32. Through a simple example we would like to illustrate how to use ESP-IDF (Espressif IoT Development Framework), including the menu based configuration, compiling the ESP-IDF and firmware download to ESP32 boards.
ESP32 integrates Wi-Fi (2.4 GHz band) and Bluetooth 4.2 solutions on a single chip, along with dual high performance cores, Ultra Low Power co-processor and several peripherals. Powered by 40 nm technology, ESP32 provides a robust, highly integrated platform to meet the continuous demands for efficient power usage, compact design, security, high performance, and reliability.
Espressif provides the basic hardware and software resources that help application developers to build their ideas around the ESP32 series hardware. The software development framework by Espressif is intended for rapidly developing Internet-of-Things (IoT) applications, with Wi-Fi, Bluetooth, power management and several other system features.
What You Need
=============
To develop applications for ESP32 you need:
***PC** loaded with either Windows, Linux or Mac operating system
***Toolchain** to compile code for ESP32
***Build tools** CMake and Ninja to build a full **Application** for ESP32
***ESP-IDF** that essentially contains API for ESP32 and scripts to operate the **Toolchain**
* A text editor to write programs (**Projects**) in C, e.g. `Eclipse <https://www.eclipse.org/>`_
* The **ESP32** board itself and a **USB cable** to connect it to the **PC**
We are an using ``esp`` subdirectory in your user's home directory (``~/esp`` on Linux and MacOS, ``%userprofile%\esp`` on Windows) to install everything needed for ESP-IDF. You can use any different directory, but will need to adjust the respective commands.
Depending on your experience and preferences, instead of using a prebuilt toolchain, you may want to customize your environment. To set up the system your own way go to Section :ref:`get-started-customized-setup-cmake`.
Besides the toolchain (that contains programs to compile and build the application), you also need ESP32 specific API / libraries. They are provided by Espressif in `ESP-IDF repository <https://github.com/espressif/esp-idf>`_. To get it, open terminal, navigate to the directory you want to put ESP-IDF, and clone it using ``git clone`` command.
Setting may be done manually, each time PC is restarted. Another option is to set them permanently in user profile. To do this, follow instructions specific to :ref:`Windows <add-paths-to-profile-windows-cmake>` , :ref:`Linux and MacOS <add-idf_path-to-profile-linux-macos-cmake>` in Section :doc:`add-idf_path-to-profile`.
.._get-started-get-packages-cmake:
Step 4. Install the Required Python Packages
============================================
Python packages required by ESP-IDF are located in the ``$IDF_PATH/requirements.txt`` file. You can install them by running::
Now you are ready to prepare your application for ESP32. To start off quickly, we will use :example:`get-started/hello_world` project from :idf:`examples` directory in IDF.
Copy :example:`get-started/hello_world` to ``~/esp`` directory:
You can also find a range of example projects under the :idf:`examples` directory in ESP-IDF. These example project directories can be copied in the same way as presented above, to begin your own projects.
It is also possible to build examples in-place, without copying them first.
..important::
The esp-idf build system does not support spaces in the path to either esp-idf or to projects.
You are almost there. To be able to proceed further, connect ESP32 board to PC, check under what serial port the board is visible and verify if serial communication works. If you are not sure how to do it, check instructions in Section :doc:`establish-serial-connection`. Note the port number, as it will be required in the next step.
..note:: If you get an error about ``idf.py`` not being found, check the ``tools`` directory is part of your Path as described above in :ref:`get-started-setup-path-cmake`. If there is no ``idf.py`` in the ``tools`` directory, check you have the correct branch for the CMake preview as shown under :ref:`get-started-get-esp-idf-cmake`.
..note:: Windows users, the Python 2.7 installer will try to configure Windows to associate files with a ``.py`` extension with Python 2. If a separate installed program (such as Visual Studio Python Tools) has created an association with a different version of Python, then running ``idf.py`` may not work (it opens the file in Visual Studio instead). You can either run ``C:\Python27\python idf.py`` each time instead, or change the association that Windows uses for ``.py`` files.
..note:: Linux users, if your default version of Python is 3.x then you may need to run ``python2 idf.py`` instead.
If previous steps have been done correctly, the following menu will be displayed:
Here are couple of tips on navigation and use of ``menuconfig``:
* Use up & down arrow keys to navigate the menu.
* Use Enter key to go into a submenu, Escape key to go up a level or exit.
* Type ``?`` to see a help screen. Enter key exits the help screen.
* Use Space key, or ``Y`` and ``N`` keys to enable (Yes) and disable (No) configuration items with checkboxes "``[*]``"
* Pressing ``?`` while highlighting a configuration item displays help about that item.
* Type ``/`` to search the configuration items.
..attention::
When using ESP32-DevKitC board with ESP32-SOLO-1 module, enable single core mode (:ref:`CONFIG_FREERTOS_UNICORE`) in menuconfig before flashing example applications.
Now you can flash the application to the ESP32 board. Run::
idf.py -p PORT flash
Replace PORT with the name of your ESP32 board's serial port. On Windows, serial ports have names like ``COM1``. On MacOS, they start with ``/dev/cu.``. On Linux, they start with ``/dev/tty``. See :doc:`establish-serial-connection` for full details.
This step will flash the binaries that you just built to your ESP32 board.
..note:: Running ``idf.py build`` before ``idf.py flash`` is not actually necessary, the flash step will automatically build the project if required before flashing.
..code-block:: none
Running esptool.py in directory [...]/esp/hello_world
To see if "hello_world" application is indeed running, type ``idf.py -p PORT monitor``. This command is launching :doc:`IDF Monitor <idf-monitor>` application::
$ idf.py -p /dev/ttyUSB0 monitor
Running idf_monitor in directory [...]/esp/hello_world/build
or monitor fails shortly after upload, your board is likely using 26MHz crystal. Most development board designs use 40MHz and the ESP-IDF uses this default value. Exit the monitor, go back to the :ref:`menuconfig <get-started-configure-cmake>`, change :ref:`CONFIG_ESP32_XTAL_FREQ_SEL` to 26MHz, then :ref:`build and flash <get-started-flash-cmake>` the application again. This is found under ``idf.py menuconfig`` under Component config --> ESP32-specific --> Main XTAL frequency.
..note::
You can combine building, flashing and monitoring into one step as follows::
You should update ESP-IDF from time to time, as newer versions fix bugs and provide new features. The simplest way to do the update is to delete the existing ``esp-idf`` folder and clone it again, as if performing the initial installation described in :ref:`get-started-get-esp-idf-cmake`.
If downloading to a new path, remember to :doc:`add-idf_path-to-profile` so that the toolchain scripts know where to find the ESP-IDF in its release specific location.
