This document is intended to help users set up the software environment for developement 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.
Introduction
============
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.
Preparation of development environment consists of three steps:
1. Setup of **Toolchain**
2. Getting of **ESP-IDF** from GitHub
3. Installation and configuration of **Eclipse**
You may skip the last step, if you prefer to use different editor.
Having environment set up, you are ready to start the most interesting part - the application development. This process may be summarized in four steps:
1. Configuration of a **Project** and writing the code
2. Compilation of the **Project** and linking it to build an **Application**
3. Flashing (uploading) of the **Application** to **ESP32**
4. Monitoring / debugging of the **Application**
See instructions below that will walk you through these steps.
Guides
======
If you have one of ESP32 development boards listed below, click on provided links to get you up and running.
..toctree::
:maxdepth:1
ESP32 DevKitC <get-started-devkitc>
ESP-WROVER-KIT <get-started-wrover-kit>
If you have different board, move to sections below.
We are using ``~/esp`` directory to install the prebuilt toolchain, ESP-IDF and sample applications. You can use different directory, but need to adjust 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`.
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::
ESP-IDF will be downloaded into ``~/esp/esp-idf``.
..note::
Do not miss the ``--recursive`` option. If you have already cloned ESP-IDF without this option, run another command to get all the submodules::
cd ~/esp/esp-idf
git submodule update --init
..note::
While cloning submodules on **Windows** platform, the ``git clone`` command may print some output starting ``': not a valid identifier...``. This is a `known issue <https://github.com/espressif/esp-idf/issues/11>`_ but the git clone still succeeds without any problems.
.._get-started-setup-path:
Setup Path to ESP-IDF
=====================
The toolchain programs access ESP-IDF using ``IDF_PATH`` environment variable. This variable should be set up on your PC, otherwise projects will not build. Setting may be done manually, each time PC is restarted. Another option is to set up it permanently by defining ``IDF_PATH`` in user profile. To do so, follow instructions specific to :ref:`Windows <add-idf_path-to-profile-windows>` , :ref:`Linux and MacOS <add-idf_path-to-profile-linux-macos>` in section :doc:`add-idf_path-to-profile`.
.._get-started-start-project:
Start a Project
===============
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.
..important::
The esp-idf build system does not support spaces in paths to esp-idf or to projects.
.._get-started-connect:
Connect
=======
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.
.._get-started-configure:
Configure
=========
Being in terminal window, go to directory of ``hello_world`` application by typing ``cd ~/esp/hello_world``. Then start project configuration utility ``menuconfig``::
cd ~/esp/hello_world
make menuconfig
If previous steps have been done correctly, the following menu will be displayed:
..figure:: ../_static/project-configuration.png
:align:center
:alt:Project configuration - Home window
:figclass:align-center
Project configuration - Home window
In the menu, navigate to ``Serial flasher config`` > ``Default serial port`` to configure the serial port, where project will be loaded to. Confirm selection by pressing enter, save configuration by selecting ``< Save >`` and then exit application by selecting ``< Exit >``.
Most ESP32 development boards have a 40MHz crystal installed. However, some boards use a 26MHz crystal. If your board uses a 26MHz crystal, or you get garbage output from serial port after code upload, adjust the :ref:`CONFIG_ESP32_XTAL_FREQ` option in menuconfig.
Now you can build and flash the application. Run::
make flash
This will compile the application and all the ESP-IDF components, generate bootloader, partition table, and application binaries, and flash these binaries to your ESP32 board.
..highlight:: none
::
esptool.py v2.0-beta2
Flashing binaries to serial port /dev/ttyUSB0 (app at offset 0x10000)...
esptool.py v2.0-beta2
Connecting........___
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.
Attaching SPI flash...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x0220
Compressed 11616 bytes to 6695...
Wrote 11616 bytes (6695 compressed) at 0x00001000 in 0.1 seconds (effective 920.5 kbit/s)...
Hash of data verified.
Compressed 408096 bytes to 171625...
Wrote 408096 bytes (171625 compressed) at 0x00010000 in 3.9 seconds (effective 847.3 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 82...
Wrote 3072 bytes (82 compressed) at 0x00008000 in 0.0 seconds (effective 8297.4 kbit/s)...
Hash of data verified.
Leaving...
Hard resetting...
If there are no issues, at the end of build process, you should see messages describing progress of loading process. Finally, the end module will be reset and "hello_world" application will start.
If you'd like to use the Eclipse IDE instead of running ``make``, check out the :doc:`Eclipse guide <eclipse-setup>`.
Several lines below, after start up and diagnostic log, you should see "Hello world!" printed out by the application. ::
...
Hello world!
Restarting in 10 seconds...
I (211) cpu_start: Starting scheduler on APP CPU.
Restarting in 9 seconds...
Restarting in 8 seconds...
Restarting in 7 seconds...
To exit monitor use shortcut ``Ctrl+]``. To execute ``make flash`` and ``make monitor`` in one shoot type ``make flash monitor``. Check section :doc:`IDF Monitor <idf-monitor>` for handy shortcuts and more details on using this application.
