Get Started (CMake)

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Note

This is documentation for the CMake-based build system which is currently in preview release. If you encounter any gaps or bugs, please report them in the Issues section of the ESP-IDF repository.

The CMake-based build system will become the default build system in ESP-IDF V4.0. The existing GNU Make based build system will be deprecated in ESP-IDF V5.0.

Important

The following features are not yet supported with the CMake-based build system:

  • Eclipse IDE Documentation
  • Secure Boot
  • Flash Encryption

Support for these features will be available before CMake becomes the default build system.

This document is intended to help you set up the software development environment for the hardware based on the ESP32 chip by Espressif.

After that, a simple example will show you how to use ESP-IDF (Espressif IoT Development Framework) for menu configuration, then building, and flashing firmware onto an ESP32 board.

Note

This is documentation for the master branch (latest version) of ESP-IDF. This version is under continual development. Stable version documentation is available, as well as other ESP-IDF Versions.

Introduction

ESP32 is a system on a chip that integrates the following features:

  • Wi-Fi (2.4 GHz band)
  • Bluetooth 4.2
  • Dual high performance cores
  • Ultra Low Power co-processor
  • Several peripherals

Powered by 40 nm technology, ESP32 provides a robust, highly integrated platform, which helps meet the continuous demands for efficient power usage, compact design, security, high performance, and reliability.

Espressif provides basic hardware and software resources to help application developers realize their ideas using the ESP32 series hardware. The software development framework by Espressif is intended for development of Internet-of-Things (IoT) applications with Wi-Fi, Bluetooth, power management and several other system features.

What You Need

Hardware:

  • An ESP32 board
  • USB cable - USB A / micro USB B
  • Computer running Windows, Linux, or macOS

Software:

  • Toolchain to compile code for ESP32
  • Build tools - CMake and Ninja to build a full Application for ESP32
  • ESP-IDF that essentially contains API (software libraries and source code) for ESP32 and scripts to operate the Toolchain
  • Text editor to write programs (Projects) in C, e.g., Eclipse
Development of applications for ESP32

Development of applications for ESP32

Development Board Overviews

If you have one of ESP32 development boards listed below, you can click on the link to learn more about its hardware.

Step 1. Set up the Toolchain

The toolchain is a set of programs for compiling code and building applications.

The quickest way to start development with ESP32 is by installing a prebuilt toolchain. Pick up your OS below and follow the provided instructions.

windows-logo linux-logo macos-logo
Windows Linux Mac OS

Note

This guide uses the directory ~/esp on Linux and macOS or %userprofile%\esp on Windows as an installation folder for ESP-IDF. You can use any directory, but you will need to adjust paths for the commands respectively. Keep in mind that ESP-IDF does not support spaces in paths.

Depending on your experience and preferences, you may want to customize your environment instead of using a prebuilt toolchain. To set up the system your own way go to Section Customized Setup of Toolchain (CMake).

Step 2. Get ESP-IDF

Besides the toolchain, you also need ESP32-specific API (software libraries and source code). They are provided by Espressif in ESP-IDF repository.

Get ESP-IDF in accordance with your operating system.

To get ESP-IDF, navigate to your installation directory and clone the repository with git clone.

Linux and MacOS

Open Terminal, and run the following commands:

cd ~/esp
git clone --recursive https://github.com/espressif/esp-idf.git

ESP-IDF will be downloaded into ~/esp/esp-idf.

Consult ESP-IDF Versions for information about which ESP-IDF version to use in a given situation.

Windows

Note

Previous versions of ESP-IDF used the MSYS2 bash terminal command line. The current cmake-based build system can run in the regular Windows Command Prompt which is used here.

If you use a bash-based terminal or PowerShell, please note that some command syntax will be different to what is shown below.

Open Command Prompt and run the following commands:

mkdir %userprofile%\esp
cd %userprofile%\esp
git clone --recursive https://github.com/espressif/esp-idf.git

ESP-IDF will be downloaded into %userprofile%\esp\esp-idf.

Consult ESP-IDF Versions for information about which ESP-IDF version to use in a given situation.

Note

This command will clone the master branch, which has the latest development (“bleeding edge”) version of ESP-IDF. It is fully functional and updated on weekly basis with the most recent features and bugfixes.

Note

GitHub’s “Download zip file” feature does not work with ESP-IDF, a git clone is required. As a fallback, Stable version can be installed without Git.

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-idf
git submodule update --init

Step 3. Set Environment Variables

Set the following environment variables on your computer, so that projects can be built:

  • Create IDF_PATH and assign it the path to the ESP-IDF directory.
  • Add to PATH the path to the tools directory inside the IDF_PATH directory.

These variables can be set temporarily (per session) or permanently. Please follow the instructions specific to Windows , Linux and MacOS in Section Add IDF_PATH & idf.py PATH to User Profile (CMake).

Step 4. Install the Required Python Packages

The python packages required by ESP-IDF are located in IDF_PATH/requirements.txt. You can install them by running:

python -m pip install --user -r $IDF_PATH/requirements.txt

Note

Please check the version of the Python interpreter that you will be using with ESP-IDF. For this, run the command python --version and depending on the result, you might want to use python2, python2.7 or similar instead of just python, e.g.:

python2.7 -m pip install --user -r $IDF_PATH/requirements.txt

Step 5. Start a Project

Now you are ready to prepare your application for ESP32. You can start with get-started/hello_world project from examples directory in IDF.

Copy get-started/hello_world to ~/esp directory:

Linux and MacOS

cd ~/esp
cp -r $IDF_PATH/examples/get-started/hello_world .

Windows

cd %userprofile%\esp
xcopy /e /i %IDF_PATH%\examples\get-started\hello_world hello_world

There is a range of example projects in the examples directory in ESP-IDF. You can copy any project in the same way as presented above and run it.

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 paths to either esp-idf or to projects.

Step 6. Connect Your Device

Now connect your ESP32 board to the computer and check under what serial port the board is visible.

Serial ports have the following patterns in their names:

  • Windows: names like COM1
  • Linux: starting with /dev/tty
  • macOS: starting with /dev/cu.

If you are not sure how to check the serial port name, please refer to Establish Serial Connection with ESP32 (CMake) for full details.

Note

Keep the port name handy as you will need it in the next steps.

Step 7. Configure

Navigate to your hello_world directory from Step 5. Start a Project and run the project configuration utility menuconfig.

Linux and MacOS

cd ~/esp/hello_world
idf.py menuconfig

If your default version of Python is 3.x, you may need to run python2 idf.py instead.

Windows

cd %userprofile%\esp\hello_world
idf.py menuconfig

The Python 2.7 installer will try to configure Windows to associate .py files with Python 2. If a separately 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

If you get an error idf.py not found, make sure that the PATH environment variable was set correctly in Step 3. Set Environment Variables. If there is no idf.py in tools, make sure you have the correct branch for the CMake preview as shown under Step 2. Get ESP-IDF.

If the previous steps have been done correctly, the following menu appears:

Project configuration - Home window

Project configuration - Home window

To navigate and use menuconfig, press the following keys:

  • Arrow keys for navigation
  • Enter to go into a submenu
  • Esc to go up one level or exit
  • ? to see a help screen. Enter key exits the help screen
  • Space, or Y and N keys to enable (Yes) and disable (No) configuration items with checkboxes “[*]
  • ? while highlighting a configuration item to display help about that item
  • / to find configuration items

Attention

If you use ESP32-DevKitC board with the ESP32-SOLO-1 module, enable single core mode (CONFIG_FREERTOS_UNICORE) in menuconfig before flashing examples.

Step 8. Build the Project

Build the project by running:

idf.py build

This command will compile the application and all ESP-IDF components, then it will generate the bootloader, partition table, and application binaries.

$ idf.py build
Running cmake in directory /path/to/hello_world/build
Executing "cmake -G Ninja --warn-uninitialized /path/to/hello_world"...
Warn about uninitialized values.
-- Found Git: /usr/bin/git (found version "2.17.0")
-- Building empty aws_iot component due to configuration
-- Component names: ...
-- Component paths: ...

... (more lines of build system output)

[527/527] Generating hello-world.bin
esptool.py v2.3.1

Project build complete. To flash, run this command:
../../../components/esptool_py/esptool/esptool.py -p (PORT) -b 921600 write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x10000 build/hello-world.bin  build 0x1000 build/bootloader/bootloader.bin 0x8000 build/partition_table/partition-table.bin
or run 'idf.py -p PORT flash'

If there are no errors, the build will finish by generating the firmware binary .bin file.

Step 9. Flash onto the Device

Flash the binaries that you just built onto your ESP32 board by running:

idf.py -p PORT [-b BAUD] flash

Replace PORT with your ESP32 board’s serial port name from Step 6. Connect Your Device.

You can also change the flasher baud rate by replacing BAUD with the baud rate you need. The default baud rate is 460800.

For more information on idf.py arguments, see idf.py.

Note

The option flash automatically builds and flashes the project, so running idf.py build is not necessary.

Running esptool.py in directory [...]/esp/hello_world
Executing "python [...]/esp-idf/components/esptool_py/esptool/esptool.py -b 460800 write_flash @flash_project_args"...
esptool.py -b 460800 write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x1000 bootloader/bootloader.bin 0x8000 partition_table/partition-table.bin 0x10000 hello-world.bin
esptool.py v2.3.1
Connecting....
Detecting chip type... ESP32
Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x0220
Compressed 22992 bytes to 13019...
Wrote 22992 bytes (13019 compressed) at 0x00001000 in 0.3 seconds (effective 558.9 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 82...
Wrote 3072 bytes (82 compressed) at 0x00008000 in 0.0 seconds (effective 5789.3 kbit/s)...
Hash of data verified.
Compressed 136672 bytes to 67544...
Wrote 136672 bytes (67544 compressed) at 0x00010000 in 1.9 seconds (effective 567.5 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...

If there are no issues by the end of the flash process, the module will be reset and the “hello_world” application will be running.

Step 10. Monitor

To check if “hello_world” is indeed running, type idf.py -p PORT monitor (Do not forget to replace PORT with your serial port name).

This command launches the IDF Monitor application:

$ idf.py -p /dev/ttyUSB0 monitor
Running idf_monitor in directory [...]/esp/hello_world/build
Executing "python [...]/esp-idf/tools/idf_monitor.py -b 115200 [...]/esp/hello_world/build/hello-world.elf"...
--- idf_monitor on /dev/ttyUSB0 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
ets Jun  8 2016 00:22:57

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun  8 2016 00:22:57
...

After startup and diagnostic logs scroll up, 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 IDF monitor use the shortcut Ctrl+].

If IDF monitor fails shortly after the upload, or, if instead of the messages above, you see random garbage similar to what is given below, your board is likely using a 26MHz crystal. Most development board designs use 40MHz, so ESP-IDF uses this frequency as a default value.

e���)(Xn@�y.!��(�PW+)��Hn9a؅/9�!�t5��P�~�k��e�ea�5�jA
~zY��Y(1�,1�� e���)(Xn@�y.!Dr�zY(�jpi�|�+z5Ymvp

If you have such a problem, do the following:

  1. Exit the monitor.
  2. Go back to menuconfig.
  3. Go to Component config –> ESP32-specific –> Main XTAL frequency, then change CONFIG_ESP32_XTAL_FREQ_SEL to 26MHz.
  4. After that, build and flash the application again.

Note

You can combine building, flashing and monitoring into one step by running:

idf.py -p PORT flash monitor

See also:

  • IDF Monitor for handy shortcuts and more details on using IDF monitor.
  • idf.py for a full reference of idf.py commands and options.

That’s all that you need to get started with ESP32!

Now you are ready to try some other examples, or go straight to developing your own applications.

Updating ESP-IDF

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 Step 2. Get ESP-IDF.

If downloading to a new path, remember to Add IDF_PATH & idf.py PATH to User Profile (CMake) so that the toolchain scripts can find ESP-IDF in its release specific location.

Another solution is to update only what has changed. The update procedure depends on the version of ESP-IDF you are using.