Get Started

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This document is intended to help you set up the software development environment for the hardware based on the ESP32-S2 chip by Espressif.

After that, a simple example will show you how to use ESP-IDF (Espressif IoT Development Framework) for menu configuration, then for building and flashing firmware onto an ESP32-S2 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-S2 is a system on a chip that integrates the following features:

  • Wi-Fi (2.4 GHz band)

  • Dual high performance cores

  • Ultra Low Power co-processor

  • Multiple peripherals

  • Built-in security hardware

  • USB OTG interface

Powered by 40 nm technology, ESP32-S2 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-S2 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-S2 board

  • USB cable - USB A / micro USB B

  • Computer running Windows, Linux, or macOS

Software:

  • Toolchain to compile code for ESP32-S2

  • Build tools - CMake and Ninja to build a full Application for ESP32-S2

  • ESP-IDF that essentially contains API (software libraries and source code) for ESP32-S2 and scripts to operate the Toolchain

  • Text editor to write programs (Projects) in C, e.g., Eclipse

Development of applications for ESP32-S2

Development of applications for ESP32-S2

Development Board Overviews

If you have one of ESP32-S2 development boards listed below, you can click on the link to learn more about its hardware.

Installation Step by Step

This is a detailed roadmap to walk you through the installation process.

Step 1. Install prerequisites

Some tools need to be installed on the computer before proceeding to the next steps. Follow the links below for the instructions for your OS:

windows-logo

linux-logo

macos-logo

Windows

Linux

Mac OS

Step 2. Get ESP-IDF

To build applications for the ESP32-S2, you need the software libraries provided by Espressif in ESP-IDF repository.

To get ESP-IDF, navigate to your installation directory and clone the repository with git clone, following instructions below specific to your operating system.

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.

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

In addition to installing the tools, ESP-IDF Tools Installer for Windows introduced in Step 1 can also download a copy of ESP-IDF.

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

If you wish to download ESP-IDF without the help of ESP-IDF Tools Installer, refer to these instructions.

Step 3. Set up the tools

Aside from the ESP-IDF, you also need to install the tools used by ESP-IDF, such as the compiler, debugger, Python packages, etc.

Windows

ESP-IDF Tools Installer for Windows introduced in Step 1 installs all the required tools.

If you want to install the tools without the help of ESP-IDF Tools Installer, open the Command Prompt and follow these steps:

cd %userprofile%\esp\esp-idf
install.bat

or with Windows PowerShell

cd ~/esp/esp-idf
./install.ps1

Linux and macOS

cd ~/esp/esp-idf
./install.sh

Customizing the tools installation path

The scripts introduced in this step install compilation tools required by ESP-IDF inside the user home directory: $HOME/.espressif on Linux and macOS, %USERPROFILE%\.espressif on Windows. If you wish to install the tools into a different directory, set the environment variable IDF_TOOLS_PATH before running the installation scripts. Make sure that your user account has sufficient permissions to read and write this path.

If changing the IDF_TOOLS_PATH, make sure it is set to the same value every time the Install script (install.bat, install.ps1 or install.sh) and an Export script (export.bat, export.ps1 or export.sh) are executed.

Step 4. Set up the environment variables

The installed tools are not yet added to the PATH environment variable. To make the tools usable from the command line, some environment variables must be set. ESP-IDF provides another script which does that.

Windows

ESP-IDF Tools Installer for Windows creates an “ESP-IDF Command Prompt” shortcut in the Start Menu. This shortcut opens the Command Prompt and sets up all the required environment variables. You can open this shortcut and proceed to the next step.

Alternatively, if you want to use ESP-IDF in an existing Command Prompt window, you can run:

%userprofile%\esp\esp-idf\export.bat

or with Windows PowerShell

.$HOME/esp/esp-idf/export.ps1

Linux and macOS

In the terminal where you are going to use ESP-IDF, run:

. $HOME/esp/esp-idf/export.sh

Note the space between the leading dot and the path!

You can also create an alias for the export script to your .profile or .bash_profile script. This way you can set up the environment in a new terminal window by typing get_idf:

alias get_idf='. $HOME/esp/esp-idf/export.sh'

Note that it is not recommended to source export.sh from the profile script directly. Doing so activates IDF virtual environment in every terminal session (even in those where IDF is not needed), defeating the purpose of the virtual environment and likely affecting other software.

Step 5. Start a Project

Now you are ready to prepare your application for ESP32-S2. 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-S2 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-S2 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, set ESP32-S2 chip as the target and run the project configuration utility menuconfig.

Linux and macOS

cd ~/esp/hello_world
idf.py set-target esp32s2
idf.py menuconfig

Windows

cd %userprofile%\esp\hello_world
idf.py set-target esp32s2
idf.py menuconfig

Setting the target with idf.py set-target {IDF_TARGET} should be done once, after opening a new project. If the project contains some existing builds and configuration, they will be cleared and initialized. The target may be saved in environment variable to skip this step at all. See Selecting the Target for additional information.

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

Project configuration - Home window

Project configuration - Home window

You are using this menu to set up project specific variables, e.g. Wi-Fi network name and password, the processor speed, etc. Setting up the project with menuconfig may be skipped for “hello_word”. This example will run with default configuration.

Note

The colors of the menu could be different in your terminal. You can change the appearance with the option --style. Please run idf.py menuconfig --help for further information.

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-S2 board by running:

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

Replace PORT with your ESP32-S2 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.

Encountered Issues While Flashing?

If you run the given command and see errors such as “Failed to connect”, there might be several reasons for this. One of the reasons might be issues encountered by esptool.py, the utility that is called by the build system to reset the chip, interact with the ROM bootloader, and flash firmware. One simple solution to try is manual reset described below, and if it does not help you can find more details about possible issues in Troubleshooting.

esptool.py resets ESP32-S2 automatically by asserting DTR and RTS control lines of the USB to serial converter chip, i.e., FTDI or CP210x (for more information, see Establish Serial Connection with ESP32-S2). The DTR and RTS control lines are in turn connected to GPIO0 and CHIP_PU (EN) pins of ESP32-S2, thus changes in the voltage levels of DTR and RTS will boot ESP32-S2 into Firmware Download mode. As an example, check the schematic for the ESP32 DevKitC development board.

In general, you should have no problems with the official esp-idf development boards. However, esptool.py is not able to reset your hardware automatically in the following cases:

  • Your hardware does not have the DTR and RTS lines connected to GPIO0 and CIHP_PU

  • The DTR and RTS lines are configured differently

  • There are no such serial control lines at all

Depending on the kind of hardware you have, it may also be possible to manually put your ESP32-S2 board into Firmware Download mode (reset).

  • For development boards produced by Espressif, this information can be found in the respective getting started guides or user guides. For example, to manually reset an esp-idf development board, hold down the Boot button (GPIO0) and press the EN button (CHIP_PU).

  • For other types of hardware, try pulling GPIO0 down.

Normal Operation

When flashing, you will see the output log similar to the following:

...
esptool.py --chip esp32s2 -p /dev/ttyUSB0 -b 460800 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 2MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x10000 hello-world.bin
esptool.py v3.0-dev
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP32-S2
Features: WiFi
Crystal is 40MHz
MAC: 18:fe:34:72:50:e3
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Compressed 3072 bytes to 103...
Writing at 0x00008000... (100 %)
Wrote 3072 bytes (103 compressed) at 0x00008000 in 0.0 seconds (effective 3851.6 kbit/s)...
Hash of data verified.
Compressed 22592 bytes to 13483...
Writing at 0x00001000... (100 %)
Wrote 22592 bytes (13483 compressed) at 0x00001000 in 0.3 seconds (effective 595.1 kbit/s)...
Hash of data verified.
Compressed 140048 bytes to 70298...
Writing at 0x00010000... (20 %)
Writing at 0x00014000... (40 %)
Writing at 0x00018000... (60 %)
Writing at 0x0001c000... (80 %)
Writing at 0x00020000... (100 %)
Wrote 140048 bytes (70298 compressed) at 0x00010000 in 1.7 seconds (effective 662.5 kbit/s)...
Hash of data verified.

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

If there are no issues by the end of the flash process, the board will reboot and start up the “hello_world” application.

If you’d like to use the Eclipse IDE instead of running idf.py, check out the Eclipse guide.

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...
This is esp32 chip with 2 CPU cores, WiFi/BT/BLE, silicon revision 1, 2MB external flash
Restarting in 9 seconds...
Restarting in 8 seconds...
Restarting in 7 seconds...

To exit IDF monitor use the shortcut Ctrl+].

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-S2!

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

Important

Some of examples do not support ESP32-S2 because required hardware is not included in ESP32-S2 so it cannot be supported.

If building an example, please check the README file for the Supported Targets table. If this is present including ESP32-S2 target, or the table does not exist at all, the example will work on ESP32-S2.

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.

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

After updating ESP-IDF, execute the Install script again, in case the new ESP-IDF version requires different versions of tools. See instructions at Step 3. Set up the tools.

Once the new tools are installed, update the environment using the Export script. See instructions at Step 4. Set up the environment variables.