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Getting started with the Espressif ESP32-WROOM-32SE - FreeRTOS
OverviewPrerequisitesGet started with ESP-IDF v3.3Get started with ESP-IDF v4.2Monitoring MQTT messages on the Amazon CloudAdditional information
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Getting started with the Espressif ESP32-WROOM-32SE

Important

This is an archived version of the FreeRTOS User Guide for use with FreeRTOS release 202012.00. For the latest version of this document, see the FreeRTOS User Guide.

Follow this tutorial to get started with the Espressif ESP32-WROOM-32SE. To purchase one from our partner on the Amazon Partner Device catalog, see ESP32-WROOM-32SE.

Note

Currently, the FreeRTOS port for ESP32-WROOM-32SE doesn't support the symmetric multiprocessing (SMP) feature.

Overview

This tutorial guides you through the following steps:

  1. Connect your board to a host machine

  2. Install software on your host machine to develop and debug embedded applications for your microcontroller board

  3. Cross-compile a FreeRTOS demo application to a binary image

  4. Load the application binary image to your board, and then run the application

  5. Monitor and debug the running application using a serial connection

Prerequisites

Before you get started with FreeRTOS on your Espressif board, you must set up your Amazon account and permissions.

Sign up for an Amazon Web Services account

If you do not have an Amazon Web Services account, use the following procedure to create one.

To sign up for Amazon Web Services

  1. Open http://www.amazonaws.cn/ and choose Sign Up.

  2. Follow the on-screen instructions.

Amazon sends you a confirmation email after the sign-up process is complete. At any time, you can view your current account activity and manage your account by going to http://www.amazonaws.cn/ and choosing My Account.

Secure IAM users

After you sign up for an Amazon Web Services account, safeguard your administrative user by turning on multi-factor authentication (MFA). For instructions, see Enable a virtual MFA device for an IAM user (console) in the IAM User Guide.

To give other users access to your Amazon Web Services account resources, create IAM users. To secure your IAM users, turn on MFA and only give the IAM users the permissions needed to perform their tasks.

For more information about creating and securing IAM users, see the following topics in the IAM User Guide:

To provide access, add permissions to your users, groups, or roles:

Note

The FreeRTOS 202012.00 release supports ESP-IDF v3.3. If you're using a later revision of FreeRTOS, follow the instructions specific to IDFv4.2 at Get started with the ESP-IDF v4.2.

Get started with ESP-IDF v3.3

This section shows you how to use ESP-IDF v3.3 on Espressif hardware. To use ESP-IDF v4.2, see Get started with ESP-IDF v4.2.

Set up the Espressif hardware

See the ESP32-DevKitC Getting Started Guide for information about setting up the ESP32-WROOM-32SE development board hardware.

Important

When you reach the Get Started section of the Espressif guide, stop and then follow the steps below.

Set up your development environment

To communicate with your board, you must download and install a toolchain.

Setting up the toolchain

Note

ESP-IDF v3.3 (the version that FreeRTOS uses) doesn't support the latest version of the ESP32 compiler. You must use the compiler that is compatible with version 3.3 of the ESP-IDF. See the previous links. To check the version of your compiler, run the following command.

xtensa-esp32-elf-gcc --version

To set up the toolchain, follow the instructions for your host machine's operating system:

Important

When you reach the "Get ESP-IDF" instructions under Next Steps, stop and return to the instructions on this page.

If you followed the "Get ESP-IDF" instructions under Next Steps, just now or on a previous occasion, you should clear the IDF_PATH environment variable from your system before you continue. This environment variable was automatically set if you followed the "Get ESP-IDF" instructions.

Install CMake

The CMake build system is required to build the FreeRTOS demo and test applications for this device. FreeRTOS supports versions 3.13 and later.

You can download the latest version of CMake from CMake.org. Source and binary distributions are available.

For more details about using CMake with FreeRTOS, see Using CMake with FreeRTOS.

Establish a serial connection

  1. To establish a serial connection between your host machine and the ESP32-WROOM-32SE, install the CP210x USB to UART Bridge VCP drivers. You can download these drivers from Silicon Labs.

  2. Follow the steps to Establish a Serial Connection with ESP32.

  3. After you establish a serial connection, make a note of the serial port for your board's connection. You need it when you build the demo.

Download and configure FreeRTOS

After you set up your environment, you can download FreeRTOS from GitHub. For instructions, see the README.md file on the GitHub website.

Important

The ATECC608A device has a one-time initialization that is locked onto the device the first time a project is run (during the call to C_InitToken). However, the FreeRTOS demo project and test project have different configurations. If the device is locked during the demo project configurations, not all tests in the test project will succeed.

  1. Configure the FreeRTOS Demo Project by following the steps in Configuring the FreeRTOS demos. Skip the last step To format your Amazon IoT credentials and follow the steps below instead.

  2. Microchip has provided several scripting tools to help with the setup of the ATECC608A parts. Navigate to the freertos/vendors/microchip/secure_elements/app/example_trust_chain_tool directory, and then open the README.md file.

  3. Follow the instructions in the README.md file to provision your device. The steps include the following:

    1. Create and register a certificate authority with Amazon

    2. Generate your keys on the ATECC608A and export the public key and device serial number

    3. Generate a certificate for the device and register that certificate with Amazon

  4. Load the CA certificate and device certificate onto the device by following the instructions for Developer-mode key provisioning.

Build, flash, and run the FreeRTOS demo project

You can use CMake to generate the build files, Make to build the application binary, and Espressif's IDF utility to flash your board.

Build FreeRTOS on Linux or MacOS (ESP-IDF v3.3)

If you're using Windows, you can skip to Build FreeRTOS on Windows (ESP-IDF v3.3).

Use CMake to generate the build files, and then use Make to build the application.

To generate the demo application's build files with CMake

  1. Navigate to the root of your FreeRTOS download directory.

  2. In a command line window, enter the following command to generate the build files.

    cmake -DVENDOR=espressif -DBOARD=esp32_plus_ecc608a_devkitc -DCOMPILER=xtensa-esp32 -S . -B your-build-directory
    Notes

    To build the application for debugging, add the -DCMAKE_BUILD_TYPE=Debug flag.

    To generate the test application build files, add the -DAFR_ENABLE_TESTS=1 flag.

    The code provided by Espressif uses the lightweight IP (lwIP) stack as the default networking stack. To use the FreeRTOS+TCP networking stack instead, add the –DAFR_ESP_FREERTOS_TCP flag to the CMake command.

    To add the lwIP dependency for non-vendor provided code, add the following lines to the CMake dependency file, CMakeLists.txt, for your custom Wi-Fi component.

    # Add a dependency on the bluetooth espressif component to the common component
set(COMPONENT_REQUIRES lwip)
To build the application with Make

  1. Navigate to the build directory.

  2. In a command line window, enter the following command to build the application with Make.

    make all -j4
    Note

    You must generate the build files with the cmake command every time you switch between the aws_demos project and the aws_tests project.

Build FreeRTOS on Windows (ESP-IDF v3.3)

On Windows, you must specify a build generator for CMake. Otherwise, CMake defaults to Visual Studio. Espressif officially recommends the Ninja build system because it works on Windows, Linux, and MacOS. You must run CMake commands in a native Windows environment like cmd or PowerShell. Running CMake commands in a virtual Linux environment, such as MSYS2 or WSL, isn't supported.

Use CMake to generate the build files, and then use Make to build the application.

To generate the demo application's build files with CMake

  1. Navigate to the root of your FreeRTOS download directory.

  2. In a command line window, enter the following command to generate the build files.

    cmake -DVENDOR=espressif -DBOARD=esp32_plus_ecc608a_devkitc -DCOMPILER=xtensa-esp32 -GNinja -S . -B your-build-directory
    Note

    To build the application for debugging, add the -DCMAKE_BUILD_TYPE=Debug flag.

    To generate the test application build files, add the -DAFR_ENABLE_TESTS=1 flag.

    The code provided by Espressif uses the lightweight IP (lwIP) stack as the default networking stack. To use the FreeRTOS+TCP networking stack instead, add the –DAFR_ESP_FREERTOS_TCP flag to the CMake command.

    To add the lwIP dependency for non-vendor provided code, add the following lines to the CMake dependency file, CMakeLists.txt, for your custom Wi-Fi component.

    # Add a dependency on the bluetooth espressif component to the common component
set(COMPONENT_REQUIRES lwip)
To build the application

  1. Navigate to the build directory.

  2. In a command line window, enter the following command to invoke Ninja to build the application.

    ninja

    Or, use the generic CMake interface to build the application.

    cmake --build your-build-directory
    Note

    You must generate the build files with the cmake command every time you switch between the aws_demos project and the aws_tests project.

Flash and run FreeRTOS (ESP-IDF v3.3)

Use Espressif's IDF utility (freertos/vendors/espressif/esp-idf/tools/idf.py) to flash your board, run the application, and see logs.

To erase the board's flash, navigate to the freertos directory and enter the following command.

./vendors/espressif/esp-idf/tools/idf.py erase_flash -B build-directory

To flash the application binary to your board, use make.

make flash

You can also use the IDF script to flash your board.

./vendors/espressif/esp-idf/tools/idf.py flash -B build-directory

Use the following command to view logs:

./vendors/espressif/esp-idf/tools/idf.py monitor -p /dev/ttyUSB1 -B build-directory
Tip

You can also combine these commands.

./vendors/espressif/esp-idf/tools/idf.py erase_flash flash monitor -p /dev/ttyUSB1 -B build-directory

Get started with ESP-IDF v4.2

This section shows you how to use ESP-IDF v4.2 on Espressif hardware. To use ESP-IDF v3.3, see Get started with ESP-IDF v3.3.

Note

The Linux commands in this tutorial require that you use the Bash shell.

Set up the Espressif hardware

For information about setting up the ESP32-WROOM-32SE development board hardware, see the ESP32-DevKitC V4 Getting Started Guide.

Important

When you reach the Get Started section of the Espressif guides, stop, and then follow the steps below.

Set up your development environment

To communicate with your board, you need to download and install a toolchain.

Set up the toolchain

To set up the toolchain, follow the instructions for your host machine's operating system:

Important

When you reach the "Get ESP-IDF" instructions under Next Steps, stop, and then return to the instructions on this page.

Complete the installation (Linux / Mac)

The ESP-IDF Windows installer installs all of the necessary tools. The Linux and MAC OSX platforms require an additional step in order to complete the installation.

Open a command line window, navigate to the FreeRTOS download directory, and then run the following script to download and install the espressif toolchain for your platform.

vendors/espressif/esp-idf/install.sh

Next, add the ESP-IDF toolchain tools to your terminal's path with the following command.

source vendors/espressif/esp-idf/export.sh

Establish a serial connection

  1. To establish a serial connection between your host machine and the ESP32-WROOM-32SE, install the CP210x USB to UART Bridge VCP drivers. You can download these drivers from Silicon Labs.

  2. Follow the steps to Establish a Serial Connection with ESP32.

  3. After you establish a serial connection, make a note of the serial port for your board's connection. You need it when you build the demo.

Download and configure FreeRTOS

After you set up your environment, you can download FreeRTOS from GitHub. For instructions, see the README.md file on the GitHub website.

Important

The ATECC608A device has a one-time initialization that is locked onto the device the first time a project is run (during the call to C_InitToken). However, the FreeRTOS demo project and test project have different configurations. If the device is locked during the demo project configurations, not all tests in the test project will succeed.

  1. Configure the FreeRTOS Demo Project by following the steps in Configuring the FreeRTOS demos. When you get to the last step To format your Amazon IoT credentials STOP and follow the steps below instead.

  2. Microchip has provided several scripting tools to help with the setup of the ATECC608A parts. Navigate to the freertos/vendors/microchip/secure_elements/app/example_trust_chain_tool directory, and open the README.md file.

  3. Follow the instructions in the README.md file to provision your device. The steps include the following:

    1. Create and register a certificate authority with Amazon

    2. Generate your keys on the ATECC608A and export the public key and device serial number

    3. Generate a certificate for the device and register that certificate with Amazon

  4. Load the CA certificate and device certificate onto the device by following the instructions for Developer-mode key provisioning.

Build, flash, and run the FreeRTOS demo project using the idf.py script

You can use Espressif's IDF utility to generate the build files, build the application binary, and flash your board.

Build and flash FreeRTOS on Windows, Linux, and MacOS (ESP-IDF v4.2)

Use the idf.py script to build the project and flash the binaries onto your device.

Note

Some setups might require that you use the port option "-p port-name" with idf.py to specify the correct port, as in the following example.

idf.py -p /dev/cu.usbserial-00101301B flash
To build and flash the project

  1. Navigate to the root of your FreeRTOS download directory.

  2. In a command line window, enter the following command to add the ESP-IDF tools to your terminal's PATH:

    Windows

    vendors\espressif\esp-idf\export.bat

    Linux / MacOS

    source vendors/espressif/esp-idf/export.sh

  3. Configure cmake in the build directory and build the firmware image with the following command.

    idf.py -DVENDOR=espressif -DBOARD=esp32_ecc608a_devkitc -DCOMPILER=xtensa-esp32 build

    You should see output like this following example.

    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 generate the firmware binary .bin files.

  4. Erase your development board's flash memory with the following command.

    idf.py erase_flash

  5. Use the idf.py script to flash the application binary to your board.

    idf.py flash

  6. Monitor the output from your board's serial port with the following command.

    idf.py monitor
Note

You can combine these commands as in the following example.

idf.py erase_flash flash monitor
Note

For certain host machine setups, you must specify the port when you flash the board as in the following example.

idf.py erase_flash flash monitor -p /dev/ttyUSB1

Build and Flash FreeRTOS with CMake

Besides using the idf.py script provided by the IDF SDK to build and run your code, you can also build the project with CMake. Currently it supports Unix Makefile and the Ninja build system.

To build and flash the project

  1. In a command line window, navigate to the root of your FreeRTOS download directory.

  2. Run the following script to add the ESP-IDF tools to your shell's PATH.

    Windows

    vendors\espressif\esp-idf\export.bat

    Linux / MacOS

    source vendors/espressif/esp-idf/export.sh

  3. Enter the following command to generate the build files.

    With Unix Makefiles 

    cmake -DVENDOR=espressif -DBOARD=esp32_plus_ecc608a_devkitc -DCOMPILER=xtensa-esp32 -S . -B ./YOUR_BUILD_DIRECTORY -DAFR_ENABLE_ALL_MODULES=1 -DAFR_ENABLE_TESTS=0

    With Ninja

    cmake -DVENDOR=espressif -DBOARD=esp32_plus_ecc608a_devkitc -DCOMPILER=xtensa-esp32 -S . -B ./YOUR_BUILD_DIRECTORY -DAFR_ENABLE_ALL_MODULES=1 -DAFR_ENABLE_TESTS=0 -GNinja

  4. Erase the flash and then flash the board.

    With Unix Makefiles 

    make -C ./YOUR_BUILD_DIRECTORY erase_flash
    make -C ./YOUR_BUILD_DIRECTORY flash

    With Ninja

    ninja -C ./YOUR_BUILD_DIRECTORY erase_flash
    ninja -C ./YOUR_BUILD_DIRECTORY flash

Monitoring MQTT messages on the Amazon Cloud

You can use the MQTT client in the Amazon IoT console to monitor the messages that your device sends to the Amazon Cloud.

To subscribe to the MQTT topic with the Amazon IoT MQTT client

  1. Sign in to the Amazon IoT console.

  2. In the navigation pane, choose Test to open the MQTT client.

  3. In Subscription topic, enter your-thing-name/example/topic, and then choose Subscribe to topic.

Additional information

For additional information on using and troubleshooting Espressif ESP32 boards, see the following topics: