Getting started with the Espressif ESP32-DevKitC and the ESP-WROVER-KIT
Follow this tutorial to get started with the Espressif ESP32-DevKitC equipped with ESP32-WROOM-32, ESP32-SOLO-1, or ESP-WROVER modules and the ESP-WROVER-KIT-VB. To purchase one from our partner on the AWS Partner Device catalog, use the following links:
These versions of development boards are supported on FreeRTOS.
For more information about the latest versions of these boards, see
ESP32-DevKitC V4
Currently, the FreeRTOS port for ESP32-WROVER-KIT and ESP DevKitC doesn't support the Symmetric multiprocessing (SMP) feature.
Overview
This tutorial guides you through the following steps:
-
Connecting your board to a host machine
-
Installing software on the host machine for developing and debugging embedded applications for your microcontroller board
-
Cross compiling a FreeRTOS demo application to a binary image
-
Loading the application binary image to your board, and then running the application
-
Interacting with the application running on your board across a serial connection, for monitoring and debugging purposes
Prerequisites
Before you get started with FreeRTOS on your Espressif board, you must set up your AWS account and permissions.
To create an account, see Create and Activate an AWS
Account
To add an AWS Identity and Access Management (IAM) user to your account, see the IAM User Guide. To grant your IAM user account access to AWS IoT and FreeRTOS, attach the following IAM policies to your IAM user account:
-
AmazonFreeRTOSFullAccess
Allows full access to all of your IAM user's FreeRTOS resources (freertos:*).
-
AWSIoTFullAccess
Allows full access to all of your IAM user's AWS IoT resources (iot:*).
To attach the AmazonFreeRTOSFullAccess policy to your IAM user
-
Navigate to the IAM console
. -
In the navigation pane, choose Users.
-
Enter your user name in the search text box, and then choose it from the list.
-
Choose Add permissions.
-
Choose Attach existing policies directly.
-
In the search box, enter
AmazonFreeRTOSFullAccess
, choose it from the list, and then choose Next: Review. -
Choose Add permissions.
To attach the AWSIoTFullAccess policy to your IAM user
-
Navigate to the IAM console
. -
In the navigation pane, choose Users.
-
Enter your user name in the search text box, and then choose it from the list.
-
Choose Add permissions.
-
Choose Attach existing policies directly.
-
In the search box, enter
AWSIoTFullAccess
, choose it from the list, and then choose Next: Review. -
Choose Add permissions.
For more information about IAM and user accounts, see the IAM User Guide.
For more information about policies, see Permissions and policies in IAM.
The FreeRTOS 202012.00 release supports ESP-IDF v3.3. If you're using a later version 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 the ESP-IDF v4.2.
Set up the Espressif hardware
For more information about setting up the ESP32-DevKitC development board hardware,
see the ESP32-DevKitC
V4 Getting Started Guide
For information about setting up the ESP-WROVER-KIT development board hardware. see
the
ESP-WROVER-KIT V4.1 Getting Started Guide
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 must download and install a toolchain.
Setting up the toolchain
ESP-IDF v3.3 doesn't support the latest version of the ESP32 compiler. If you have already installed the latest version of the ESP32 compiler, you should uninstall it and use the compatible version of the compiler that is included in the toolchain installation. See the links in this section. To check the version of your compiler, run the following command.
xtensa-esp32-elf-gcc --version
To set up the toolchain, follow these instructions for your host machine's operating system:
When you reach the "Get ESP-IDF" instructions under Next Steps, stop, and then 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
For more details about using CMake with FreeRTOS, see Using CMake with FreeRTOS.
Establish a serial connection
To establish a serial connection between your host machine and the ESP32-DevKitC,
you must install CP210x USB to UART Bridge VCP drivers. You can download these
drivers from
Silicon Labs
To establish a serial connection between your host machine and the ESP32-WROVER-KIT,
you must install some
FTDI virtual COM port drivers. You can download these drivers from FTDI
For more information, see
Establish Serial Connection with ESP32
Download and configure FreeRTOS
After you set up your environment, you can download FreeRTOS from GitHub
Configure the FreeRTOS demo applications
-
If you're running macOS or Linux, open a terminal prompt. If you're running Windows, open the
mingw32.exe
. MinGWis a minimalist development environment for native Microsoft Windows applications. -
To verify that you have Python 2.7.10 or later installed, run
python --version
The version installed is displayed. If you don't have Python 2.7.10 or later installed, you can install it from the Python
website. -
You need the AWS Command Line Interface (AWS CLI) to run AWS IoT commands. If you're running Windows, use the easy_install awscli to install the AWS CLI in the mingw32 environment.
If you're running macOS or Linux, see Installing the AWS CLI.
-
Run aws configure and configure the AWS CLI with your AWS access key ID, secret access key, and AWS Region. For more information, see Configuring the AWS CLI.
-
Use the following command to install the AWS SDK for Python (boto3):
-
On Windows, in the mingw32 environment, run
easy_install boto3
-
On macOS or Linux, run
pip install tornado nose --user
and then run
pip install boto3 --user
-
FreeRTOS includes the SetupAWS.py
script to make it easier to set up your Espressif
board to connect to AWS IoT. To configure the script, open
and set the following attributes:
freertos
/tools/aws_config_quick_start/configure.json
afr_source_dir
-
The complete path to the
freertos
directory on your computer. Make sure that you use forward slashes to specify this path. thing_name
-
The name that you want to assign to the AWS IoT thing that represents your board.
wifi_ssid
-
The SSID of your Wi-Fi network.
wifi_password
-
The password for your Wi-Fi network.
wifi_security
-
The security type for your Wi-Fi network.
The following are valid security types:
-
eWiFiSecurityOpen
(Open, no security) -
eWiFiSecurityWEP
(WEP security) -
eWiFiSecurityWPA
(WPA security) -
eWiFiSecurityWPA2
(WPA2 security)
-
To run the configuration script
-
If you're running macOS or Linux, open a terminal prompt. If you're running Windows, open
mingw32.exe
. -
Navigate to the
directory and runfreertos
/tools/aws_config_quick_startpython SetupAWS.py setup
The script does the following:
-
Creates an IoT thing, certificate, and policy
-
Attaches the IoT policy to the certificate and the certificate to the AWS IoT thing
-
Populates the
aws_clientcredential.h
file with your AWS IoT endpoint, Wi-Fi SSID, and credentials -
Formats your certificate and private key and writes them to the
aws_clientcredential_keys.h
header fileNote The certificate is hardcoded for demonstration purposes only. Production-level applications should store these files in a secure location.
For more information about SetupAWS.py
, see the README.md
in the
directory.
freertos
/tools/aws_config_quick_start
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 and MacOS (ESP-IDF v3.3)
If you're using Windows, see 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
-
Change directories to the root of your FreeRTOS download directory.
-
Use the following command to generate the build files.
cmake -DVENDOR=espressif -DBOARD=esp32_wrover_kit -DCOMPILER=xtensa-esp32 -S . -B
your-build-directory
Note If you want to build the application for debugging, add the
-DCMAKE_BUILD_TYPE=Debug
flag to this command.If you want 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
-
Change directories to the
build
directory. -
Use 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 theaws_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, like MSYS2 or WSL, is not 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
-
Change directories to the root of your FreeRTOS download directory.
-
Use the following command to generate the build files.
cmake -DVENDOR=espressif -DBOARD=esp32_wrover_kit -DCOMPILER=xtensa-esp32 -GNinja -S . -B
build-directory
Note If you want to build the application for debugging, add the
-DCMAKE_BUILD_TYPE=Debug
flag to this command.If you want 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
-
Change directories to the
build
directory. -
Invoke Ninja to build the application.
ninja
Or, use the generic CMake interface to build the application.
cmake --build
build-directory
Note You must generate the build files with the cmake command every time you switch between the
aws_demos
project and theaws_tests
project.
Flash and run FreeRTOS (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 the ESP-IDF v4.2.
Use Espressif's IDF utility
(
)
to flash your board, run the application, and see logs.
freertos
/vendors/espressif/esp-idf/tools/idf.py
To erase the board's flash, go to the
directory
and use the following command.
freertos
./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
To monitor:
./vendors/espressif/esp-idf/tools/idf.py monitor -p /dev/ttyUSB1 -B
build-directory
You can combine these commands. For example:
./vendors/espressif/esp-idf/tools/idf.py erase_flash flash monitor -p /dev/ttyUSB1 -B
build-directory
Get started with the 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.
Set up the Espressif hardware
For information about setting up the ESP32-DevKitC development board hardware, see
the
ESP32-DevKitC V4 Getting Started Guide
For information about setting up the ESP-WROVER-KIT development board hardware, see
the
ESP-WROVER-KIT V4.1 Getting Started Guide
When you reach the Get Started section of the Espressif guides, stop, and then return to the instructions on this page.
Set up your development environment
To communicate with your board, you must download and install a toolchain.
Setting up the toolchain
To set up the toolchain, follow these instructions for your host machine's operating system:
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 / MacOS)
The ESP-IDF Windows installer installs all of the neceesary tools. The Linux and MacOS platforms require an additional step 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
-
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
To establish a serial connection between your host machine and the ESP32-DevKitC,
you must install the
CP210x USB to UART Bridge VCP drivers. You can download these drivers from
Silicon Labs
To establish a serial connection between your host machine and the ESP32-WROVER-KIT,
you must install the
FTDI virtual COM port driver. You can download this driver from FTDI
For more information, see
Establish Serial Connection with ESP32
Download and configure FreeRTOS
After you set up your environment, you can download FreeRTOS from GitHub
Configure the FreeRTOS demo applications
-
If you're running macOS or Linux, open a terminal prompt. If you're running Windows, open mingw32.exe. ( MinGW
is a minimalist development environment for native Microsoft Windows applications.) -
To verify that you have Python3 installed, run
python --version
The version installed is displayed. If you don't have Python 3.0.1 or later installed, you can install it from the Python
website. -
You need the AWS Command Line Interface (AWS CLI) to run AWS IoT commands. If you're running Windows, use the easy_install awscli to install the AWS CLI in the mingw32 environment.
If you're running macOS or Linux, see Installing the AWS CLI.
-
Run
aws configure
and configure the AWS CLI with your AWS access key ID, secret access key, and default AWS Region. For more information, see Configuring the AWS CLI.
-
Use the following command to install the AWS SDK for Python (boto3):
-
On Windows, in the mingw32 environment, run
easy_install boto3
-
On macOS or Linux, run
pip install tornado nose --user
and then run
pip install boto3 --user
-
FreeRTOS includes the SetupAWS.py
script to make it easier to set up your Espressif
board to connect to AWS IoT. To configure the script, open
and
set the following attributes:
freertos
/tools/aws_config_quick_start/configure.json
afr_source_dir
-
The complete path to the
freertos
directory on your computer. Make sure that you use forward slashes to specify this path. thing_name
-
The name that you want to assign to the AWS IoT thing that represents your board.
wifi_ssid
-
The SSID of your Wi-Fi network.
wifi_password
-
The password for your Wi-Fi network.
wifi_security
-
The security type for your Wi-Fi network.
The following are valid security types:
-
eWiFiSecurityOpen
(Open, no security) -
eWiFiSecurityWEP
(WEP security) -
eWiFiSecurityWPA
(WPA security) -
eWiFiSecurityWPA2
(WPA2 security)
-
To run the configuration script
-
If you're running macOS or Linux, open a terminal prompt. If you're running Windows, open the
mingw32.exe
file. -
Navigate to the
directory and runfreertos
/tools/aws_config_quick_startpython SetupAWS.py setup
The script does the following:
-
Creates an IoT thing, certificate, and policy
-
Attaches the IoT policy to the certificate and the certificate to the AWS IoT thing
-
Populates the
aws_clientcredential.h
file with your AWS IoT endpoint, Wi-Fi SSID, and credentials -
Formats your certificate and private key and writes them to the
aws_clientcredential_keys.h
header fileNote The certificate is hardcoded for demonstration purposes only. Production-level applications should store these files in a secure location.
For more information about SetupAWS.py
, see the
README.md
in the
directory.
freertos
/tools/aws_config_quick_start
Build, flash, and run the FreeRTOS demo project using the idy.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.
Some setups might require that you use the port option
"-p
with port-name
"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
-
Navigate to the root of your FreeRTOS download directory.
-
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
-
Configure cmake in the
build
directory and build the firmware image with the following command.idf.py -DVENDOR=espressif -DBOARD=esp32_wrover_kit -DCOMPILER=xtensa-esp32 build
You should see output like the following.
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.
-
Erase your development board's flash memory with the following command.
idf.py erase_flash
-
Use the
idf.py
script to flash the application binary to your board.idf.py flash
-
Monitor the output from your board's serial port with the following command.
idf.py monitor
You can combine these commands such as in the following example.
idf.py erase_flash flash monitor
For certain host machine setups, you must specify the port when you flash the board such as in the following example.
idf.py erase_flash flash monitor -p
/dev/ttyUSB1
Build and Flash FreeRTOS with CMake
In addition to 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 either Unix
Makefiles or the
Ninja build system.
To build and flash the project
-
In a command line window, navigate to the root of your FreeRTOS download directory.
-
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
-
Enter the following command to generate the build files.
With Unix Makefiles
cmake -DVENDOR=espressif -DBOARD=esp32_wrover_kit -DCOMPILER=xtensa-esp32 -S . -B
./YOUR_BUILD_DIRECTORY
-DAFR_ENABLE_ALL_MODULES=1 -DAFR_ENABLE_TESTS=0With Ninja
cmake -DVENDOR=espressif -DBOARD=esp32_wrover_kit -DCOMPILER=xtensa-esp32 -S . -B
./YOUR_BUILD_DIRECTORY
-DAFR_ENABLE_ALL_MODULES=1 -DAFR_ENABLE_TESTS=0 -GNinja -
Erase the flash and then flash the board.
With Unix Makefiles
make -C
./YOUR_BUILD_DIRECTORY
erase_flashmake -C
./YOUR_BUILD_DIRECTORY
flashWith Ninja
ninja -C
./YOUR_BUILD_DIRECTORY
erase_flashninja -C
./YOUR_BUILD_DIRECTORY
flash
Monitoring MQTT messages on the cloud
You can use the MQTT client in the AWS IoT console to monitor the messages that your device sends to the AWS Cloud.
To subscribe to the MQTT topic with the AWS IoT MQTT client
-
Navigate to the AWS IoT console
. -
In the navigation pane, choose Test to open the MQTT client.
-
In Subscription topic, enter
, and then choose Subscribe to topic.your-thing-name
/example/topic
Run the Bluetooth Low Energy demos
FreeRTOS supports Bluetooth Low Energy connectivity.
To run the FreeRTOS demo project across Bluetooth Low Energy, you must run the FreeRTOS Bluetooth Low Energy Mobile SDK Demo Application on an iOS or Android mobile device.
To set up the FreeRTOS Bluetooth Low Energy mobile SDK demo application
-
Follow the instructions in Mobile SDKs for FreeRTOS Bluetooth Devices to download and install the SDK for your mobile platform on your host computer.
-
Follow the instructions in FreeRTOS Bluetooth Low Energy Mobile SDK Demo Application to set up the demo mobile application on your mobile device.
For instructions about how to run the MQTT over Bluetooth Low Energy demo on your board, see the MQTT over Bluetooth Low Energy Demo Application.
For instructions about how to run the Wi-Fi provisioning demo on your board, see the Wi-Fi Provisioning Demo Application.
Using FreeRTOS in your own CMake project for ESP32
If you want to consume FreeRTOS in your own CMake project, you can set it up as a
subdirectory and build it
together with your application. First, get a copy of FreeRTOS either from GitHub
git submodule add -b release https://github.com/aws/amazon-freertos.git freertos
If a later version is released, you can update your local copy with these commands.
# Pull the latest changes from the remote tracking branch. git submodule update --remote -- amazon-freertos
# Commit the submodule change because it is pointing to a different revision now. git add amazon-freertos
git commit -m "Update FreeRTOS to a new release"
If your project has the following directory structure:
- freertos (the copy that you obtained from GitHub or the AWS IoT console) - src - main.c (your application code) - CMakeLists.txt
Then the following is an example of the top-level CMakeLists.txt
file that can be used
to build your application together with FreeRTOS.
cmake_minimum_required(VERSION 3.13) project(freertos_examples) add_executable(my_app src/main.c) # Tell IDF build to link against this target. set(IDF_PROJECT_EXECUTABLE my_app) # Add FreeRTOS as a subdirectory. AFR_BOARD tells which board to target. set(AFR_BOARD espressif.esp32_devkitc CACHE INTERNAL "") add_subdirectory(freertos) # Link against the mqtt library so that we can use it. Dependencies are transitively # linked. target_link_libraries(my_app PRIVATE AFR::mqtt)
To build the project, run the following CMake commands. Make sure the ESP32 compiler is in the PATH environment variable.
cmake -S . -B
build-directory
-DCMAKE_TOOLCHAIN_FILE=freertos/tools/cmake/toolchains/xtensa-esp32.cmake -GNinja
cmake --build build
To flash the application to your board, run the following command.
cmake --build
build-directory
--target flash
Using components from FreeRTOS
After running CMake, you can find all available components in the summary output. It should look something like the following example.
====================Configuration for FreeRTOS==================== Version: 201910.00 Git version: 201910.00-388-gcb3612cb7 Target microcontroller: vendor: Espressif board: ESP32-DevKitC description: Development board produced by Espressif that comes in two variants either with ESP-WROOM-32 or ESP32-WROVER module family: ESP32 data ram size: 520KB program memory size: 4MB Host platform: OS: Linux-4.15.0-66-generic Toolchain: xtensa-esp32 Toolchain path: /opt/xtensa-esp32-elf CMake generator: Ninja FreeRTOS modules: Modules to build: ble, ble_hal, ble_wifi_provisioning, common, crypto, defender, dev_mode_key_provisioning, freertos_plus_tcp, greengrass, https, kernel, mqtt, ota, pkcs11, pkcs11_implementation, platform, secure_sockets, serializer, shadow, tls, wifi Enabled by user: ble, ble_hal, ble_wifi_provisioning, defender, greengrass, https, mqtt, ota, pkcs11, pkcs11_implementation, platform, secure_sockets, shadow, wifi Enabled by dependency: common, crypto, demo_base, dev_mode_key_provisioning, freertos, freertos_plus_tcp, kernel, pkcs11_mbedtls, secure_sockets_freertos_plus_tcp, serializer, tls, utils 3rdparty dependencies: http_parser, jsmn, mbedtls, pkcs11, tinycbor Available demos: demo_ble, demo_ble_numeric_comparison, demo_defender, demo_greengrass_connectivity, demo_https, demo_mqtt, demo_ota, demo_shadow, demo_tcp, demo_wifi_provisioning Available tests: =========================================================================
You can reference any components from the Modules to build
list. To link them into your
application, put the AFR::
namespace in front of the name, for example, AFR::mqtt
,
AFR::ota
, and so on.
Add custom components to ESP-IDF
You can add more components to the ESP-IDF build environment. For example, assuming
you want to add a
component called example_component
, and your project looks like this
- freertos - components - example_component - include - example_component.h - src - example_component.c - CMakeLists.txt - src - main.c - CMakeLists.txt
then the following is an example of the CMakeLists.txt
file for your
component.
# include paths of this components. set(COMPONENT_ADD_INCLUDEDIRS include) # source files of this components. set(COMPONENT_SRCDIRS src) # Alternatively, use COMPONENT_SRCS to specify source files explicitly # set(COMPONENT_SRCS src/
example_component.c
) # add this components, this will define a CMake library target. register_component()
You can also specify dependencies using the standard CMake function
target_link_libraries
. Note that the target name for your component
is stored in the variable COMPONENT_TARGET
, defined by the ESP-IDF.
# add this component, this will define a CMake library target. register_component() # standard CMake function can be used to specify dependencies. ${COMPONENT_TARGET} is defined # from esp-idf when you call register_component, by default it's idf_component_<folder_name>. target_link_libraries(${COMPONENT_TARGET} PRIVATE AFR::mqtt)
For ESP components, this is done by setting two variables COMPONENT_REQUIRES
and
COMPONENT_PRIV_REQUIRES
. See
Build System (CMake)
# If the dependencies are from ESP-IDF, use these 2 variables. Note these need to be # set before calling register_component(). set(COMPONENT_REQUIRES log) set(COMPONENT_PRIV_REQUIRES lwip)
Then, in the top level CMakeLists.txt
file, you tell ESP-IDF where to find these
components. Add the following lines anywhere before add_subdirectory(freertos)
.
# Add some extra components. IDF_EXTRA_COMPONENT_DIRS is a variable used by ESP-IDF # to collect extra components. get_filename_component( EXTRA_COMPONENT_DIRS "components/
example_component
" ABSOLUTE ) list(APPEND IDF_EXTRA_COMPONENT_DIRS ${EXTRA_COMPONENT_DIRS})
This component is now automatically linked to your application code by default. You should be able to include its header files and call the functions it defines.
Override the configurations for FreeRTOS
There's currently no well-defined approach to redefining the configs outside of the
FreeRTOS source tree.
By default, CMake will look for the
and freertos
/vendors/espressif/boards/esp32/aws_demos/config_files/
directories. However, you can
use a workaround to tell the compiler to search other directories first. For example,
you can add another
folder for FreeRTOS configurations.
freertos
/demos/include/
- freertos - freertos-configs - aws_clientcredential.h - aws_clientcredential_keys.h - iot_mqtt_agent_config.h - iot_config.h - components - src - CMakeLists.txt
The files under freertos-configs
are copied from the
and freertos
/vendors/espressif/boards/esp32/aws_demos/config_files/
directories. Then, in your top
level freertos
/demos/include/CMakeLists.txt
file, add this line before add_subdirectory(freertos)
so that the compiler will search this directory first.
include_directories(BEFORE freertos-configs)
Providing your own sdkconfig for ESP-IDF
In case you want to provide your own sdkconfig.default
, you can set the CMake variable
IDF_SDKCONFIG_DEFAULTS
, from the command line:
cmake -S . -B
build-directory
-DIDF_SDKCONFIG_DEFAULTS=path_to_your_sdkconfig_defaults
-DCMAKE_TOOLCHAIN_FILE=freertos/tools/cmake/toolchains/xtensa-esp32.cmake -GNinja
If you don’t specify a location for your own sdkconfig.default
file, FreeRTOS
will use the default file located at
.
freertos
/vendors/espressif/boards/esp32/aws_demos/sdkconfig.defaults
Summary
If you have a project with a component called example_component
, and you want to override some
configurations, here's a complete example of the top level CMakeLists.txt
file.
cmake_minimum_required(VERSION 3.13) project(freertos_examples) add_executable(my_app src/main.c) # Tell IDF build to link against this target. set(IDF_PROJECT_EXECUTABLE my_app) # Add some extra components. IDF_EXTRA_COMPONENT_DIRS is a variable used by ESP-IDF # to collect extra components. get_filename_component( EXTRA_COMPONENT_DIRS "components/
example_component
" ABSOLUTE ) list(APPEND IDF_EXTRA_COMPONENT_DIRS ${EXTRA_COMPONENT_DIRS}) # Override the configurations for FreeRTOS. include_directories(BEFOREfreertos
-configs) # Add FreeRTOS as a subdirectory. AFR_BOARD tells which board to target. set(AFR_BOARD espressif.esp32_devkitc CACHE INTERNAL "") add_subdirectory(freertos
) # Link against the mqtt library so that we can use it. Dependencies are transitively # linked. target_link_libraries(my_app PRIVATE AFR::mqtt)
Troubleshooting
-
If you're running macOS and the operating system doesn't recognize your ESP-WROVER-KIT, make sure you don't have the D2XX drivers installed. To uninstall them, follow the instructions in the FTDI Drivers Installation Guide for macOS X
. -
The monitor utility provided by ESP-IDF (and invoked using make monitor) helps you decode addresses. For this reason, it can help you get some meaningful backtraces in the event the application stops working. For more information, see Automatic Address Decoding
on the Espressif website. -
It's also possible to enable GDBstub for communication with gdb without requiring any special JTAG hardware. For more information, see Launching GDB with GDBStub
on the Espressif website. -
For information about setting up an OpenOCD-based environment if JTAG hardware-based debugging is required, see JTAG Debugging
on the Espressif website. -
If
pyserial
can't be installed usingpip
on macOS, download it from the pyserial website. -
If the board resets continuously, try erasing the flash by entering the following command on the terminal.
make erase_flash
-
If you see errors when you run
idf_monitor.py
, use Python 2.7. -
Required libraries from ESP-IDF are included in FreeRTOS, so there is no need to download them externally. If the
IDF_PATH
environment variable is set, we recommend that you clear it before you build FreeRTOS. -
On Windows, it can take 3-4 minutes for the project to build. You can use the
-j4
switch on the make command to reduce the build time:make flash monitor -j4
-
If your device has trouble connecting to AWS IoT, open the
aws_clientcredential.h
file, and verify that the configuration variables are properly defined in the file.clientcredentialMQTT_BROKER_ENDPOINT[]
should look like
.1234567890123
-ats.iot.us-east-1
.amazonaws.com -
If you're following the steps in Using FreeRTOS in your own CMake project for ESP32 and you see undefined reference errors from the linker, it's usually because of missing dependent libraries or demos. To add them, update the
CMakeLists.txt
file (under the root directory) using the standard CMake functiontarget_link_libraries
.
-
ESP-IDF v4.2 supports the use of the xtensa-esp32-elf-gcc 8.2.0. toolchain. If you're using an earlier version of the Xtensa toolchain, download the required version.
-
If you see an error log like the following about python dependencies that are not being met for ESP-IDF v4.2.
The following Python requirements are not satisfied: click>=5.0 pyserial>=3.0 future>=0.15.2 pyparsing>=2.0.3,<2.4.0 pyelftools>=0.22 gdbgui==0.13.2.0 pygdbmi<=0.9.0.2 reedsolo>=1.5.3,<=1.5.4 bitstring>=3.1.6 ecdsa>=0.16.0 Please follow the instructions found in the "Set up the tools" section of ESP-IDF Getting Started Guide
Install the python dependencies on your platform using the following Python command:
root
/vendors/espressif/esp-idf/requirements.txt
For more troubleshooting information, see Troubleshooting getting started.
Debugging
Debugging code on Espressif ESP32-DevKitC and ESP-WROVER-KIT (ESP-IDF v3.3)
This section shows you how to debug Espressif hardware using ESP-IDF v3.3. To debug using ESP-IDF v4.2, see Debugging code on Espressif ESP32-DevKitC and ESP-WROVER-KIT (ESP-IDF v4.2).
You need a JTAG to USB cable. We use a USB to MPSSE cable (for example, the FTDI C232HM-DDHSL-0
ESP-DevKitC JTAG setup
For the FTDI C232HM-DDHSL-0 cable, these are the connections to the ESP32 DevkitC.
C232HM-DDHSL-0 Wire Color | ESP32 GPIO Pin | JTAG Signal Name |
---|---|---|
Brown (pin 5) |
IO14 |
TMS |
Yellow (pin 3) |
IO12 |
TDI |
Black (pin 10) |
GND |
GND |
Orange (pin 2) |
IO13 |
TCK |
Green (pin 4) |
IO15 |
TDO |
ESP-WROVER-KIT JTAG setup
For the FTDI C232HM-DDHSL-0 cable, these are the connections to the ESP32-WROVER-KIT.
C232HM-DDHSL-0 Wire Color | ESP32 GPIO Pin | JTAG Signal Name |
---|---|---|
Brown (pin 5) |
IO14 |
TMS |
Yellow (pin 3) |
IO12 |
TDI |
Orange (pin 2) |
IO13 |
TCK |
Green (pin 4) |
IO15 |
TDO |
These tables were developed from the
FTDI C232HM-DDHSL-0 datasheet
To enable JTAG on the ESP-WROVER-KIT, place jumpers on the TMS, TDO, TDI, TCK, and S_TDI pins as shown here.

Debugging on Windows (ESP-IDF v3.3)
To set up for debugging on Windows
-
Connect the USB side of the FTDI C232HM-DDHSL-0 to your computer and the other side as described in Debugging code on Espressif ESP32-DevKitC and ESP-WROVER-KIT (ESP-IDF v3.3). The FTDI C232HM-DDHSL-0 device should appear in Device Manager under Universal Serial Bus Controllers.
-
Under the list of universal serial bus devices, right-click the C232HM-DDHSL-0 device, and choose Properties.
Note The device might be listed as USB Serial Port.
In the properties window, choose the Details tab to see the properties of the device. If the device isn't listed, install the Windows driver for FTDI C232HM-DDHSL-0
. -
On the Details tab, choose Property, and then choose Hardware IDs. You should see something like this in the Value field.
FTDIBUS\COMPORT&VID_0403&PID_6014
In this example, the vendor ID is 0403 and the product ID is 6014.
Verify these IDs match the IDs in
projects/espressif/esp32/make/aws_demos/esp32_devkitj_v1.cfg
. The IDs are specified in a line that begins withftdi_vid_pid
followed by a vendor ID and a product ID.ftdi_vid_pid 0x0403 0x6014
-
Download OpenOCD for Windows
. -
Unzip the file to
C:\
and addC:\openocd-esp32\bin
to your system path. -
OpenOCD requires libusb, which is not installed by default on Windows.
To install libusb
-
Download zadig.exe
. -
Run
zadig.exe
. From the Options menu, choose List All Devices. -
From the drop-down menu, choose C232HM-DDHSL-0.
-
In the target driver field, to the right of the green arrow, choose WinUSB.
-
From the dropdown list under the target driver field, choose the arrow, and then choose Install Driver. Choose Replace Driver.
-
-
Open a command prompt, navigate to
projects/espressif/esp32/make/aws_demos
and run the following command.For ESP32-WROOM-32 and ESP32-WROVER
openocd.exe -f esp32_devkitj_v1.cfg -f esp-wroom-32.cfg
For ESP32-SOLO-1
openocd.exe -f esp32_devkitj_v1.cfg -f esp-solo-1.cfg
Leave this command prompt open.
-
Open a new command prompt, navigate to your
msys32
directory, and runmingw32.exe
. -
In the mingw32 terminal, navigate to
projects/espressif/esp32/make/aws_demos
and runmake flash monitor
-
Open another mingw32 terminal, navigate to
projects/espressif/esp32/make/aws_demos
and wait until the demo starts running on your board. When it does, runxtensa-esp32-elf-gdb -x gdbinit build/aws_demos.elf
. The program should stop in themain
function.
The ESP32 supports a maximum of two break points.
Debugging on macOS (ESP-IDF v3.3)
-
Download the FTDI driver for macOS
. -
Download OpenOCD
. -
Extract the downloaded .tar file and set the path in
.bash_profile
to
.OCD_INSTALL_DIR
/openocd-esp32/bin -
Use the following command to install
libusb
on macOS.brew install libusb
-
Use the following command to unload the serial port driver.
sudo kextunload -b com.FTDI.driver.FTDIUSBSerialDriver
-
If you're running a macOS version later than 10.9, use the following command to unload the Apple FTDI driver.
sudo kextunload -b com.apple.driver.AppleUSBFTDI
-
Use the following command to get the product ID and vendor ID of the FTDI cable. It lists the attached USB devices.
system_profiler SPUSBDataType
The output from
system_profiler
should look like the following.DEVICE
: Product ID:product-ID
Vendor ID:vendor-ID
(Future Technology Devices International Limited) -
Open the
projects/espressif/esp32/make/aws_demos/esp32_devkitj_v1.cfg
file. The vendor ID and product ID for your device are specified in a line that begins withftdi_vid_pid
. Change the IDs to match the IDs from thesystem_profiler
output in the previous step. -
Open a terminal window, navigate to
projects/espressif/esp32/make/aws_demos
, and use the following command to run OpenOCD.For ESP32-WROOM-32 and ESP32-WROVER:
openocd -f esp32_devkitj_v1.cfg -f esp-wroom-32.cfg
For ESP32-SOLO-1:
openocd -f esp32_devkitj_v1.cfg -f esp-solo-1.cfg
-
Open a new terminal, and use the following command to load the FTDI serial port driver.
sudo kextload -b com.FTDI.driver.FTDIUSBSerialDriver
-
Navigate to
projects/espressif/esp32/make/aws_demos
, and run the following command.make flash monitor
-
Open another new terminal, navigate to
projects/espressif/esp32/make/aws_demos
, and run the following command.xtensa-esp32-elf-gdb -x gdbinit build/aws_demos.elf
The program should stop at
main()
.
Debugging on Linux (ESP-IDF v3.3)
-
Download OpenOCD
. Extract the tarball and follow the installation instructions in the readme file. -
Use the following command to install libusb on Linux.
sudo apt-get install libusb-1.0
-
Open a terminal and enter
ls -l /dev/ttyUSB*
to list all USB devices connected to your computer. This helps you check if the board's USB ports are recognized by the operating system. You should see output like the following.$ls -l /dev/ttyUSB* crw-rw---- 1 root dialout 188, 0 Jul 10 19:04 /dev/ttyUSB0 crw-rw---- 1 root dialout 188, 1 Jul 10 19:04 /dev/ttyUSB1
-
Sign off and then sign in and cycle the power to the board to make the changes take effect. In a terminal prompt, list the USB devices. Make sure the group owner has changed from
dialout
toplugdev
.$ls -l /dev/ttyUSB* crw-rw---- 1 root plugdev 188, 0 Jul 10 19:04 /dev/ttyUSB0 crw-rw---- 1 root plugdev 188, 1 Jul 10 19:04 /dev/ttyUSB1
The
/dev/ttyUSBn
interface with the lower number is used for JTAG communication. The other interface is routed to the ESP32's serial port (UART) and is used for uploading code to the ESP32’s flash memory. -
In a terminal window, navigate to
projects/espressif/esp32/make/aws_demos
, and use the following command to run OpenOCD.For ESP32-WROOM-32 and ESP32-WROVER:
openocd -f esp32_devkitj_v1.cfg -f esp-wroom-32.cfg
For ESP32-SOLO-1:
openocd -f esp32_devkitj_v1.cfg -f esp-solo-1.cfg
-
Open another terminal, navigate to
projects/espressif/esp32/make/aws_demos
, and run the following command.make flash monitor
-
Open another terminal, navigate to
projects/espressif/esp32/make/aws_demos
, and run the following command:xtensa-esp32-elf-gdb -x gdbinit build/aws_demos.elf
The program should stop in
main()
.
Debugging code on Espressif ESP32-DevKitC and ESP-WROVER-KIT (ESP-IDF v4.2)
This section shows you how to debug Espressif hardware using ESP-IDF v4.2. To debug using ESP-IDF v3.3, see Debugging code on Espressif ESP32-DevKitC and ESP-WROVER-KIT (ESP-IDF v3.3).
You need a JTAG to USB cable. We use a USB to MPSSE cable (for example, the FTDI C232HM-DDHSL-0
ESP-DevKitC JTAG setup
For the FTDI C232HM-DDHSL-0 cable, these are the connections to the ESP32 DevkitC.
C232HM-DDHSL-0 Wire Color | ESP32 GPIO Pin | JTAG Signal Name |
---|---|---|
Brown (pin 5) |
IO14 |
TMS |
Yellow (pin 3) |
IO12 |
TDI |
Black (pin 10) |
GND |
GND |
Orange (pin 2) |
IO13 |
TCK |
Green (pin 4) |
IO15 |
TDO |
ESP-WROVER-KIT JTAG setup
For the FTDI C232HM-DDHSL-0 cable, these are the connections to the ESP32-WROVER-KIT.
C232HM-DDHSL-0 Wire Color | ESP32 GPIO Pin | JTAG Signal Name |
---|---|---|
Brown (pin 5) |
IO14 |
TMS |
Yellow (pin 3) |
IO12 |
TDI |
Orange (pin 2) |
IO13 |
TCK |
Green (pin 4) |
IO15 |
TDO |
These tables were developed from the
FTDI C232HM-DDHSL-0 datasheet
To enable JTAG on the ESP-WROVER-KIT, place jumpers on the TMS, TDO, TDI, TCK, and S_TDI pins as shown here.

Debugging on Windows (ESP-IDF v4.2)
To set up for debugging on Windows
-
Connect the USB side of the FTDI C232HM-DDHSL-0 to your computer and the other side as described in Debugging code on Espressif ESP32-DevKitC and ESP-WROVER-KIT (ESP-IDF v4.2). The FTDI C232HM-DDHSL-0 device should appear in Device Manager under Universal Serial Bus Controllers.
-
Under the list of universal serial bus devices, right-click the C232HM-DDHSL-0 device, and choose Properties.
Note The device might be listed as USB Serial Port.
In the properties window, choose the Details tab to see the properties of the device. If the device isn't listed, install the Windows driver for FTDI C232HM-DDHSL-0
. -
On the Details tab, choose Property, and then choose Hardware IDs. You should see something like this in the Value field.
FTDIBUS\COMPORT&VID_0403&PID_6014
In this example, the vendor ID is 0403 and the product ID is 6014.
Verify these IDs match the IDs in
projects/espressif/esp32/make/aws_demos/esp32_devkitj_v1.cfg
. The IDs are specified in a line that begins withftdi_vid_pid
followed by a vendor ID and a product ID.ftdi_vid_pid 0x0403 0x6014
-
Download OpenOCD for Windows
. -
Unzip the file to
C:\
and addC:\openocd-esp32\bin
to your system path. -
OpenOCD requires libusb, which is not installed by default on Windows.
To install libusb
-
Download zadig.exe
. -
Run
zadig.exe
. From the Options menu, choose List All Devices. -
From the drop-down menu, choose C232HM-DDHSL-0.
-
In the target driver field, to the right of the green arrow, choose WinUSB.
-
From the dropdown list under the target driver field, choose the arrow, and then choose Install Driver. Choose Replace Driver.
-
-
Open a command prompt, navigate to the root of your FreeRTOS download directory, and run the following command.
idf.py openocd
Leave this command prompt open.
-
Open a new command prompt, navigate to the root of your FreeRTOS download directory, and run
idf.py flash monitor
-
Open another command prompt, navigate to the root of your FreeRTOS download directory, and wait until the demo starts running on your board. When it does, run
idf.py gdb
The program should stop in the
main
function.
The ESP32 supports a maximum of two break points.
Debugging on macOS (ESP-IDF v4.2)
-
Download the FTDI driver for macOS
. -
Download OpenOCD
. -
Extract the downloaded .tar file and set the path in
.bash_profile
to
.OCD_INSTALL_DIR
/openocd-esp32/bin -
Use the following command to install
libusb
on macOS.brew install libusb
-
Use the following command to unload the serial port driver.
sudo kextunload -b com.FTDI.driver.FTDIUSBSerialDriver
-
If you're running a macOS version later than 10.9, use the following command to unload the Apple FTDI driver.
sudo kextunload -b com.apple.driver.AppleUSBFTDI
-
Use the following command to get the product ID and vendor ID of the FTDI cable. It lists the attached USB devices.
system_profiler SPUSBDataType
The output from
system_profiler
should look like the following.DEVICE
: Product ID:product-ID
Vendor ID:vendor-ID
(Future Technology Devices International Limited) -
Open the
projects/espressif/esp32/make/aws_demos/esp32_devkitj_v1.cfg
file. The vendor ID and product ID for your device are specified in a line that begins withftdi_vid_pid
. Change the IDs to match the IDs from thesystem_profiler
output in the previous step. -
Open a terminal window, navigate to the root of your FreeRTOS download directory, and use the following command to run OpenOCD.
idf.py openocd
Leave this terminal window open.
-
Open a new terminal, and use the following command to load the FTDI serial port driver.
sudo kextload -b com.FTDI.driver.FTDIUSBSerialDriver
-
Navigate to the root of your FreeRTOS download directory, and run
idf.py flash monitor
-
Open another new terminal, navigate to the root of your FreeRTOS download directory, and run
idf.py gdb
The program should stop at
main
.
Debugging on Linux (ESP-IDF v4.2)
-
Download OpenOCD
. Extract the tarball and follow the installation instructions in the readme file. -
Use the following command to install libusb on Linux.
sudo apt-get install libusb-1.0
-
Open a terminal and enter
ls -l /dev/ttyUSB*
to list all USB devices connected to your computer. This helps you check if the board's USB ports are recognized by the operating system. You should see output like the following.$ls -l /dev/ttyUSB* crw-rw---- 1 root dialout 188, 0 Jul 10 19:04 /dev/ttyUSB0 crw-rw---- 1 root dialout 188, 1 Jul 10 19:04 /dev/ttyUSB1
-
Sign off and then sign in and cycle the power to the board to make the changes take effect. In a terminal prompt, list the USB devices. Make sure the group owner has changed from
dialout
toplugdev
.$ls -l /dev/ttyUSB* crw-rw---- 1 root plugdev 188, 0 Jul 10 19:04 /dev/ttyUSB0 crw-rw---- 1 root plugdev 188, 1 Jul 10 19:04 /dev/ttyUSB1
The
/dev/ttyUSBn
interface with the lower number is used for JTAG communication. The other interface is routed to the ESP32's serial port (UART) and is used for uploading code to the ESP32’s flash memory. -
In a terminal window, navigate to the root of your FreeRTOS download directory, and use the following command to run OpenOCD.
idf.py openocd
-
Open another terminal, navigate to the root of your FreeRTOS download directory, and run the following command.
idf.py flash monitor
-
Open another terminal, navigate the root of your FreeRTOS download directory, and run the following command:
idf.py gdb
The program should stop in
main()
.