- path: ./idf_component_examples/hw_cdc_hello_world

cmake_minimum_required(VERSION 3.16)

include($ENV{IDF_PATH}/tools/cmake/project.cmake)

list(APPEND compile_definitions "ARDUINO_USB_CDC_ON_BOOT=1")

list(APPEND compile_definitions "ARDUINO_USB_MODE=1")

project(hw_cdc_hello_world)

| Supported Targets | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-S3 |

| ----------------- | -------- | -------- | -------- | -------- |

This is the simplest buildable example made to be used as a template for new projects running Arduino-ESP32 as an ESP-IDF component that will redefine the `Serial` interface to be attached to the USB CDC Hardware Serial port.\

See [arduino-esp32](https://components.espressif.com/components/espressif/arduino-esp32) in ESP Registry.

After cloning this repository, go to the `hw_cdc_hello_world` folder and select the target by executing\

`idf.py set-target <SoC_target>`.\

`<SoC_target>` can be one of the installed IDF version supported targets.

It is possible to just clone this folder be executing\

For IDF 5.1.x and forward, the list of targets that support Hardware USB CDC are, at least: esp32s3, esp32c3, esp32c6 and esp32h2.\

Then just run command: `idf.py build` or `idf.py -p USB_PORT flash monitor`.

Usually, it is necessary to make the ESP32 SoC to enter in `Download Mode` before uploading the firmware.\

After that, just press `RESET/EN` to start the new firmware.

The project **hw_serial_example** contains one source file in C++ language [main.cpp](main/main.cpp). The file is located in folder [main](main).

ESP-IDF projects are built using CMake. The project building configuration is contained in `CMakeLists.txt`

file that provide a set of directives and instructions describing the project's source files and targets

(executable, library, or both).

Below is the minimum list of files in the project folder.

ESP32 Arduino has two macro defined symbols that control what `Serial` symbol will represent.

Default `Serial` is the UART0 from `HardwareSerial` class.

`Serial` can be changed to be attached to the HW Serial JTAG port fro the SoC.

In order to make it work, it is necessary to define 2 symbols: `ARDUINO_USB_CDC_ON_BOOT` and `ARDUINO_USB_MODE` to `1`.

This is achieved by adding a couple lines to the [Project Folder CMakeLists.txt](CMakeLists.txt) file.

Those two lines will add a `-DSYMBOL=VAL` when compiling every source code file.

In order to make sure that it is actually working correctly, the [sketch](main/main.cpp) will execute `Serial.begin();` with no baudrate, which only works for USB CDC.

idf_component_register(

SRC_DIRS "."

INCLUDE_DIRS "."

)

dependencies:

espressif/arduino-esp32:

version: "*"

override_path: "../../../"

pre_release: true

#include <Arduino.h>

void setup() {

// USB CDC doesn't need a baud rate

Serial.begin();

// wait for the Serial Monitor to be open

while (!Serial) {

delay(100);

}

Serial.println("\r\nStarting...\r\n");

}

void loop() {

Serial.println("Hello world!");

delay(1000);

}

#

# Arduino ESP32

#

CONFIG_AUTOSTART_ARDUINO=y

# end of Arduino ESP32

#

# FREERTOS

#

CONFIG_FREERTOS_HZ=1000

# end of FREERTOS

# end of Component config