NIMBU

Prerequisites

mkdir -p esp
cd esp
git clone --recursive https://github.com/espressif/esp-idf.git
cd esp-idf
./install.sh all

Now that ESP-IDF is installed, we'll also install an alias to quickly launch the ESP-IDF environment.

echo "alias launch_idf='. $HOME/esp/esp-idf/export.sh'" >> ~/.bashrc
source ~/.bashrc

Project Structure

root
├── nimbu
│   ├── build
│   ├── CMakeLists.txt
│   ├── components
│   ├── main
│   │   ├── bt
│   │   ├── CMakeLists.txt
│   │   ├── common
│   │   ├── led
│   │   ├── main.cpp

Nimbu is based on ESP-IDF, which runs on FreeRTOS.
All commands related to ESP-IDF funcitonality - building/flashing/etc should be done from within the nimbu folder.

cd nimbu

components contains the ESP-IDF tools and libs required for building the application.
main contains the entire source.
Make sure that the path to CMake is that of the linked ESP-IDF installation.

Configure the project

Current sdkconfig already includes the necessary settings.
In case reconfiguration is required, make sure to:

• Set the use of external I2S codec for audio output, and configure the output PINs
• Enable Classic Bluetooth and A2DP under Component config --> Bluetooth --> Bluedroid Enable

idf.py set-target esp32
idf.py menuconfig

Build and Flash

Build the project.

idf.py build

Flash it to the board, then run monitor tool to view serial output.

idf.py -p PORT flash monitor

(To exit the serial monitor, type Ctrl-].)