The `tools` directory contains `generate_audio_file.py` script for generating audio files:
* The script provides an example of generating audio tables from `.wav` files.
* In this example, the `wav` file must be in 16k/16bit mono format.
* The script will bundle the `wav` files into a single table named `audio_example_file.h`.
* Since the ADC can only play 8-bit data, the script will scale each 16-bit value to a 8-bit value.
* The script will covert all signed values into unsigned values because only positive values will be output by the ADC.
## How to Use Example
### Hardware Required
* A development board with ESP32 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
* A USB cable for power supply and programming
* A microphone (with amplifier) and one or two speaker(s) for testing.
The following is the hardware connection:
|hardware|module|GPIO|
|:---:|:---:|:---:|
|Microphone|ADC1_CH0|GPIO36|
|speaker(R)|DAC1|GPIO25|
|speaker(L)|DAC2|GPIO26|
### Configure the Project
```
make menuconfig
```
* Set serial port under Serial Flasher Options, the flash size should be set to 4 MB.
* Select "Custom partition table CSV" and rename "Custom partition CSV file" to "partitions_adc_dac_example.csv".
(Note that you can use `sdkconfig.defaults`)
### Build and Flash
Build the project and flash it to the board, then run monitor tool to view serial output:
```
make -j4 flash monitor
```
(To exit the serial monitor, type ``Ctrl-]``.)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
## Example Output
Reset your development board. The application it will first record the sound through the microphone. Then it will play the recorded sound, and finally a piece of audio stored in the flash. The following is the output log:
