91 lines
3.1 KiB
Markdown
91 lines
3.1 KiB
Markdown
# I2S Built-in ADC/DAC Example
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(See the README.md file in the upper level 'examples' directory for more information about examples.)
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In this example, we configure I2S to work in I2S_ADC and I2S_DAC modes and then:
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* recording sound from ADC,
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* playing the recorded sound,
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* playing an audio file in flash via DAC.
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#### Note:
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The `tools` directory contains `generate_audio_file.py` script for generating audio files:
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* The script provides an example of generating audio tables from `.wav` files.
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* In this example, the `wav` file must be in 16k/16bit mono format.
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* The script will bundle the `wav` files into a single table named `audio_example_file.h`.
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* Since the ADC can only play 8-bit data, the script will scale each 16-bit value to a 8-bit value.
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* The script will covert all signed values into unsigned values because only positive values will be output by the ADC.
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## How to Use Example
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### Hardware Required
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* A development board with ESP32 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
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* A USB cable for power supply and programming
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* A microphone (with amplifier) and one or two speaker(s) for testing.
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The following is the hardware connection:
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|hardware|module|GPIO|
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|:---:|:---:|:---:|
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|Microphone|ADC1_CH0|GPIO36|
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|speaker(R)|DAC1|GPIO25|
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|speaker(L)|DAC2|GPIO26|
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### Configure the Project
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```
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make menuconfig
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```
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* Set serial port under Serial Flasher Options, the flash size should be set to 4 MB.
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* Select "Custom partition table CSV" and rename "Custom partition CSV file" to "partitions_adc_dac_example.csv".
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(Note that you can use `sdkconfig.defaults`)
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### Build and Flash
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Build the project and flash it to the board, then run monitor tool to view serial output:
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```
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make -j4 flash monitor
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```
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(To exit the serial monitor, type ``Ctrl-]``.)
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See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
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## Example Output
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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:
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```
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partiton addr: 0x00110000; size: 2097152; label: storage
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Erasing flash
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partiton addr: 0x00110000; size: 2097152; label: storage
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Erase size: 323584 Bytes
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I2S: PLL_D2: Req RATE: 16000, real rate: 1004.000, BITS: 16, CLKM: 83, BCK: 60, MCLK: 83.333, SCLK: 32128.000000, diva: 64, divb: 21
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Sound recording 5%
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Sound recording 10%
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...
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Sound recording 97%
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Sound recording 102%
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playing: 0 %
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playing: 1 %
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playing: 2 %
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...
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playing: 96 %
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playing: 97 %
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playing: 98 %
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Playing file example:
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I2S: PLL_D2: Req RATE: 16000, real rate: 1004.000, BITS: 16, CLKM: 83, BCK: 60, MCLK: 83.333, SCLK: 32128.000000, diva: 64, divb: 21
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```
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## Troubleshooting
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* Program upload failure
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* Hardware connection is not correct: run `make monitor`, and reboot your board to see if there are any output logs.
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* The baud rate for downloading is too high: lower your baud rate in the `menuconfig` menu, and try again.
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For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.
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