esp-idf/examples/peripherals/i2s/i2s_basic/README.md

Supported Targets	ESP32	ESP32-S2	ESP32-C3	ESP32-S3

I2S Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

In this example, we generate a 100Hz triangle and sine wave and send it out from left and right channels at a sample rate of 36kHz through the I2S bus.

How to Use Example

Hardware Required

• A development board with ESP32/ESP32-S2/ESP32-C3/ESP32-S3 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
• A USB cable for power supply and programming

Configure the Project

idf.py menuconfig

Build and Flash

Build the project and 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-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

Running this example, you will see I2S start to read and write data, and only the first 4 elements in the receive buffer will be displayed. The output log can be seen below:

[i2s write] 1440 bytes are written successfully

[i2s read] 8192 bytes are read successfully
----------------------------------------------
[0]    0 [1]    0 [2]    0 [3]    0

[i2s write] 1440 bytes are written successfully
[i2s write] 1440 bytes are written successfully
[i2s write] 1440 bytes are written successfully

[i2s read] 8192 bytes are read successfully
----------------------------------------------
[0] a7d468d9 [1] a88a6a1d [2] a9406b58 [3] a9f66c8b

[i2s write] 1440 bytes are written successfully
[i2s write] 1440 bytes are written successfully

[i2s read] 8192 bytes are read successfully
----------------------------------------------
[0] 8b622120 [1] 8c182347 [2] 8cce256c [3] 8d84278d

There is a abnormal case that printing Data dropped, it is caused by a long polling time of i2s_channel_read, please refer to the Application Notes section in I2S API reference.

[i2s read] 8192 bytes are read successfully
----------------------------------------------
[0] a7d468d9 [1] a88a6a1d [2] a9406b58 [3] a9f66c8b


[i2s monitor] Data dropped


[i2s monitor] Data dropped


[i2s monitor] Data dropped

[i2s write] 1440 bytes are written successfully

[i2s monitor] Data dropped

If you have a logic analyzer, you can use a logic analyzer to grab online data. The following table describes the pins we use by default (Note that you can also use other pins for the same purpose).

pin name	function	gpio_num
WS	word select	GPIO_NUM_15
SCK	continuous serial clock	GPIO_NUM_13
SD	serial data	GPIO_NUM_21

Troubleshooting

• Program upload failure

  • Hardware connection is not correct: run idf.py -p PORT monitor, and reboot your board to see if there are any output logs.
  • The baud rate for downloading is too high: lower your baud rate in the menuconfig menu, and try again.

For any technical queries, please open an issue on GitHub. We will get back to you soon.