67 lines
2.6 KiB
Markdown
67 lines
2.6 KiB
Markdown
# I2S 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 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.
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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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### 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.
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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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Running this example, you will see the Bits per Sample changes every 5 seconds after you have run this example. You can use `i2s_set_clk` to change the Bits per Sample and the Sample Rate. The output log can be seen below:
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```
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Test bits=24 free mem=293780, written data=2880
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I2S: DMA Malloc info, datalen=blocksize=480, dma_buf_count=6
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I2S: PLL_D2: Req RATE: 36000, real rate: 37878.000, BITS: 24, CLKM: 11, BCK: 8, MCLK: 13837837.838, SCLK: 1818144.000000, diva: 64, divb: 36
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Test bits=32 free mem=292336, written data=2880
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I2S: DMA Malloc info, datalen=blocksize=480, dma_buf_count=6
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I2S: PLL_D2: Req RATE: 36000, real rate: 36764.000, BITS: 32, CLKM: 17, BCK: 4, MCLK: 9216921.692, SCLK: 2352896.000000, diva: 64, divb: 23
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Test bits=16 free mem=293772, written data=1440
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I2S: DMA Malloc info, datalen=blocksize=240, dma_buf_count=6
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I2S: PLL_D2: Req RATE: 36000, real rate: 36764.000, BITS: 16, CLKM: 17, BCK: 8, MCLK: 9216921.692, SCLK: 1176448.000000, diva: 64, divb: 23
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```
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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).
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| pin name| function | gpio_num |
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|:---:|:---:|:---:|
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| WS |word select| GPIO_NUM_25 |
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| SCK |continuous serial clock| GPIO_NUM_26 |
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| SD |serial data| GPIO_NUM_22 |
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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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