35. I2S EMULATION
35.1. Overview
This sample show use SPI transmit and receive audio data to audio codec
The evaluation board needs to be connected to the audio decoding module. This example uses wm8978
35.2. Notice
Since the SPI used in this example requires a large transmission length, it currently only supports the hpm5300 series.
35.3. dependent components
dma_mgr
spi
i2s_over_spi
codec(wm8978)
35.4. Board Setting
Recording via the onboard mic of the audio module
Connecting 3.5mm headphones to the headphone output port of the audio module
Need to use GPTMR output and SPI pins，pins(Please refer to Pin Description)
5V <–> 5V(WM8978)
3.3V <–> 3.3V(WM8978)
GND <–> GND(WM8978)
MCLK(GPTMR) <–> MCLK(WM8978)
LRCK(GPTMR) <–> (FSA)LRC(WM8978)
BLCK(GPTMR) <–> SCLK(SPI) <–> SCK(WM8978)
MISO(SPI) <–> (DAT)DACDATA(WM8978)
MOSI(SPI) <–> (SDB)ADCDATA(WM8978)
(CS)GPIO <–> CS(SPI)
I2C_SDA <–> I2C_SDA(WM8978)
I2C_SCL <–> I2C_SCL(WM8978)
35.5. Run steps
When the project runs correctly, the serial port terminal will output the information like
---------------------------------------------------------------
* *
* i2s_emulation demo *
* *
* 1 - start play *
* 2 - stop play *
* 3 - start record *
* 4 - stop record *
*-------------------------------------------------------------*
Enter the ‘3’ character into the terminal to start recording. If the recording duration is longer than the specified duration, it will automatically exit and save.
record_start enter....
record size overflow, now exit..
Enter the ‘1’ character in the terminal to start recording playback
play start enter....
play end, now exit....
Enter the ‘4’ character in the terminal to stop recording.
record stop finish....
Enter the ‘2’ character in the terminal to stop playing
play stop finish....