PDM Example

Source path: example/multimedia/audio/4pdm

Supported Platforms

• sf32lb56-lcd_a128r12n1

Overview

This example demonstrates two or four PDM mic recording, using Ankai’s algorithm by default, which includes:

• Recording through PDM and saving the recording as a wav file.

• Reading the recorded data and playing it back.

Example Usage

Hardware Requirements

Before running this example, you need to prepare:

• One development board supported by this example (Supported platforms).

• PDM

• Speaker.

menuconfig Configuration

1. Enable PDM (two mics using PDM1 left and right, four mics using PDM1、PDM2)

2. Enable AUDIO CODEC and AUDIO PROC:

3. Enable AUDIO

4. Enable AUDIO MANAGER

Tip

Configurations 3 and 4 are for playing recorded files. In this example, recording playback uses Audio manager interface.

Hardware Connection\PIN CONFIG

Check which port the PDM uses. If the bsp_pinmux.c in the board is not configured, you need to configure the pin function to PDM.

• For more detailed pin definitions, please refer to sf32lb52-nano sf32lb52-lcd sf32lb56-lcd sf32lb58-lcd

take f32lb56-lcd_a128r12n1 as a example：

    /* PIN CONFIG */
    HAL_PIN_Set(PAD_PA69, PDM1_CLK, PIN_NOPULL, 1);
    HAL_PIN_Set(PAD_PA64, PDM1_DATA, PIN_PULLDOWN, 1);
    HAL_PIN_Set(PAD_PA73, PDM2_CLK, PIN_NOPULL, 1);
    HAL_PIN_Set(PAD_PA71, PDM2_DATA, PIN_PULLDOWN, 1);

Compilation and Programming

Switch to the example project directory and run the scons command to execute compilation:

> scons --board=f32lb56-lcd_a128r12n1 -j32

Switch to the example project/build_xx directory and run uart_download.bat, select the port as prompted to download:

$ ./uart_download.bat

     Uart Download

please input the serial port num:5

For detailed steps on compilation and downloading, please refer to the relevant introduction in Quick Start.

Expected Results

1. Start recording command: pdm open [PDM interface selection] [number of channels] [algorithm selection]
   For example:
   pdm open pdm1 1 raw
   Indicates configuring PDM1 for mono recording, generating pdm1_1.wav, without any algorithm, suitable for factory testing.
   pdm open pdm1 2 raw
   Indicates configuring PDM1 for stereo recording, generating pdm1_2.wav, without any algorithm, suitable for factory testing.
   pdm open pdm2 1 raw
   Indicates configuring PDM2 for mono recording, generating pdm2_1.wav, without any algorithm, suitable for factory testing.
   pdm open pdm2 2 raw
   Indicates configuring PDM2 for stereo recording, generating pdm2_2.wav, without any algorithm, suitable for factory testing.
   pdm open pdm12 4 raw
   Indicates configuring PDM1/PDM2 each for stereo, without any algorithm, suitable for factory testing, only outputting log.

pdm open pdm1 1 anyka
Indicates configuring PDM1 for mono recording, using Anyka algorithm, output as mono, generating anyka_pdm1_1.wav.
pdm open pdm1 2 anyka
Indicates configuring PDM1 for stereo recording, using Anyka algorithm, output as mono, generating anyka_pdm1_2.wav.
pdm open pdm2 1 anyka
Indicates configuring PDM2 for mono recording, using Anyka algorithm, output as mono, generating anyka_pdm2_1.wav.
pdm open pdm2 2 anyka
Indicates configuring PDM2 for stereo recording, using Anyka algorithm, output as mono, generating anyka_pdm2_2.wav.
pdm open pdm12 4 anyka
Indicates configuring PDM1/PDM2 each for stereo, using Anyka algorithm, output as mono, generating anyka_4.wav.

2. Stop recording command: pdm close
   pdm close
   Indicates stopping the recording.

3. Playback recording command: pdm play [filename]
   For example:
   pdm play anyka_pdm2_2.wav

After recording, executing playback will allow normal recording and playback.

Exception Diagnosis

Reference Documentation

Update Log

Version	Date	Release Notes
0.0.1	12/2024	Initial version