NuMaker-mbed-Audio

This library contains Mbed implementation of NuMaker Audio I2S and Codec.

Example: Play PCM data from SD card

1. Declare NuSDBlockDevice and FATFileSystem.

   NuSDBlockDevice bd   // device SD driver
   FATFileSystem fs     // Mbed FAT file system
   

2. Declare audio.

   NAU8822L audio  // NAU8822L object, I2C pinout/address and I2S pinout
   or
   NAU88L25 audio  // NAU88L25 object, I2C pinout/address and I2S pinout
   

3. Attach callback function for playing.

   audio.attach(&play);
   

4. Start audio.

   audio.start();
   

5. Stop playing.

   audio.stop();
   

6. Write PCM data to audio.

   audio.write
   

Example: Record PCM data to SD card

1. Attach callback function for recording.

   audio.attach(&record);
   

2. Record audio.

   audio.record();
   

3. Stop recording.

   audio.stop();
   

4. Read PCM data from audio.

   audio.read();
   

Notes:

1. Smoothly playing or recording depends on the performance of SD card.

2. Use FFmpeg to convert a PCM file.

   ffmpeg.exe -hide_banner -i audio_file -map_metadata -1 -flags +bitexact -vn -sn -c:a pcm_s16le -ac 1 -ar 8000 -f s16le test.pcm