Audio（ROM-5880）
From ESS-WIKI
ROM-5880 supports 2 sound cards: 0 hdmi (with Audio), 1 rt5640-codec. (Connect Audio boardROM-EG57 on CN17 of SOM-DB2510 carrier board, set SW3 to 2.)
Step 1：HDMI
Set the default audio output when playing media files, if it supports audio.
1. Entry start->Sound & Video->PulseAudio Volume Control.
2. Select “Build-in Audio stereo” for HDMI output or Select “Build-in Audio Speaker …” for rt5640-codec output.
Step 2：Audio codec
1. Get sound card ID.
# cat /proc/asound/cards 0 [rockchiphdmi ]: rockchip_hdmi - rockchip,hdmi rockchip,hdmi 1 [rockchiprt5640c]: rockchip_rt5640 - rockchip,rt5640-codec rockchip,rt5640-codec
2. Record（0/1->rt5640-codec）
Take Card ID 1 for example：
# arecord -Dplughw:1,0 -f S16_LE -r 16000 -d 10 -t wav test.wav
3. Playback
Take Card ID 1 for example：
# aplay -Dplughw:1,0 -t wav test.wav