How do you control the volume for arecord when no HDMI is connected? It appears that alsa functions are gone in NOOBS 2.4.2 and Xwindows controls the audio, but without the HDMI hooked up is Xwindows even there? I need to control the volume thru the terminal serial connection.
1 Answer
You can control the audio device using the alsamixer command. If you want complete command line control, you can control the alsa mixer using the amixer command.
For example you can control the master volume like so :
amixer sset Master 0dB
This command sets the Master volume to 0 dB.
You can list the available simple controls using the amixer scontrols command, here is an example :
pi@raspberrypi:~ $ amixer scontrols
Simple mixer control 'Master',0
Simple mixer control 'Master Playback ZC',0
Simple mixer control 'Sidetone',0
Simple mixer control 'Line',0
Simple mixer control 'Mic',0
Simple mixer control 'Mic Boost',0
Simple mixer control 'Playback Deemphasis',0
Simple mixer control 'Capture',0
Simple mixer control 'ADC High Pass Filter',0
Simple mixer control 'Input Mux',0
Simple mixer control 'Output Mixer HiFi',0
Simple mixer control 'Output Mixer Line Bypass',0
Simple mixer control 'Output Mixer Mic Sidetone',0
Simple mixer control 'Store DC Offset',0
