Difference between revisions of "Raspberry Pi ALSA"
From WA2IAC Wiki
(→Volume Control) |
(→More on the ALSA Sound Drivers and Utilities) |
||
| Line 51: | Line 51: | ||
You can find useful information in the directory /proc, which is a “virtual” file system (meaning that it does not exist in real life, but merely is a mapping to various processes and tasks in your computer). | You can find useful information in the directory /proc, which is a “virtual” file system (meaning that it does not exist in real life, but merely is a mapping to various processes and tasks in your computer). | ||
| − | * /proc/modules gives information about loaded kernel modules. The command lsmod | grep snd will list modules relevant to the sound system. | + | * /proc/modules gives information about loaded kernel modules. The command ''lsmod | grep snd'' will list modules relevant to the sound system. |
| − | * You can check the existence of a soundcard by looking at cat /proc/asound/cards. | + | * You can check the existence of a soundcard by looking at cat ''/proc/asound/cards''. |
The amixer command can provide useful information (sometimes): | The amixer command can provide useful information (sometimes): | ||
| − | You can look at the mixer settings by typing amixer without any arguments. This command lists the mixer settings of the various parts of the soundcard. The output from amixer can greatly differ from card to card. Unfortunately you can’t find much documentation on how to interpret the out. | + | You can look at the mixer settings by typing ''amixer'' without any arguments. This command lists the mixer settings of the various parts of the soundcard. The output from amixer can greatly differ from card to card. Unfortunately you can’t find much documentation on how to interpret the out. |
| − | The RPi doesn’t have a “Master” control only “PCM”. So commands like amixer set Master... will not work. You must use amixer set PCM ... | + | The RPi doesn’t have a “Master” control only “PCM”. So commands like amixer ''set Master''... will not work. You must use amixer set PCM ... |
You can mute /unmute the sound via these commands: amixer set PCM mute and amixer set PCM unmute | You can mute /unmute the sound via these commands: amixer set PCM mute and amixer set PCM unmute | ||
