Difference between revisions of "AudioIn"
Ashcharles (Talk | contribs) (Created page with "Some Overo expansion boards provide a standard Audio Out and an Audio Line-in. Without a pre-amplifier, plugging a microphone into this Line-In port just won't work. To use a m…") |
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| − | + | Each Gumstix expansion board that has a "3.5-mm stereo headset jack", such as the [http://www.gumstix.com/store/catalog/product_info.php?products_id=255 Gallop43 board], has a mic-in line so a microphone can be plugged in directly. Make sure to use a kernel that is more recent than 25 Sept. 2010 - see [http://www.sakoman.com/feeds/omap3/glibc/images/overo/ here] for recent pre-built images. | |
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| + | Each expansion board that has "stereo audio in" rather than a "headset jack", such as the [http://www.gumstix.com/store/catalog/product_info.php?cPath=31_40&products_id=230 Tobi board] or [http://www.gumstix.com/store/catalog/product_info.php?products_id=229 Palo43 board], does not have a mic-in line so a microphone cannot be plugged in directly. An amplifier would be needed for a microphone since there isn't a pre-amplifier. | ||
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| + | Check the features listed on the product page of each [http://www.gumstix.com/store/catalog/index.php?cPath=31_40 expansion board] to determine if the expansion board has a stereo headset jack or stereo audio-in. | ||
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== Capture Interface Settings == | == Capture Interface Settings == | ||
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$ amixer -c 0 sset 'Analog Right Sub Mic' cap | $ amixer -c 0 sset 'Analog Right Sub Mic' cap | ||
</code> | </code> | ||
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| + | To test, you might use something like this; it records for two seconds and then plays back the recorded sound. | ||
| + | <code> | ||
| + | $ arecord -d 2 -f cd -t wav foobar.wav;aplay foobar.wav | ||
| + | </code> | ||
| + | |||
| + | |||
| + | |||
| + | [[Category:How_to_-_audio]] | ||
Latest revision as of 22:39, 15 January 2011
Each Gumstix expansion board that has a "3.5-mm stereo headset jack", such as the Gallop43 board, has a mic-in line so a microphone can be plugged in directly. Make sure to use a kernel that is more recent than 25 Sept. 2010 - see here for recent pre-built images.
Each expansion board that has "stereo audio in" rather than a "headset jack", such as the Tobi board or Palo43 board, does not have a mic-in line so a microphone cannot be plugged in directly. An amplifier would be needed for a microphone since there isn't a pre-amplifier.
Check the features listed on the product page of each expansion board to determine if the expansion board has a stereo headset jack or stereo audio-in.
Capture Interface Settings
The audio Line-in uses the 'Analog Right AUXR' and the 'Analog Left AUXL' lines; the Mic-in uses the 'Analog Left Main Mic' and the 'Analog Right Sub Mic' lines. Use amixer or alsamixer to select the correct capture interface for your application.
Currently, Line-in is selected as the default capture interface. You could switch to the Mic-in interface like this:
$ amixer -c 0 sset 'Analog Right AUXR' nocap $ amixer -c 0 sset 'Analog Left AUXL' nocap $ amixer -c 0 sset 'Analog Left Main Mic' cap $ amixer -c 0 sset 'Analog Right Sub Mic' cap
To test, you might use something like this; it records for two seconds and then plays back the recorded sound.
$ arecord -d 2 -f cd -t wav foobar.wav;aplay foobar.wav
