This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
chumbyhackerboard:audio [2010/08/30 18:02] ladyada |
chumbyhackerboard:audio [2010/08/30 19:37] ladyada |
||
---|---|---|---|
Line 8: | Line 8: | ||
MP3's will play in the background. To kill **btplay** run **killall btplay** | MP3's will play in the background. To kill **btplay** run **killall btplay** | ||
- | Audio will play through the headphone jack at max volume, just plug in your favorite headphones! | + | Audio will play through the headphone jack at max volume, just plug in your favorite headphones! (Warning: it may be really loud!) |
====== Playing remote MP3s! ====== | ====== Playing remote MP3s! ====== | ||
- | You can also stream music with **btplay**, just stick a URL in there! | + | You can also stream music with **btplay**, just stick a URL in there! Of course, you will have to have network capability up and running first |
{{:chumbyhackerboard:soma.gif|}} | {{:chumbyhackerboard:soma.gif|}} | ||
- | Just as before, just plug into the headphone jack to verify its working | + | Just as before, just plug into the headphone jack to verify its working. (Warning: it may be really loud!) |
+ | |||
+ | ====== Splitting out the A/V ====== | ||
+ | |||
+ | The headphone jack is not actually just audio - its actually Audio and Video. That means that you if you just plug headphones you'll notice some buzzing - thats you listening to the video! Now if you're in a Cronenberg film this is probably OK but for most of us its very annoying! There are two solutions. One is to split out the 3 signals into RCA jacks (with a camcorder cable) | ||
+ | |||
+ | {{http://www.adafruit.com/images/medium/avcable_MED.jpg}} | ||
+ | |||
+ | and then recombining with an RCA Y cable (such as [[http://www.sweetwater.com/store/detail/YRA154/|a Y female-RCA to male 3.5mm]] or [[http://www.sweetwater.com/store/detail/CMR206/|this]] | ||
+ | |||
+ | |||
+ | **Note** our A/V cables split out the signals as such - **Red** is Video, **White** and **Yellow** are stereo line-level audio which is not what you would expect! | ||
+ | |||
+ | **Note Note** apparently like every A/V cable is slightly different. If you get one, try different colors to figure out which ones have audio coming out of them and which have video. | ||
====== Using the Mixer ====== | ====== Using the Mixer ====== | ||
Line 23: | Line 36: | ||
{{:chumbyhackerboard:amixer.gif|}} | {{:chumbyhackerboard:amixer.gif|}} | ||
+ | |||
+ | You can get and change the HeadPhone volume (**HP**) by running **amixer sget HP** and **amixer sset HP** | ||
+ | |||
+ | {{:chumbyhackerboard:sgethp.gif|}} | ||
+ | |||
+ | To set the volume to 1/2 for example, do this **amixer sset HP 64** | ||
+ | |||
+ | {{:chumbyhackerboard:ssethp.gif|}} | ||
+ | |||
+ | ====== Speaker ====== | ||
+ | |||
+ | The iMX.233 has a built-in mono speaker amplifier that can push up to 2W into a 4 ohm speaker! To use, connect the two speaker inputs into the **Spkr** 0.1" JST connection near the power jack. You can use either pin, they are not polarized as it is a mono output. Don't ground either of the speaker pins, they are "bridge tied" to improve output volume | ||
+ | |||
+ | The chumby is 'switched' by default - if you connect headphones into the jack, the speaker will turn off and vice versa. | ||
+ | |||
+ | If you want the speaker on even with the headphone plugged in, you can use **amixer cset** | ||
+ | |||
+ | {{:chumbyhackerboard:amixercset.gif|}} | ||
+ | |||
+ | For example, the Speaker Playback Switch is off, so we turn it on with **amixer cset numid=4 on** to reactivate |