Greetings everyone.
I'm working on the audio part of my pi. Basically, I wanna the audio part works like an iphone.
My Target:
1) built-in speakers, but when the 3.5mm jack inserted, it works on the earphone.
2) buttons to volume up or volume down.
3) a mute button. (optional)
My research:
a) I find a connector in the local market, which meets target 1, pretty clear and easy.
REF:http://www.ebay.com/itm/20Pcs-3-5mm-Fem ... 1486756940
b) I read some threads says that if you use the audio from 3.5mm on pi, you'd better control the volume via an audio amplifier and keep the system 100% output.
c) I searched through ebay to look for some audio amplifier, there're basically 3 kinds.
c.1) Adfruit kit. seems everything on it, but a little expensive. Link: http://www.ebay.com/itm/Adafruit-Stereo ... 1387905614
c.2) some third-party kit. also everything on it, also expensive (even more). Link: http://www.ebay.com/itm/mini-USB-audio- ... 1114540729
c.3) the very basic board. really cheap but requires a lot more work. Link: http://www.ebay.com/itm/DC-5V-2x3W-Digi ... 1578760302
My concerns:
i) my idea is that the audio from pi goes to an audio amplifier, and the audio amplifier goes to the connector which holds speaker and earphone jack, is it possible?
ii) I've noticed that an audio amplifier works on 3.3v or 5v usually goes with the speaker up to 8 ohms, but we know the every earphone is 32 ohms, is this okay to match?
iii) if I power it from the GPIO pins, is it enough ?
iv) any other better solution ?
Sincerely thanks