Hi all! just ordered a olinuxino a20, and I'm new to this devboard world :)
Since I cannot find much documentation about this board (but features are so good that can fit my projects) I would like to ask some questions:
- I plan to build an "expansion card" to interface olinuxino with an arcade cabinet that has his PSU that supplies 12V and +/-5V on some pins of the jamma fingerboard ("the interface"). What's the best method to provide power to the olinuxino? can I feed 5V into one of the enabled GPIO pins or should I route the 12V signal to the power socket? the thing is, it wolud be great if I can build a duino-like-shield that simply plug to gpio socket(s). do I have some chance?
- I red about GPIO ugly driver for A13, but I saw here (https://github.com/linux-sunxi/linux-sunxi/commit/c13a737e601a0cffe61fb2486cde93aa016fe0a8) that gpio-sunxi implementation changed (for good). Unfortunately in Kconfig it states that it depends on arch_sun3i,arch_sun4i or arch_sun5i. Does it work with A20 (arch_sun7i) also? It's just a matter of adding the arch on kconfig or is it something more difficult?
- is there a way to acces to audio out from the gpio connectors? Just like the power, I have to take the audio out, amplify it and than route it to the fingerboard.
Thanks in advance for your time!
Cheers from Italy
I've just ordered an A20 board so I reply for having read docs, not from 1st hand experience.
Anyway I think you have to supply 12V to the power plug.
I don't think Gpio are for providing power to the board.
And, I don't think they can output audio, either.
A20 has I2S audio out if you need digital audio out and analog out 44/48khz from stereo headphone plug.
Also consider that Gpio are not supported yet under Linux (no kernel support)
Quote from: XFer on July 19, 2013, 07:12:10 PM
I've just ordered an A20 board so I reply for having read docs, not from 1st hand experience.
Thanks Xfer, you confirmed the same thing I discovered running through the (poor) documentation.
For the audio I can solve with a DAC (even though I'm trying to keep my board simple).
For the power, I assumed it's like arduino, where you can feed a steady 5V (or 3.3V for arduino due) directly from the pins, bypassing the board's voltage regulator.
I hope GPIO support will come soon because is the main reason I bought this gorgeous board! :)
Thanks again,
have fun with your board!
Hi,
I come from Arduino, too.
These Olinuxino boards are quite different, expecially regarding power supply and Gpio.
Please let's keep in contact about audio: for my project I'll make do with integrated DAC for now, but I'd like to switch to digital audio output + external DAC next (I'm designing a MIDI expander box so audio quality is important).
Fernando