N00B help with an embedded SBC
 

Hey guys,

I'm new to the world of embedded systems etc. and am looking for reccomendations on a SBC to help me learn, but also be used for a particular project I'd like to try.

I want to use an embedded linux SBC board to decode and play MP3s, from a USB stick and possible a network. I would also like it to have the facility for a small LCD to display details like Track Name.

Additionally, I would like it to be more of an art piece than an overpriced MP3 player. I would like to drive a surface of LEDs with various designs and patterns, essentially making it more of a visual design than a computer design.

I have found a few boards, but most lacked audio, so I suppose I would need to use an SPI interface or I2S to a DAC. A board with this already onboard would be nice. Furthermore, what would be the best way to drive the LED patterns? Could the GPIO's be used, or would an expansion board be better.

I am also alot more capable and familiar with FPGAs than embedded micro's, so any plausible solutions invnolving that would be nice as well. I really just want to learn, but would like to do it on the way to a project goal.

Cheers guys
Gints

You can look around at the "PC-104" format systems I guess, and maybe non-standard format boards; which one you choose depends on what you need. Just note - none of these are 'cheap'.

Some manufacturers which come to mind include:
WinSystems (www.winsystems.com)
TechnologicSystems (www.embeddedarm.com)
DSP Design (www.dspdesign.com)
Advantech (www.advantech.com.tw)

The first two are highly recommended, I haven't dealt with 'DSP Design' but I've been looking at their products, and I've found Advantech too frustrating to work with (maybe just crappy technical support here in Australia).

You might also want to have a look at the 'GumStix' computer, although I have no idea if it supports an LCD display.

As for those LCD displays - the multiline Alphanumeric displays come in models which use a serial port to set up the display - if that's the sort of LCD you have in mind. If you're thinking of the type used in PDAs, then you need a board which explicitly supports LCD displays - have a look at the "supported displays" if the manufacturer has such a list, then look at reviews of those particular displays.

Since you probably need buttons as well, you want support for a "keypad". You may need to write your own driver to scan the keypad, but sometimes the manufacturer provides a reference driver for Linux.

Have fun. :)

This SBC has built in audio. Not a lot of digital I/O but the board is easy to use.
http://www.jkmicro.com/products/omniflash.html

Hey guys,

Thanks for those links, I'll check them out. With regards to the LCD, all I was planning on was a quite minimalist 2 or 3 line display, not a coloured VGA display or anything.

Does anyone know as a general rule how much current these boards can sink through the I/O pins? I assume it would be very little...

You'll need to check the documentation for the board you're looking at. Some are "open collector" (or CMOS equivalent) buffers, some are "open emitter" buffers, some are unbuffered, some are 3.3v logic, some are 5v or 3.3 but 5v compatible ... the list goes on.

Since you want to use a simple alphanumeric LCD, I'd suggest looking at the LCD options first so you know you can pick a board which will support it.

I remember someone asking about embedded boards a few weeks ago and posting a link to a manufacturer in Israel which produced boards for about $60.

For power supplies, have a look at www.mini-box.com; they have great tiny switch-mode supplies.