lets see, on top in green is a 328 ard with an ethernet shield (wiznet in red) being a web client to the MPD music playback daemon that runs on my linux box. it accepts IR commands from a sony dvd player remote and lets you pause, play, skip back/forward and also see the song that's currently being played. its at a very basic 0.1 functionality level but the proof-of-concept at least does work.
to the right, in orange, is a DIY spdif coax/opto switch. also uses the same IR control and a 168 atmel chip to switch one of 4 digital audio inputs to a pair of coax/opto outputs. it also has an rgb user color settable backlight
the larger 1U box on the bottom is running a boarduino and an orange transmissive lcd (255 step dimmable) that controls my volume control chip (burr brown pga23xx series) and also has an x10 firecracker wireless transmitter to relay-control my amps and other x10 power-line devices.
all 3 use the sony IR remote (sample code from the net) and basically they pretty much replace the yamaha home stereo that I once had
they all run my code base (VoluMaster is what I'm calling it). I plan to release schematics and code once things are final and working the way I want (and integrated with each other in the right ways).
start to finish - including learning the arudino concepts and building all these things by hand - took about 3 weeks. they are essentially my first controller projects.
the black plastic cuts just by looking at it, so its not hard. its soft plastic that you can use a nibbling tool (once you drill a round hole large enough to start with) and just nibble until you are close enough. then its file tool or maybe xacto knife if you need to cut bigger chunks.
for metal, its just a lot of work if using hand tools (me) and so I avoid it. one chassis was metal but I try to use this non-splinter non-cracking plastic stuff at my plastic store (TAP). the crinkle finish helps hide a lot of 'hardware overruns' (lol) too.
as for the LCDs, all came from mouser but Ii think digikey has most of them as well. the rgb backlight is JUST a tricolor 4 wire led stuck in sideways in a diffuser. for that its $4 more
I can't find rgb backlit 20x4 displays - only 16x2. the music player app really screams out for a larger display so I'd like to get a 4x20 one and I'd like it to have the rgb backlight as well. but I do NOT like paying $70 for them! ;(
its nearly complete, now. it is still polling based (every 3 or 4 secs it web-connects and gets data then parses it and displays only what changed to the lcd).
eventually I'll lay out the code better so that its mostly or even entirely interrupt based. so until then, the IR commands from the user sometimes seem sluggish to be recognized.
I have my bargraph code ported over from my VoluMaster code base and now I can see song progress (lol) on the display.
I have a new LARGE lcd 4x20 display now. regular 16 pin interface - but WOW is it large. $35 at mouser. I had no idea what I was ordering until it got here in the mail
contrast seems to be a fixed pot thing for most designs I've seen. it does not like pwm (directly) for contrast. so I'll do the same, just let contrast be a small rail-to-rail pot with the wiper being the contr. pin. its a set-and-forget thing unless you change view angle a lot.
backlight is 1 pwm pin, direct, with a small series R but very small (less than 100ohms).
however, with 3 backlight leds (rgb, on some displays) you need 3 pwm pins!
and things get harder, too, with rgb. dimming is trivial with 1 color but dimming with 3 colors and keeping the color mostly the same and varying only its luma? not easy not rocket science but not a simple for-loop either.
also, the pwm dimming is not linear so you need to have smaller steps at lower numbers (where the display is almost off) than at the top where yo can vary by 10 counts and still not see much dimming effect.
also, the pwm dimming does NOT seem to seep into the audio chain! that was a worry of mine. I did an rmaa test and the pga chip and display all seemed to be almost the same as the base noise level of the sound card test system, itself (m-audio firewire).
I'm glad we're WAY beyond the EL backlights and hummy/whinny inverters. this takes just 3 v for the leds and has no inverter or high voltage needed!
yes, the info is live, real, from ethernet and mpd.
I have a slightly hacked mpd php script that returns 'simple' format instead of the verbose html that mpd/php want to normally return.
I cut the i/o down from a few hundred bytes (or more) to a line or 2 of text and no more. it makes the parsing much easier if I don't have to skip over html tags just to get the id3 song info.
All of this would work out awesome for retro-fitting an antique radio, since it's in small components and can be made to fit a particular design. Finding a way to intergrate or hide the LCD might be an interesting challenge too.
Hi Linux-works.
I'm a fellow audio guy from Headfi.
How does the audio part work?
Did you do it with the arduino, or is there somethin else involved.
Would be awesome to have a arduino controlled mpd player that outputs spdif or i2s. If you already did that, great :).