28-dec-05: after the jukebox already worked fairly good (even IR-remote via lirc), i decided to change it completely. The Samsung 80GB harddisk is very quiet, but when listening
to classical music in a very low noise enviroment some higher frequency noise is audible. The new version will boot from a 128mb CF-Card and access a smb
network storage system (landrive without the harddisk 70eur at ebay).
read Linux on CF
The old IR and display-board, removed from a old satellite-receiver. The Display lights up but isn't used for anything.
20-jul-05: plugin_asciifile.c for lcd4linux works basically, it will show the first line of an plain ascii-file on the
lcd. i dont know anything about cvs and gnu, i will have to learn about it on the web, so the plugin wont be available
too soon. the mpd client writes to the same file at runtime. to have this working with songtitle and so on, i will have to program
a lot more string-handling. the heatsink of the +5v rectifier schottky-diodes in the powers-supply gets a little hot for my opinion, i will have to
change this too.
lcd4linux in action
18-jul-05: got an maudio dio 24/48 on ebay. looked at the alsa homepage for drivers, and the forum right there looks like this
wont be a plug and play solution, but i'm willing to take that risk, because i want to go for a real high end version with external
d/a converters. the behringer ultracurve 24/96 looks fine...
8-apr-05: lcdproc still won't work, my testprogram is far too slow, i can watch each letter appear on the display...
lcd4linux works fine, i will have to write a plugin for that. ipc under linux, not exactly trivial :)
6-feb-05: I finally got the lcd ( PVG 240060 , based on the t6963 controller) to work ! Because the linux program lcdproc did not work,
i started testing it under w2k. To control the parallel port directly in c, you need inpout32.dll. After some hours without success, i found out that one of the pins on the
display labeled "no connection" in my first pinout-paper has to be connected to the negative voltage output of the display,
using a pot to adjust contrast.
Unfortunately it still doesnt work with lcdproc, so that i will write my lcd-daemon by myself too.
You may have a look at the source-code of the win2k testprogram
; i use lcc32
A standalone Linux-Jukebox
The idea to this arose with the 10th audio cdr being unreadable by my Sony Hifi Cd-Player.
I learned about flac, a lossless codec for audio, that will compress by ~50%, for classical
program even by 75%. Lossless means, there is no quality lost as with mp3, ogg or musepack. If
you decompress the content, it will be identical to the source.
If you like classical music and expensive headphones, dont even think about mp3, ogg or anything lossy :)
So my Jukebox is supposed to
- fit in my hifi-rack and look like a normal hifi-component
- play definitly flac, mp3, ogg vorbis
- play mpc, aac ... would be nice
- host a >=80 Gb harddisk
- boot up in clearly less than a minute
- be accesable via LAN
- be completely fan-less
- work without monitor, mouse, computer-style keyboard
Because i had several socket 7 boards still laying around, i decided to use one of those.
I lost my nerves on linux some time ago, so i tried a win95/winamp combination, running on
a amd k6/233 at 166mhz, at full 3.3v , because on this board it was impossible to change
the cpu voltage by hand. To monitor the temperature of the cpu, i modified the heatsink by
attaching a sensor element close to the base of the cooler. Showing a resistance of about
1200 ohms at room temperature, the resistance would drop with increasing temperature (ntc).
Lately i measured the resistance of those ntc's at 100c° (boiling water), it was around 80 ohms.
On the first mainboard i had 705 ohms at full speed and voltage (233mhz/3.3v) and the cpu-fan
at full speed (12v) too.
By the way, current consumption of the board at this state was ~5 amps (5v) and 0.2 amps (12v).
But even with this "naked" win95 booting would take forever and a day. At 166mhz i had dropouts on
ogg vorbis tracks too.
The Linux system however, would boot much faster, and for that reason i came back to Linux again.
I first tried Core Linux, because its slim and supposed for such embedded applications, now
i tested DSL, which took much longer to boot from cd or hd, now i'am back with Core
I tested xmms under x-windows, but then i read about MPD, which would run without x-windows. To control MPD, you need a client, many are available, but most of them are designed to
control MPD from a remote pc via tcp/ip. To control it from the same pc, via keys but not a complete keyboard (mostly the number keys), without a monitor, i decided to write my own client.
An old 150 W power-supply, getting only handwarm without the fan
Current boot-up time (power switch pressed till first tone) : 27 seconds (31.jan.2005)