himbeermusik


My second attempt to build a music player thingy. Just about the same time I realized that I wasn't all that happy with my $file first try, I got a used HifiBerry DAC (for the 1st gen Raspberry) from a friend. Good thing I had the Pi from my $file first ARM based server idling around. And my old Amp (Rotel RA-921).
I didn't liked the idea to modify this amp, so I decided to build a simple Box for the Pi and DAC, slapping a few Buttons to it and a relay to control the Amp. Volume should be regulated via Software. That should give me plenty of time to procrastinate building another, final system.

Hardware

  • Raspberry Pi B (rev 2)
    • HifiBerry DAC
    • Rotary encoder
    • Two push buttons
    • Two LEDs
    • Relay + schuko plug adaptor
    • Cheap plastic case

So yeah, simple as Pi (pun intended). Well, mostly. The DAC is connected via the smaller, normally unpopulated second GPIO header of the Raspy rev 2. But it also populates the other GPIO Header (probably for structural support), which i need for other means. I made a simple adapter wire to connect the DAC to the second header without mounting it as intended to the pi. Frees up the GPIO header and eases the fitting in my small case.

Software


I wrote a simple (say: primitive) C-program using the wiringpi lib. This time I even managed to read the rotary encoder correctly. Finally. More later.
total: 58.85ms (include: 2.21, request: 0.87, trace: 0.44, init: 3.24, load: 0.01, parse: 49.58, menu: 0.84, template: 1.61, minify: 0.04)