Sunday, July 17, 2011

Hufiduino software update and new display

Hifiduino updated the software codes to version B09c, fixing some bugs and now my DAC can be controlled by a Apple remote control (only the volume & muting though).  The LCD displays a fresh look as shown in the photo below.  Uploading the program code is easy - via USB and using Arduino's own software and you can easily edit the codes to display the 'welcome screen' (when powered on) of your choice - for eg. your own name , etc.
When in use, the sampling rate (SR) is displayed to the last digit and is not 'rounded' to 100s, so you get figures like 44105 or 44095 (below) when playing 44.1kHz, which is acceptable considering it is only an error of 5Hz.  What I meant is you won't get exactly 44100, 88200, 96000 or 192000 on the display unless you change the software code to round off to the nearest 100.  Using different sources will result in slightly different figures but we don't know the actual absolute figure because there are many sources of error from the sources (cd player or Musiland) clocks error, Arduino clock error, the Buffalo clock error.  If all else remain constant, it can tell the relative clock rate of different sources (faster or slower by comparison only - not the true absolute clock rate). Sonically, the most important thing is the stability of the clocks - frequency drift (with time/temperature) and jitter. Unless we use a master word clock to synchronise all the clocks in the chain, or better still use atomic clock, maybe next time .........

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