It took one night of hardcore hacking, and it works nicely :-) Thanx Psy. I used: * an Arduino Uno (clone) * 2x Sure Electronics [[http://www.sureelectronics.net/goods.php?id=1122|DE-DP14211]] * HT1632c library [[http://code.google.com/p/ht1632c/source/browse/|Code by wildstray]] * Fast Fourier Transformation library [[http://code.google.com/p/makefurt/source/browse/trunk/arduino-libraries/FixFFT/|Code by #makefurt]] Here is a write-up of the [[projects:spectrumanaliser:step1_hardware|hardware]]. And a short note on the [[projects:spectrumanaliser:step2_software|software]].