Soundcard Scope – My computer is my oscilloscope

I really wanted an oscilloscope for debug of signals which I was sampling
on Galileo IO and came across this wonderful software Soundcard Scope –
by an amazing Christian Zeitnitz.

The software simply transformed my computer into an oscilloscope. It uses
the mic input to sample signals as if they are sound signals and plots it
for visual debug like an oscilloscope. The software uses the sound card’s
44KHz sampling frequency and if you have signals just below 20KHz, this
is a perfect DIY at home scope for makers. I don’t own a regular scope but
would guess them to be pricey enough to be NOT that affordable. Though this
is not a replacement for a regular scope, it sure is a feat for some one
wanting to just get a glimpse of those electrical signals and feel happy
about the wiggles!!
Oscilloscope
Sure it was a bit noisy but seeing those signals wiggle makes one feel like
a winner!

Connections for the mic also attached.
mic35
The software itself is a Windows executable. But then I have Debian wheezy.
I installed Wine and could run this Windows executable like a charm first
time. I tried to create a make-shift mic in cable with one of the spare
3.5mm jacks that I got for to make the USB to ttySerial serial cable for
my Galileo.

Worked pretty well! Have a look in the picture below – The breadboard has
a TSOP IR decoder decoding IR streams. Output of the TSOP is fed to the
Galileo as well as the mic in of my computer – and screen shows a nice
waveform. The IR decoded pulses are supposed to be 600us wide so my
waveform would be around 1.6kHz which should fall well within the range
for this scope.

PS: The Galileo still reads a different value as compared to what I see on the
scope though.
Mic diagram from http://www.epanorama.net/

Cheers!
/G

[experience dated Aug 2014]

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