Comedi Record


What is it?

comedirecord is an oscilloscope program to display and record data from a COMEDI device. Its philosophy is to save the data in its original form at the set sampling rate but allows comfortable viewing of the data during an experiment. Viewing is graphical but the parameters are set via the commandline.

Notch, lowpass, highpass and DC filters have been implemented to improve the viewing experience. Their parameters can be changed via the commandline.

You can check the frequency spectrum of one channel with the option "-x"

The output format is ASCII. The data can be imported into GNUPLOT, scilab or octave. The first column is the sample number (RAW on) or the time in seconds (RAW off). The next columns represent the (raw/physical) data from the comedi device.


A quick guide how to import the data into GNU's octave or MATLAB

This code fragment imports the data file "myname5.dat" into the variables x and t

  1. load myname5.dat
  2. x=myname5(:,2); % data
  3. t=myname5(:,1); % time
  4. plot(x);
  5. plot(abs(fft(x)));

...and a quick guide how to import the data into scilab

  1. -->ecg=read('long_ecg.dat',-1,2); % loads the first two columns
  2. -->y=ecg(:,2); % get the data
  3. -->plot(y);


Bernd Porr