An oscilloscope program for COMEDI
comedirecord is a simple program to record data from a comedi device and write the data to a file. Its philosophy is not to alter the data which is written to the hard drive but allowing flexible monitoring of the data, for example during an experiment. Data is always saved at the maximum sampling rate (default 1kHz but can be changed with the "-r" parameter) and unfiltered in a Python-friendly format.
It has been designed for the USB-DUX sigma board but it should also run with other daq boards supported by comedi. The number of channels is set to the maximum number possible but can be changed by the commandline parameter -c to increase the overall sampling rate.
A IIR notch filter has been implemented to filter out unwanted hum from the mains. This might be useful for medical applications. Default is 50Hz but can be changed via command line parameter -n.
The data is written out as an ASCII file and is always unfiltered and at the max internal sampling rate.
Additional data from another program can be appended to the data file via a socket connection. comedirecord acts as the server and the other application is its client. The port number can be specified with the -p option and then comedirecord waits until a client connects to it. You can test it with: "comedirecord -p 65000" and then "telnet localhost 65000".
The data can be imported into GNUPLOT, python or octave. The first column is the sample number or time in secs. The next columns represent the (raw/phys) data from the comedi device.
https://github.com/berndporr/iir1
Install the required packackes:
sudo apt install libqwt-qt5-dev libfftw3-dev libcomedi-dev qtbase5-dev qt5make
cmake .
make
Test it locally if it runs with:
./comedirecord
sudo make install
which installs it in /usr/local/bin.
After the global install type into the terminal:
comedirecord