• geiger counter pulse capture and graphing in Ubuntu?

    From Hem Jung@hemjA@netco.net to alt.os.linux.ubuntu on Fri Mar 26 14:01:37 2021
    From Newsgroup: alt.os.linux.ubuntu

    I was wondering if there were any -preferably free- programs that work
    under Ubuntu that capture pulses from the serial port produced by a
    geiger counter and can log and graph the data obtained? Thanks in advance
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  • From Paul@nospam@needed.invalid to alt.os.linux.ubuntu on Sat Mar 27 03:33:58 2021
    From Newsgroup: alt.os.linux.ubuntu

    Hem Jung wrote:
    I was wondering if there were any -preferably free- programs that work
    under Ubuntu that capture pulses from the serial port produced by a
    geiger counter and can log and graph the data obtained? Thanks in advance

    This looks as good a place to start, as any.

    http://www.noah.org/wiki/GM-45

    stty -F /dev/ttyUSB0 raw ispeed 57600 ospeed 57600 cs8 -ignpar -cstopb -echo
    while true; do read -n 1 serial_byte < /dev/ttyUSB0; date --utc "+%C%y-%m-%d %H:%M:%S UTC"; done

    The character value stored in "serial_byte" is being ignored.
    The "event" arriving is a pulse of a certain width. It
    does not matter what the character value is, because the
    character is just the downward-going pulse from the Geiger Muller tube.
    The character does not contain any intelligence. No processor
    made that character.

    Say for example, there are 10 gamma rays per second received
    by the GM tube. The time stamp output might look like...

    2021-03-26 17:38:20
    ... repeated nine more times
    2021-03-26 17:38:21
    ... repeated nine more times

    The temporal resolution is sufficient to calculate, in a
    round about way, that the rate is ten pulses per second.

    If this was my toy, I would bring in the signal on LineIn,
    using the 1/8" analog plug. The waveform recorded, might
    make it easier to understand what comes in via the RS232
    adapter. In terms of "timestamped events".

    Paul
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