Loading ...
Sorry, an error occurred while loading the content.
 

Need lookup table or function, or ??

Expand Messages
  • boblarkin02
    I m working with Mike, KD7TS, on a transmit/receive system for VHF amateur frequencies. As part of this we need to randomize the frequency (over perhaps 50
    Message 1 of 2 , Dec 29, 2012
      I'm working with Mike, KD7TS, on a transmit/receive system for VHF amateur frequencies. As part of this we need to randomize the frequency (over perhaps 50 Hz) from minute to minute, and have the same answer in SL running at both ends.

      The DSP-10 system we are mimicking does this with a lookup table containing 1440 pseudo random numbers. Alternate systems would be a generating function running in SL, since we don't need the exact same table or an exec procedure to leave the current number in a file (or otherwise transfer it back to SL).

      I have not found a way to use a 1440 entry lookup table directly in SL.

      I have not been able to come up with a good algorithm for a generating function, short of running a random number generator up to 1440 times. Or reseeding a generator with the minute, with a resulting periodic pattern to the numbers.

      I have not found a way to transfer a result from an "exec" program, running once per minute, back to SL.

      Anyone have any ideas? Thanks in advance.

      Bob W7PUA
    • wolf_dl4yhf
      Hello Bob, I don t think there is an easy solution at the moment - the only method to pass the result from an external program would be to place data in a
      Message 2 of 2 , Dec 31, 2012
        Hello Bob,

        I don't think there is an easy solution at the moment - the only method to pass the result from an external program would be to place data in a file, which can then be loaded by SL.
        But doing this with the command interpreter's current instruction set (using conditional actions, etc) would be painful, since it lacks generic file access methods, flow control commands (like if-then-else, for-to, repeat-until, etc etc). I considered integrating a kind of 'programming language', which I wrote for a completely different project (actually a programmable logic controller), in Spectrum Lab. But this would take a lot of time -which I don't have at the moment- so the best you can do at the moment is implement the frequency-calculation in an external programming language (possibly Javascript running in a web browser), and exchange data with Spectrum Lab through its integrated tiny web server (you can invoke commands in SL from Javascript as explained somewhere in the manual).


        Happy new year,
          Wolf .

        Am 29.12.2012 23:36, schrieb boblarkin02:
         

        I'm working with Mike, KD7TS, on a transmit/receive system for VHF amateur frequencies. As part of this we need to randomize the frequency (over perhaps 50 Hz) from minute to minute, and have the same answer in SL running at both ends.

        The DSP-10 system we are mimicking does this with a lookup table containing 1440 pseudo random numbers. Alternate systems would be a generating function running in SL, since we don't need the exact same table or an exec procedure to leave the current number in a file (or otherwise transfer it back to SL).

        I have not found a way to use a 1440 entry lookup table directly in SL.

        I have not been able to come up with a good algorithm for a generating function, short of running a random number generator up to 1440 times. Or reseeding a generator with the minute, with a resulting periodic pattern to the numbers.

        I have not found a way to transfer a result from an "exec" program, running once per minute, back to SL.

        Anyone have any ideas? Thanks in advance.

        Bob W7PUA


      Your message has been successfully submitted and would be delivered to recipients shortly.