I've got a modification to scopesink.py, gr_trigger_mode.h, and gr_oscope_guts.cc to allow viewing of an eye pattern. I added an "eye" trigger mode selection to the trigger menu, and an eye trigger mode that triggers on either a rising or falling edge (rather than only on one or the other). When the eye trigger mode is selected, the last 100 traces are displayed so the eye pattern can be viewed. Rather than setting the horizontal width by entering the number of samples per symbol, I just added some finer granularity to the scale selections for viewing my signal. I also added another state to the trigger detect in gr_oscope_guts.cc which looks for a "pre-trigger" when the eye trigger mode is selected. The LOOK_FOR_PRE_TRIGGER state looks for a rising or falling edge followed by 3/4 symbol time without a rising or falling edge. Only after this condition is met does it move to the LOOK_FOR_TRIGGER state.
The idea for this was that I wanted to trigger only on the transition within a manchester encoded symbol, and not on transitions between manchester encoded symbols (such as the transition between consecutive ones or zeros.) I'm thinking I might cut this pre-trigger state out of the my final version, since to evaluate the openness of the eye, there is really no difference between intra-symbol and inter-symbol edges. However, it might be useful as long as the delay (right now hard-coded to 3/4 my symbol time in samples) could be adjusted from the scope GUI in terms of samples. Anyone have any thoughts/preferences on this? Finally, after I finish tweaking this, what is the best way to submit the changes for evaluation and possible incorporation into the next release? Best regards, Jon -- This message was sent on behalf of [EMAIL PROTECTED] at openSubscriber.com http://www.opensubscriber.com/message/discuss-gnuradio@gnu.org/4721269.html _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
