Hi, the code on the wiki page doesn't look bad... keep on improving it :-) Regarding the problems with empty sentences - there are two possibilities: - check first whether the operation you're going to do is valid - thus you'll avoid exceptions - don't do the checks and catch exceptions in try-except blocks It's up to you which one you'll choose...
Martin On Fri, Mar 7, 2008 at 4:20 PM, Massimo Di Stefano <[EMAIL PROTECTED]> wrote: > hi Martin > > i'm doing something about gps signal acquisition, > > i wrote a initial script > to produce a gml from the nmea > it read the serial port where is connected the gps-receiver and write out to > gml format > > > http://wiki.gfoss.it/index.php/GPS_scrip_:_Parsing_del_segale_NMEA > > for now it is in "development" it is in a ugly form > (not well legible, i need to optimize its sintax, like adding > a dictionary to store the variables) > > it need an "excepition gestion" > beacouse if the nmea signal is low (or parts of it is empty) > the script exit ... and need to be reload. > > i haven't experience using "try" > mybe it could be a solution > ... i.e. if the signal is not good do : > sleep 0.5 > continue > ... and so on , until the nmea signal is readable > > in the loop i've : > > > while 1: > line = gps.readline() > datablock = line.split(',') > if line[0:6] == '$GPGGA': > ... > > #to manage the exception > #would be ??? : > > while 1: > try: > line = gps.readline() > datablock = line.split(',') > if line[0:6] == '$GPGGA': > #** except ... > sleep(0.5) > continue > quality = string.atof(datablock[6]) > ... > > if line[0:6] == '$GPGGA': > #** except ... > sleep(0.5) > continue > utctime = string.atof(datablock[1]) > ... > ... > > > i'll try to find how to manage the "try-except" statment > maybe it must controls the case where : > > - a specific datablock[] is empty or not a number > - the numbers of the needed params is less than nedded > > any suggestion, improvments, corrections are welcome > > regards, > > Massimo > > > > Il giorno 07/mar/08, alle ore 02:11, [EMAIL PROTECTED] ha > scritto: > On Thu, Mar 6, 2008 at 9:36 PM, victor javier morales > <[EMAIL PROTECTED]> wrote: > > I think the same of you martin, but > the real problem is that we don't know How this machines deliver their data, > for example the format for this data or the speed in real time. > > > The data formats sent by GPS are usually well-documented, moreover > there is a de facto standard NMEA-0183 which is used by majority of > GPS producers. > > Martin > > _______________________________________________ > Qgis-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-user > > _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
