New topic: Serial port programming
<http://forums.realsoftware.com/viewtopic.php?t=37730> Page 1 of 1 [ 1 post ] Previous topic | Next topic Author Message Talisker Post subject: Serial port programmingPosted: Sat Feb 19, 2011 5:26 am Joined: Tue Jul 27, 2010 4:27 am Posts: 5 Hi Guys, I am looking for some divine guidance. The situation is, I have got a serial port listening to the output of NMEA sentences from a GPS. And with my limited programming experience, have got the program to write what it gets to a textarea. The GPS streams data to the serial port at 4800 baud and repeats every 2 seconds, each set of sentences are about 940 bits, so there is only a few microseconds before the next set arrive. This system is purely data in and data out, so the handshaking is dealt with loopbacks. My problem is, how can I cut into this stream of data to process the information I am getting? For those who have no idea what NMEA sentences look like, here is an example! $GPRMC,080935,A,3512.589,N,08449.304,W,000.0,360.0,230806,004.1,W*79 $GPRMB,A,,,,,,,,,,,,V*71 $GPGGA,080935,3512.589,N,08449.304,W,1,08,2.0,311.4,M,-31.4,M,,*76 $GPGSA,A,3,02,,06,,10,18,21,26,,29,30,,3.2,2.0,3.0*31 $GPGSV,3,1,11,02,29,090,42,05,03,202,00,06,53,297,46,08,00,074,00*7E $GPGSV,3,2,11,10,53,036,46,18,10,239,34,21,15,294,37,26,42,159,45*7D $GPGSV,3,3,11,27,00,048,00,29,51,146,46,30,16,237,37,,,,*48 $PGRME,15.0,M,22.5,M,15.0,M*1B $GPGLL,3512.589,N,08449.304,W,080935,A*38 $PGRMZ,1021,f,3*29 $PGRMM,WGS 84*06 $GPBOD,,T,,M,,*47 $GPRTE,1,1,c,0*07 And this repeats every 2 seconds. If I start the program after the GPS, then the serial port cuts in anywhere in the data. If I start the program first I get the first sentence beginning with "$GPRMC". Any thoughts? Steve Top Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending Page 1 of 1 [ 1 post ] -- Over 1500 classes with 29000 functions in one REALbasic plug-in collection. The Monkeybread Software Realbasic Plugin v9.3. http://www.monkeybreadsoftware.de/realbasic/plugins.shtml [email protected]
