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sdk:gps-udp-client-gnsstogps [2019/07/09 13:49]
fachet
sdk:gps-udp-client-gnsstogps [2021/10/08 10:22] (current)
dodenhoeft [SDK Script gps-udp-client-GNSStoGPS.are]
Line 1: Line 1:
 +====== Background ======
 +GPS was the first Global Navigation Satellite System (GNSS) and the term GPS is often used as a synonym for GNSS.
 +
 +Older software often only checks for NMEA 0183 sentences starting with <​nowiki>"​$GP"</​nowiki>​ (= GPS only) instead of looking for  all GNSS systems.
 +
 +Newer GNSS receivers often use multiple GNSS systems and therefore <​nowiki>"​$GN"</​nowiki>​ is used (<​nowiki>"​$GNRMC..."</​nowiki>​) if it recives a combination of GPS, Galileo and GLONASS signals.
 +
 +It would be better to us instead of <​nowiki>"​$GPRMC"</​nowiki>​ either <​nowiki>"​$G.RMC"</​nowiki>​ ("​."​ = anychar) for using GPS, Galileo and/or GLONASS (GNSS) or even <​nowiki>"​$..RMC"</​nowiki>​ which means any source.
 +
 +<​code>​
 +NMEA 0183 sentence "​$XXYYY..."​ explanation:​
 +
 +"​$"​ = Start 
 +"​XX"​ = Source device (https://​de.wikipedia.org/​wiki/​NMEA_0183#​Ger%C3%A4te-IDs)
 + BD = Beidu
 + GA = Galileo
 + GL = GLONASS
 + GP = GPS
 + GN = GNSS position fix from more than one constellation (eg. GPS + GLONASS)
 +"​YYY"​ = Record
 + RMC = Recommended Minimum Sentence C (used in most cases)
 + GGA = Global Positioning System Fix Data
 + GNS = GNSS fixed data
 + GLL = Geographic Position - Latitude/​Longitude
 + ...
 +
 +Source: https://​de.wikipedia.org/​wiki/​NMEA_0183
 +</​code>​
 +
 ====== SDK Script gps-udp-client-GNSStoGPS.are ====== ====== SDK Script gps-udp-client-GNSStoGPS.are ======
 <code c gps-udp-client-gnsstogps.are>​ <code c gps-udp-client-gnsstogps.are>​
Line 23: Line 52:
  
  nb_config_set("​gpsd.0.status=0"​);​  nb_config_set("​gpsd.0.status=0"​);​
- sleep(3);+                do { 
 +                                ​sleep(3); 
 +                } while ( nb_config_done() != 0) 
 +     
  nb_config_set("​gpsd.0.status=1"​);​  nb_config_set("​gpsd.0.status=1"​);​
- sleep(5); +                do { 
 +                 ​sleep(5); 
 +                } while ( nb_config_done() != 0)
  return 0;  return 0;
 } }
- 
 int gpsd_connect () int gpsd_connect ()
 { {
Line 39: Line 71:
  exit(-1);  exit(-1);
  }  }
- for (attempt = 0; attempt <= 5; attempt++) { + for (attempt = 0; attempt <= 15; attempt++) { 
- sleep(3);+ sleep(15);
  
  if (connect(gpsd,​ local_ip, local_port) < 0) {  if (connect(gpsd,​ local_ip, local_port) < 0) {
  nb_syslog("​Could not connect to daemon"​);​  nb_syslog("​Could not connect to daemon"​);​
- if (attempt == 3) {+ if (attempt == 12) {
  nb_syslog("​Unable to connect, restarting daemon"​);​  nb_syslog("​Unable to connect, restarting daemon"​);​
  gpsd_restart();​  gpsd_restart();​
Line 70: Line 102:
  chars = explode(s);  chars = explode(s);
         for (i = 1; i < pos; i++) { /* skip $ and *XX */          for (i = 1; i < pos; i++) { /* skip $ and *XX */ 
-     ​printf("​ %s ", chars[i]);​ +     c = ord(chars[i]);​
-            ​c = ord(chars[i]);​+
             cs ^= c;             cs ^= c;
         }         }
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  a_arr = explode(data);​  a_arr = explode(data);​
  a_arr[2] = "​P";​  a_arr[2] = "​P";​
- data = implode(a_arr);​+ data = checksum(implode(a_arr));
  }  }
  /* skip all messages different from GPGGA   /* skip all messages different from GPGGA