OPTION EXPLICIT
 OPTION AUTORUN ON
 
 CONST top1s=31   '16
 CONST cnbcde = 3
 CONST cnbch = 18
 CONST cnbbuf = 10
 CONST ccptvdg = 5  'comptage nb sec sans reception com
 
 CONST maxto = 500  'ex ime out 5 sec
 
 DIM i AS INTEGER
 DIM i1 AS INTEGER
 DIM i2 AS INTEGER
 DIM intCall AS INTEGER
 
 DIM tmcde(cnbcde) AS STRING LENGTH 3
 DIM nbcde AS INTEGER
 
 DIM tmgps(cnbcde,cnbch) AS STRING LENGTH 20
 DIM nbgps(cnbcde) AS INTEGER
 DIM ptcde AS INTEGER
 DIM ptgps AS INTEGER
 DIM flggps(cnbbuf) AS INTEGER
 
 DIM txcrc AS STRING
 DIM nbcar AS INTEGER
 
 DIM cptm3 AS INTEGER
 DIM cptvdg AS INTEGER
 DIM ptime1 AS FLOAT
 DIM ptime2 AS FLOAT
 DIM validgps AS INTEGER
 
 DIM tmbuf(cnbbuf) AS STRING
 DIM flgtmbuf(cnbbuf) AS INTEGER
 DIM ptWrite AS INTEGER
 DIM ptRead AS INTEGER
 DIM txbufgps AS STRING
 DIM txchamp AS STRING
 DIM flgf AS INTEGER
 
 
 i=0
 i=i+1:tmcde(i)="GGA"
 i=i+1:tmcde(i)="GSA"
 i=i+1:tmcde(i)="RMC"
 nbcde=i
 txbufgps=""
 flgf=0
 
 OPEN "COM1:9600,255,spcomrec4" AS #2
 ptWrite=0
 ptRead=0
 FOR i=1 TO cnbbuf
   tmbuf(i)=""
   flgtmbuf(i)=0
 NEXT i
 '*****************************
 DO
   ptime1=TIMER
   intCall = 0
   tfrgps
   ptime2=TIMER
   IF ptime2-ptime1>50 THEN
     PRINT TIME$;" ->";STR$((ptime2-ptime1)/1000,4,3);" ";STR$(intCall)
   END IF
   PAUSE(10)
 LOOP
 '*****************************
 
 
SUB tfrgps()  'store in database
 LOCAL txt AS STRING
 LOCAL flgg AS INTEGER
 FOR i=1 TO cnbbuf
   ptRead=ptRead+1
   IF ptRead>cnbbuf THEN ptRead=1
   IF flgtmbuf(ptRead)=0 THEN EXIT FOR
   IF flgtmbuf(ptRead)=2 THEN
     txt=tmbuf(ptRead)
     spgps(txt,flgg)
     IF flgg>0 THEN
       flgtmbuf(ptRead)=0
       calccrc2(txt)
       IF (validgps AND 16)=16 THEN
         rangegps(txt,flgg)
       END IF
     END IF
   END IF
 NEXT i
END SUB
 
SUB calccrc2(txc AS STRING)
 LOCAL jc AS INTEGER
 LOCAL ic AS INTEGER
 LOCAL i3 AS INTEGER
 jc=INSTR(txc,"*")
 IF jc>2 THEN
   ic=0
   FOR i3=2 TO jc-1
     ic=ic XOR ASC(MID$(txc,i3,1))
   NEXT i3
   'print
 END IF
 txcrc=HEX$(ic)
 IF LEN(txcrc)=1 THEN txcrc="0"+txcrc
 IF txcrc=RIGHT$(txc,2) THEN
   validgps=(validgps OR 16)
 ELSE
   validgps=(validgps AND &hEF )
   PRINT txc
   PRINT txcrc;"<>";RIGHT$(txc,2)
 END IF
END SUB
 
SUB spgps(txg AS STRING, ergp AS INTEGER)
 LOCAL i AS INTEGER
 ergp=0
 FOR i=1 TO nbcde
   IF MID$(txg,4,3)=tmcde(i) THEN  'for gps($gp) or glosnass($gn) frames
     ergp=i
     EXIT FOR
   END IF
 NEXT i
END SUB
 
SUB rangegps(txcrc AS STRING, flge AS INTEGER)
 LOCAL b$ AS STRING LENGTH 1
 IF LEFT$(txcrc,1)="$" THEN
   ptgps=0
   ptcde=flge
   txchamp=""
   FOR i2=1 TO LEN(txcrc)
     b$=MID$(txcrc,i2,1)
     IF b$="," THEN
       ptgps=ptgps+1
       tmgps(ptcde,ptgps)=txchamp
       txchamp=""
     ELSE
       IF ASC(b$)>31 THEN txchamp=txchamp+b$
     END IF
   NEXT i2
   ptgps=ptgps+1
   IF ptgps<=cnbch THEN
     tmgps(ptcde,ptgps)=txchamp
   END IF
   flggps(ptcde)=2
   nbgps(ptcde)=ptgps
 END IF
END SUB
 
 
SUB spcomrec4
 LOCAL tx$ AS STRING 'length 3
 LOCAL i1 AS INTEGER
 LOCAL i2 AS INTEGER
 LOCAL a$ AS STRING LENGTH 1
 LOCAL vai AS INTEGER
 intCall = intCall + 1
 i1=LOC(#2)
 IF i1=0 THEN
   EXIT SUB
 ELSE
   tx$=INPUT$(i1,#2)
   FOR i2=1 TO i1
     a$=MID$(tx$,i2,1)
     vai=ASC(a$)
     IF a$="$" THEN
       ptWrite=ptWrite+1
       IF ptWrite>cnbbuf THEN ptWrite=1
       tmbuf(ptWrite)=""
       flgtmbuf(ptWrite)=1
     END IF
     IF vai=10 THEN
       flgtmbuf(ptWrite)=2
     ELSE
       IF vai>31 THEN tmbuf(ptWrite)=tmbuf(ptWrite)+a$
     END IF
   NEXT i2
 ENDIF
 
END SUB