ESP8266 Community Forum

- Wed Mar 04, 2015 10:12 pm #11335 Hi, Im having some trouble doing string matching for NEMA GPS codes. I am hitting the limit on string captures for this code.

the error: "too many captures"
Here is the code:

Code: Select allstr = "$GPRMC,005009.00,A,556.33250,N74137.05197,W,0.542,,050315,,,A*69"
time, status, latitude, ns_indicator, longitude,
        ew_indicator, speed, course, date, variation,
        ew_variation, checksum = string.match(str, "^%$GPRMC,([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^%*]*)(.*)$")
        print(longitude)

I think I can split it somehow, but im unsure if i can do it or how to do it.
I really only need the longitude and the latitude information but its nice to have the rest aswell.
If anyone knows how to solve my problem, please clue me in on how to fix it.

-Nick

- Sat Mar 07, 2015 2:19 am #11511 Use gmatch on ",([^,]*)" to loop through the matches, or split the match in two:

Code: Select allstr = "$GPRMC,005009.00,A,556.33250,N74137.05197,W,0.542,,050315,,,A*69"
time, status, latitude, ns_indicator, longitude,
        ew_indicator, rest = string.match(str, "^%$GPRMC,([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),([^,]*),(.*)$")
speed, course, date, variation, ew_variation, checksum = string.match(rest, "^([^,]*),([^,]*),([^,]*),([^,]*),([^%*]*)(.*)$")
        print(longitude)


- Sat Mar 07, 2015 9:47 am #11532 This works:

Code: Select allstr = "$GPRMC,005009.00,A,556.33250,N74137.05197,W,0.542,,050315,,,A*69"
a = string.gmatch(str,"(.-),")
print(a(1)) -- do something to junk the ones you don't want
time = a(1)
status = a(1)

...etc.

- Sat Mar 07, 2015 5:25 pm #11551 FYI

"$GPRMC,005009.00,A,556.33250,N74137.05197,W,0.542,,050315,,,A*69"

is not a valid GPRMC sentence
it should be

"$GPRMC,005009.00,A,556.33250,N,74137.05197,W,0.542,,050315,,,A*69"