diff options
| -rw-r--r-- | libraries/TinyGPS/TinyGPS.cpp | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/libraries/TinyGPS/TinyGPS.cpp b/libraries/TinyGPS/TinyGPS.cpp index 5a5b86b..c45ed19 100644 --- a/libraries/TinyGPS/TinyGPS.cpp +++ b/libraries/TinyGPS/TinyGPS.cpp @@ -66,7 +66,7 @@ bool TinyGPS::encode(char c) switch(c) { case ',': // term terminators - _parity ^= c; + _parity ^= ','; case '\r': case '\n': case '*': @@ -93,7 +93,7 @@ bool TinyGPS::encode(char c) if (_term_offset < sizeof(_term) - 1) _term[_term_offset++] = c; if (!_is_checksum_term) - _parity ^= c; + _parity ^= (byte)c; return valid_sentence; } @@ -110,7 +110,7 @@ void TinyGPS::stats(unsigned long *chars, unsigned short *sentences, unsigned sh // // internal utilities // -int TinyGPS::from_hex(char a) +byte TinyGPS::from_hex(char a) { if (a >= 'A' && a <= 'F') return a - 'A' + 10; @@ -120,6 +120,29 @@ int TinyGPS::from_hex(char a) return a - '0'; } +byte TinyGPS::hex2uint8(const char *p) +{ + byte c1 = *p; + byte c2 = *(p + 1); + if (c1 >= 'A' && c1 <= 'F') + c1 -= 7; + else if (c1 >= 'a' && c1 <= 'f') + c1 -= 39; + else if (c1 < '0' || c1 > '9') + return 0; + + if (c2 == 0) + return (c1 & 0xf); + else if (c2 >= 'A' && c2 <= 'F') + c2 -= 7; + else if (c2 >= 'a' && c2 <= 'f') + c2 -= 39; + else if (c2 < '0' || c2 > '9') + return 0; + + return c1 << 4 | (c2 & 0xf); +} + unsigned long TinyGPS::parse_decimal() { char *p = _term; @@ -165,7 +188,7 @@ bool TinyGPS::term_complete() { if (_is_checksum_term) { - byte checksum = 16 * from_hex(_term[0]) + from_hex(_term[1]); + byte checksum = hex2uint8(_term); if (checksum == _parity) { if (_gps_data_good) |