uint32_t GPS_coord_to_degrees(char* s) {
char *p, *q;
uint8_t deg = 0, min = 0;
unsigned int frac_min = 0;
uint8_t i;
// scan for decimal point or end of field
for (p = s; isdigit(*p); p++) ;
q = s;
// convert degrees
while ((p - q) > 2) {
if (deg)
deg *= 10;
deg += DIGIT_TO_VAL(*q++);
}
// convert minutes
while (p > q) {
if (min)
min *= 10;
min += DIGIT_TO_VAL(*q++);
}
// convert fractional minutes
// expect up to four digits, result is in
// ten-thousandths of a minute
if (*p == '.') {
q = p + 1;
for (i = 0; i < 4; i++) {
frac_min *= 10;
if (isdigit(*q))
frac_min += *q++ - '0';
}
}
return deg * 10000000UL + (min * 1000000UL + frac_min*100UL) / 6;
}
u32 GPS_Coord_to_Degrees(char *s)
{
char *p,*q;
u8 deg = 0,min = 0;
u32 frac_min = 0;
int i;
for(p=s;isdigit(*p);p++); //让p指向?ddmm.mmmmm字符串的点
q = s;
while((p - q) > 2) //将度（即那个dd喽）提取出来，保存在deg
{
if(deg)
deg*=10;
deg += DIGIT_TO_VAL(*q++);
}
while(p > q) //将那个点前面的分提取出来，即分的整数部分
{
if(min)
min*=10;
min += DIGIT_TO_VAL(*q++);
}
if(*p == '.') //将分小数部分提取出来
{
q = p + 1;
for(i = 0;i < 4; i++)
{
frac_min *= 10;
if(isdigit(*q))
frac_min += *q++ - '0';
}
}
//ddmmmmmmm
return deg * 10000000UL + (min * 1000000UL + frac_min * 100UL) / 6;//10000000表示1度，这样分辨率刚好是1cm，虽然这是不精确的
}
static uint32_t GPS_coord_to_degrees(char* s)
{
char *p, *q;
uint32_t deg = 0, min = 0, frac_min = 0, i;
for (p = s; isdigit((unsigned char)*p); p++); // scan for decimal point or end of field
q = s;
while ((p - q) > 2) // convert degrees
{
if (deg) deg *= 10;
deg += DIGIT_TO_VAL(*q++);
}
while (p > q) // convert minutes
{
if (min) min *= 10;
min += DIGIT_TO_VAL(*q++);
}
if (*p == '.') // convert fractional minutes expect up to four digits, result is in ten-thousandths of a minute
{
q = p + 1;
for (i = 0; i < 4; i++)
{
frac_min *= 10;
if (isdigit((unsigned char)*q)) frac_min += DIGIT_TO_VAL(*q++);
}
}
return deg * 10000000UL + (min * 1000000UL + frac_min * 100UL) / 6;
}
uint32_t AP_GPS_NMEA::_parse_degrees()
{
char *p, *q;
uint8_t deg = 0, min = 0;
unsigned int frac_min = 0;
int32_t ret = 0;
// scan for decimal point or end of field
for (p = _term; isdigit(*p); p++)
;
q = _term;
// convert degrees
while ((p - q) > 2) {
if (deg)
deg *= 10;
deg += DIGIT_TO_VAL(*q++);
}
// convert minutes
while (p > q) {
if (min)
min *= 10;
min += DIGIT_TO_VAL(*q++);
}
// convert fractional minutes
// expect up to four digits, result is in
// ten-thousandths of a minute
if (*p == '.') {
q = p + 1;
for (int i = 0; i < 5; i++) {
frac_min = (int32_t)(frac_min * 10);
if (isdigit(*q))
frac_min += *q++ - '0';
}
}
ret = (int32_t)deg * (int32_t)1000000UL + (int32_t)((min * 100000UL + frac_min) / 6UL);
return ret;
}
uint32_t GPS_coord_to_degrees(const char* coordinateString)
{
const char *fieldSeparator, *remainingString;
uint8_t degress = 0, minutes = 0;
uint16_t fractionalMinutes = 0;
uint8_t digitIndex;
// scan for decimal point or end of field
for (fieldSeparator = coordinateString; isdigit((unsigned char)*fieldSeparator); fieldSeparator++) {
if (fieldSeparator >= coordinateString + 15)
return 0; // stop potential fail
}
remainingString = coordinateString;
// convert degrees
while ((fieldSeparator - remainingString) > 2) {
if (degress)
degress *= 10;
degress += DIGIT_TO_VAL(*remainingString++);
}
// convert minutes
while (fieldSeparator > remainingString) {
if (minutes)
minutes *= 10;
minutes += DIGIT_TO_VAL(*remainingString++);
}
// convert fractional minutes
// expect up to four digits, result is in
// ten-thousandths of a minute
if (*fieldSeparator == '.') {
remainingString = fieldSeparator + 1;
for (digitIndex = 0; digitIndex < 4; digitIndex++) {
fractionalMinutes *= 10;
if (isdigit((unsigned char)*remainingString))
fractionalMinutes += *remainingString++ - '0';
}
}
return degress * 10000000UL + (minutes * 1000000UL + fractionalMinutes * 100UL) / 6;
}
