diff options
| author | Keith Packard <keithp@keithp.com> | 2012-12-16 13:29:31 -0800 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2012-12-16 13:29:31 -0800 |
| commit | 6b4cfd8719e3fd4a2904369e176182c870a3b43c (patch) | |
| tree | 72f419f8b3be7359577aa63817f870e0e3630281 | |
| parent | cf47efdc86f0b421fcf4389669fbecf6fa3f5934 (diff) | |
altos: Round APRS data correctly
Apply rounding once at the start of the computation, then truncate
after that.
Signed-off-by: Keith Packard <keithp@keithp.com>
| -rw-r--r-- | src/drivers/ao_aprs.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c index 93c4af3f..03bcab05 100644 --- a/src/drivers/ao_aprs.c +++ b/src/drivers/ao_aprs.c @@ -507,24 +507,32 @@ static int tncPositionPacket(void) longitude = -longitude; } + /* Round latitude and longitude by 0.005 minutes */ + latitude = latitude + 833; + if (latitude > 900000000) + latitude = 900000000; + longitude = longitude + 833; + if (longitude > 1800000000) + longitude = 1800000000; + lat_deg = latitude / 10000000; latitude -= lat_deg * 10000000; latitude *= 60; lat_min = latitude / 10000000; latitude -= lat_min * 10000000; - lat_frac = (latitude + 50000) / 100000; + lat_frac = latitude / 100000; lon_deg = longitude / 10000000; longitude -= lon_deg * 10000000; longitude *= 60; lon_min = longitude / 10000000; longitude -= lon_min * 10000000; - lon_frac = (longitude + 50000) / 100000; + lon_frac = longitude / 100000; if (altitude < 0) altitude = 0; - altitude = altitude * (int32_t) 1000 / (int32_t) 3048; + altitude = (altitude * (int32_t) 10000 + (3048/2)) / (int32_t) 3048; return sprintf ((char *) tncBuffer, "=%02u%02u.%02u%c\\%03u%02u.%02u%cO /A=%06u\015", lat_deg, lat_min, lat_frac, lat_sign, |