diff options
| author | Keith Packard <keithp@keithp.com> | 2014-02-09 22:53:05 -0800 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2014-02-09 22:53:05 -0800 |
| commit | 5001a0f882af53dde33fc531215944c9d727baf4 (patch) | |
| tree | a78e1f00503df524680cd17d1a7ad8243a1db63f /src | |
| parent | 864d1e2282ac1d241478cf663ee24112c9d3dc37 (diff) | |
altos: Re-send previous GPS position in APRS if lock is lost
APRS radios often show only the last received APRS packet, which means
that erasing the last known GPS position when we lose lock by sending
0/0/0 is unhelpful. Instead, just send the last known position, and
make sure that we send 0/0/0 before we're locked the first time.
Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/drivers/ao_aprs.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c index c327c897..d472af4e 100644 --- a/src/drivers/ao_aprs.c +++ b/src/drivers/ao_aprs.c @@ -531,9 +531,10 @@ static int tncComment(uint8_t *buf) */ static int tncPositionPacket(void) { - int32_t latitude = 0; - int32_t longitude = 0; - int32_t altitude = 0; + static int32_t latitude; + static int32_t longitude; + static int32_t altitude; + int32_t lat, lon, alt; uint8_t *buf; if (ao_gps_data.flags & AO_GPS_VALID) { @@ -544,30 +545,29 @@ static int tncPositionPacket(void) altitude = 0; } - altitude = (altitude * (int32_t) 10000 + (3048/2)) / (int32_t) 3048; - buf = tncBuffer; *buf++ = '!'; /* Symbol table ID */ *buf++ = '/'; - latitude = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000; - longitude = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000; + lat = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000; + lon = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000; #define ALTITUDE_LOG_BASE 0.001998002662673f /* log(1.002) */ - altitude = logf((float) altitude) * (1/ALTITUDE_LOG_BASE); + alt = (altitude * (int32_t) 10000 + (3048/2)) / (int32_t) 3048; + alt = logf((float) altitude) * (1/ALTITUDE_LOG_BASE); - tncCompressInt(buf, latitude, 4); + tncCompressInt(buf, lat, 4); buf += 4; - tncCompressInt(buf, longitude, 4); + tncCompressInt(buf, lon, 4); buf += 4; /* Symbol code */ *buf++ = '\''; - tncCompressInt(buf, altitude, 2); + tncCompressInt(buf, alt, 2); buf += 2; *buf++ = 33 + ((1 << 5) | (2 << 3)); |