diff options
Diffstat (limited to 'src/drivers/ao_aprs.c')
| -rw-r--r-- | src/drivers/ao_aprs.c | 113 |
1 files changed, 66 insertions, 47 deletions
diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c index 6ab61e6a..56d98437 100644 --- a/src/drivers/ao_aprs.c +++ b/src/drivers/ao_aprs.c @@ -144,6 +144,7 @@ #endif #include <ao_aprs.h> +#include <math.h> // Public methods, constants, and data structures for each class. @@ -254,9 +255,9 @@ typedef enum /// AX.25 compliant packet header that contains destination, station call sign, and path. /// 0x76 for SSID-11, 0x78 for SSID-12 static uint8_t TNC_AX25_HEADER[] = { - 'A' << 1, 'P' << 1, 'A' << 1, 'M' << 1, ' ' << 1, ' ' << 1, 0x60, \ - 'N' << 1, '0' << 1, 'C' << 1, 'A' << 1, 'L' << 1, 'L' << 1, 0x78, \ - 'W' << 1, 'I' << 1, 'D' << 1, 'E' << 1, '2' << 1, ' ' << 1, 0x65, \ + 'A' << 1, 'P' << 1, 'A' << 1, 'M' << 1, ' ' << 1, ' ' << 1, 0x60, + 'N' << 1, '0' << 1, 'C' << 1, 'A' << 1, 'L' << 1, 'L' << 1, 0x78, + 'W' << 1, 'I' << 1, 'D' << 1, 'E' << 1, '2' << 1, ' ' << 1, 0x65, 0x03, 0xf0 }; #define TNC_CALLSIGN_OFF 7 @@ -479,6 +480,36 @@ static void tnc1200TimerTick() } // END switch } +static void tncCompressInt(uint8_t *dest, int32_t value, int len) { + int i; + for (i = len - 1; i >= 0; i--) { + dest[i] = value % 91 + 33; + value /= 91; + } +} + +#if HAS_ADC +static int tncComment(uint8_t *buf) +{ + struct ao_data packet; + + ao_arch_critical(ao_data_get(&packet);); + + int16_t battery = ao_battery_decivolt(packet.adc.v_batt); + int16_t apogee = ao_ignite_decivolt(AO_SENSE_DROGUE(&packet)); + int16_t main = ao_ignite_decivolt(AO_SENSE_MAIN(&packet)); + + return sprintf((char *) buf, + "B:%d.%d A:%d.%d M:%d.%d", + battery/10, + battery % 10, + apogee/10, + apogee%10, + main/10, + main%10); +} +#endif + /** * Generate the plain text position packet. */ @@ -487,57 +518,45 @@ static int tncPositionPacket(void) int32_t latitude = ao_gps_data.latitude; int32_t longitude = ao_gps_data.longitude; int32_t altitude = ao_gps_data.altitude; + uint8_t *buf; + + if (altitude < 0) + altitude = 0; + altitude = (altitude * (int32_t) 10000 + (3048/2)) / (int32_t) 3048; + + buf = tncBuffer; + *buf++ = '!'; - uint16_t lat_deg; - uint16_t lon_deg; - uint16_t lat_min; - uint16_t lat_frac; - uint16_t lon_min; - uint16_t lon_frac; + /* Symbol table ID */ + *buf++ = '/'; - char lat_sign = 'N', lon_sign = 'E'; + latitude = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000; + longitude = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000; - if (latitude < 0) { - lat_sign = 'S'; - latitude = -latitude; - } +#define ALTITUDE_LOG_BASE 0.001998002662673f /* log(1.002) */ - if (longitude < 0) { - lon_sign = 'W'; - longitude = -longitude; - } + altitude = logf((float) altitude) * (1/ALTITUDE_LOG_BASE); - /* 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 / 100000; - - lon_deg = longitude / 10000000; - longitude -= lon_deg * 10000000; - longitude *= 60; - lon_min = longitude / 10000000; - longitude -= lon_min * 10000000; - lon_frac = longitude / 100000; + tncCompressInt(buf, latitude, 4); + buf += 4; + tncCompressInt(buf, longitude, 4); + buf += 4; - if (altitude < 0) - altitude = 0; + /* Symbol code */ + *buf++ = '\''; - 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, - lon_deg, lon_min, lon_frac, lon_sign, - altitude); + tncCompressInt(buf, altitude, 2); + buf += 2; + + *buf++ = 33 + ((1 << 5) | (2 << 3)); + +#if HAS_ADC + buf += tncComment(buf); +#else + *buf = '\0'; +#endif + + return buf - tncBuffer; } static int16_t |